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Subduction Zone
QUOTE
The source speaks of an object in BOTH rotation and translation and since you are proposing there is no movement of the plane therefore no translation these sources are irrelevant.
More evidence that NCN believes in a Flat Earth.

You really need to review your basic physics and learn what a frame of reference is.

QUOTE (->
 QUOTE The source speaks of an object in BOTH rotation and translation and since you are proposing there is no movement of the plane therefore no translation these sources are irrelevant.
More evidence that NCN believes in a Flat Earth.

You really need to review your basic physics and learn what a frame of reference is.

So far as I can tell, you start off by defining what you want to prove and then using it to come up with some consequences.

That is the way that proper science works.

QUOTE
While mathematically this works out because the units match, there is no real reason to believe the final algebra actually means anything.

Urkh!!??

Let me try to interpret: "You are right, but I don't see any reason to believe you."
Subduction Zone
QUOTE (Derek1148+Mar 22 2011, 05:12 AM)
Stop and they'll go away. They're like parasites, they feed off criticism.

Wrong, we feed off of foolishness. Look at the science and math and try to come up with legitimate complaints and then we might go away. Even Derek, no small foo himself, realized how foolish that last post of NCN's was.
Sithdarth
QUOTE
Kettle, meet Pot....Pot, meet Kettle....

Too bad for you that you started it quite awhile ago and you lost the argument.

QUOTE (->
 QUOTE Kettle, meet Pot....Pot, meet Kettle....

Too bad for you that you started it quite awhile ago and you lost the argument.

Oh, you mean the mountain of evidence such as, "wrong....wrong....no....not true...not applicable...etc...etc....etc"?

Nope and you've been reading long enough to know what I've actually presented. Nice try though.

QUOTE
Your mountain of evidence has been routinely to either dismiss a discussion altogether, or to claim something was previously discussed that was never discussed.

History clearly indicates otherwise.

QUOTE (->
 QUOTE Your mountain of evidence has been routinely to either dismiss a discussion altogether, or to claim something was previously discussed that was never discussed.

History clearly indicates otherwise.

Look back on your other postings and see just how many times your refutation of a topic was little more than saying. "wrong", yet you LATER claim that the topic was otherwise discussed. Rarely do you ever support your claim that someone's statement is wrong to the same standards you hold for yourself.

Must have forgotten this:
QUOTE
The linear velocity of any object that rolls, be they planes or batteries, is:

V_object = V_angular*r + V_surface (all of these being vector quantities)

This always works. For example, if a car drives by you on the road at 50 mph you see:

V_surface = 0 mph, V_angular*r = 50 mph, V_object = 50 mph

The guy in the car sees:

V_surface = -50 mph, V_angular*r = 50 mph, V_object = 0 mph (V_object being the velocity of the car with respect to the driver which better be zero or he's in trouble)

As you can see the Velocity of any object rolling without slipping depends both on its velocity relative to some reference frame and the velocity of that surface with respect to the same reference frame. A little bit of calculus, i.e. taking a derivative with respect to time tells us:

A_object = A_angular*r + A_surface

This and only this is needed to hold the plane back.

The key point to remember is that the basic equation of rolling given above applies to everything and anything that rolls without slipping. There are absolutely no exceptions. If it rolls without slipping and is undergoing a force on its center of mass and a force from the surface it is rolling on it must obey the same exact equations as any other object also rolling without slipping and undergoing a force on its center of mass and a force acting on its edge. Putting wings and an engine on something that is rolling without slipping does not in anyway change the rolling behavior. Indeed there is no way to change the rolling behavior of something that rolls without slipping. It is absolutely fixed. At best you can make it so that it slips but then it is no longer rolling without slipping and therefore you haven't changed the rolling without slipping behavior.

Source 1

Source 2

Source 3

All 3 of these sources say the same thing, with a few extraneous bits. Namely an accelerating belt will hold a plane back even if the wheels are frictionless.

Textbook 1 page 1
page 2
page 3

Classical Mechanics Textbook

These textbooks demonstrate a way to approach problems like this and I applied that approach to the problem at hand for three separate cases:

1) Constant speed belt:

F_net = F_thrust (these are the only two forces acting on the plane)

so:

M_p*A_p = F_thrust

and

A_p = F_thrust/M_p

2) Belt matching forward air speed of plane but in opposite direction:

M_p*A_p = F_thrust - F_belt = F_thrust - I*α/R

and X_plane = R*Θ - X_belt, V_plane = R*ω - V_belt, and A_p = R*α - A_belt

but X_belt in this case is 1/2*R*Θ (for the wheels of a plane moving 10mph relative to stationary on a belt moving -10mph relative to stationary R*Θ = 20 mph). So:

X_plane = 1/2*R*Θ, V_plane = 1/2*R*ω, and A_p = 1/2*R*α

A_p = F_thrust/M - I*α/(M*R) = F_thrust/M - I*(2*A_p)/(M*R^2)

A_p*(1 + 2*I/(M*R^2) = F_thrust/M

A_p = F_thrust/(M + 2*I/R^2)

Which of course can never be zero.

3) Belt matching the wheel speed of the plane in the opposite direction:

M_p*A_p = F_thrust - F_belt = F_thrust - I*α/R

In this case X_plane = R*Θ - X_belt, V_plane = R*ω - V_belt, and A_p = R*α - A_belt

A_p = F_thrust/M - I*α/(M*R) = F_thrust/M - I*(A_p + A_belt)/(M*R^2)

A_p + I*A_p/(M*R^2) = F_thrust/M - I*A_belt/(M*R^2)

A_p = (F_thrust*R^2 - I*A_belt)/(M*R^2(1 + I/M*R^2)) = (F_thrust*R^2 - I*A_belt)/(M*R^2 + I)

But we want A_p = 0 so:

0 = (F_thrust*R^2 - I*A_belt)/(M*R^2 + I)

F_thrust*R^2/(M*R^2 + I) = I*A_belt/(M*R^2 + I)

A_belt = (F_thrust*R^2)/I

or alternatively:

M_p*A_p = F_thrust - F_belt = F_thrust - I*α/R

and X_plane = R*Θ - X_belt, V_plane = R*ω - V_belt, and A_p = R*α - A_belt

but X_belt in this case must be R*Θ (but A_p = R*α - A_belt still holds so A_belt = R*α). So:

X_plane = 0, V_plane = 0, and A_p = 0

0 = F_thrust/M - I*α/(M*R) = F_thrust/M - I*A_belt/(M*R^2)

I*A_belt/(M*R^2) = F_thrust/M

A_belt = (F_thrust*R^2)/I

As you can see by the math the only one the holds the plane back is the third case. If you want to redo cases 2 and 3 with the belt going the other way just flip all the signs of anything with a _belt subscript. Of course then in case 3 A_p would no longer be zero and the plane would not be held back.

Oh and I might as well deal with relativistic effects on the belt while I'm at it. For Relativistic mass m_R = m*(1–v^2/c^2)^(–1/2) where m_r is relativistic mass and m is rest mass. Approximating the wheels as perfect rings with all the mass at the edge for simplicity the moment of inertia of the wheels is m_wheel*R^2 substituting in for relativistic mass the relativistic moment of inertia is m_wheel*(1–v^2/c^2)^(–1/2)*R^2. Now we go back to this equation:

A_belt = (F_thrust*R^2)/I and substitute for I

A_belt = (F_thrust*R^2)/( m_wheel*(1–v^2/c^2)^(–1/2)*R^2) = (F_thrust)/( m_wheel*(1–v^2/c^2)^(–1/2)) the R^2 cancel

Now F_thrust is constant but (1–v^2/c^2)^(–1/2) or 1/(1–v^2/c^2)^(1/2) goes to infinity in the limit of v = c. Thus A_belt goes to zero in the limit of v = c. This is the full consequence of relativity. You can accelerate forever and never get to the speed of light.

Another way to prove that you can accelerate forever at 1 g and never actually reach the speed of light. The reason is the Lorents Transformations for acceleration. Here v is the instantaneous velocity of the belt and u is the velocity of a particle as measured from someone in the rest frame of the belt. In this case we set u = 0 to calculate the acceleration of the belt we observe from outside the belt and the equation simplifies to:

a'_belt = a_belt/((1–v^2/c^2)^(–3/2)*1) which again approaches zero in the limit of v = c and thus a'_belt the acceleration we observe for the belt decreases to zero as we approach the speed of light even though from the perspective of someone on the belt it is still accelerating at a constant one g. Welcome to the paradoxical world of relativity.

Oh and it is very much the belt's frame of reference that matters since the bottoms of the wheels where the force of the accelerating belt is applied is in the reference frame of the belt.

QUOTE (->
 QUOTE The linear velocity of any object that rolls, be they planes or batteries, is:V_object = V_angular*r + V_surface (all of these being vector quantities)This always works. For example, if a car drives by you on the road at 50 mph you see:V_surface = 0 mph, V_angular*r = 50 mph, V_object = 50 mphThe guy in the car sees:V_surface = -50 mph, V_angular*r = 50 mph, V_object = 0 mph (V_object being the velocity of the car with respect to the driver which better be zero or he's in trouble)As you can see the Velocity of any object rolling without slipping depends both on its velocity relative to some reference frame and the velocity of that surface with respect to the same reference frame. A little bit of calculus, i.e. taking a derivative with respect to time tells us:A_object = A_angular*r + A_surfaceThis and only this is needed to hold the plane back.The key point to remember is that the basic equation of rolling given above applies to everything and anything that rolls without slipping. There are absolutely no exceptions. If it rolls without slipping and is undergoing a force on its center of mass and a force from the surface it is rolling on it must obey the same exact equations as any other object also rolling without slipping and undergoing a force on its center of mass and a force acting on its edge. Putting wings and an engine on something that is rolling without slipping does not in anyway change the rolling behavior. Indeed there is no way to change the rolling behavior of something that rolls without slipping. It is absolutely fixed. At best you can make it so that it slips but then it is no longer rolling without slipping and therefore you haven't changed the rolling without slipping behavior. Source 1 Source 2 Source 3 All 3 of these sources say the same thing, with a few extraneous bits. Namely an accelerating belt will hold a plane back even if the wheels are frictionless. Textbook 1 page 1 page 2 page 3 Classical Mechanics TextbookThese textbooks demonstrate a way to approach problems like this and I applied that approach to the problem at hand for three separate cases:1) Constant speed belt:F_net = F_thrust (these are the only two forces acting on the plane)so:M_p*A_p = F_thrustandA_p = F_thrust/M_p2) Belt matching forward air speed of plane but in opposite direction:M_p*A_p = F_thrust - F_belt = F_thrust - I*α/Rand X_plane = R*Θ - X_belt, V_plane = R*ω - V_belt, and A_p = R*α - A_beltbut X_belt in this case is 1/2*R*Θ (for the wheels of a plane moving 10mph relative to stationary on a belt moving -10mph relative to stationary R*Θ = 20 mph). So:X_plane = 1/2*R*Θ, V_plane = 1/2*R*ω, and A_p = 1/2*R*αA_p = F_thrust/M - I*α/(M*R) = F_thrust/M - I*(2*A_p)/(M*R^2)A_p*(1 + 2*I/(M*R^2) = F_thrust/MA_p = F_thrust/(M + 2*I/R^2)Which of course can never be zero.3) Belt matching the wheel speed of the plane in the opposite direction:M_p*A_p = F_thrust - F_belt = F_thrust - I*α/RIn this case X_plane = R*Θ - X_belt, V_plane = R*ω - V_belt, and A_p = R*α - A_beltA_p = F_thrust/M - I*α/(M*R) = F_thrust/M - I*(A_p + A_belt)/(M*R^2)A_p + I*A_p/(M*R^2) = F_thrust/M - I*A_belt/(M*R^2)A_p = (F_thrust*R^2 - I*A_belt)/(M*R^2(1 + I/M*R^2)) = (F_thrust*R^2 - I*A_belt)/(M*R^2 + I)But we want A_p = 0 so:0 = (F_thrust*R^2 - I*A_belt)/(M*R^2 + I)F_thrust*R^2/(M*R^2 + I) = I*A_belt/(M*R^2 + I)A_belt = (F_thrust*R^2)/Ior alternatively:M_p*A_p = F_thrust - F_belt = F_thrust - I*α/Rand X_plane = R*Θ - X_belt, V_plane = R*ω - V_belt, and A_p = R*α - A_beltbut X_belt in this case must be R*Θ (but A_p = R*α - A_belt still holds so A_belt = R*α). So:X_plane = 0, V_plane = 0, and A_p = 00 = F_thrust/M - I*α/(M*R) = F_thrust/M - I*A_belt/(M*R^2)I*A_belt/(M*R^2) = F_thrust/MA_belt = (F_thrust*R^2)/IAs you can see by the math the only one the holds the plane back is the third case. If you want to redo cases 2 and 3 with the belt going the other way just flip all the signs of anything with a _belt subscript. Of course then in case 3 A_p would no longer be zero and the plane would not be held back.Oh and I might as well deal with relativistic effects on the belt while I'm at it. For Relativistic mass m_R = m*(1–v^2/c^2)^(–1/2) where m_r is relativistic mass and m is rest mass. Approximating the wheels as perfect rings with all the mass at the edge for simplicity the moment of inertia of the wheels is m_wheel*R^2 substituting in for relativistic mass the relativistic moment of inertia is m_wheel*(1–v^2/c^2)^(–1/2)*R^2. Now we go back to this equation:A_belt = (F_thrust*R^2)/I and substitute for IA_belt = (F_thrust*R^2)/( m_wheel*(1–v^2/c^2)^(–1/2)*R^2) = (F_thrust)/( m_wheel*(1–v^2/c^2)^(–1/2)) the R^2 cancelNow F_thrust is constant but (1–v^2/c^2)^(–1/2) or 1/(1–v^2/c^2)^(1/2) goes to infinity in the limit of v = c. Thus A_belt goes to zero in the limit of v = c. This is the full consequence of relativity. You can accelerate forever and never get to the speed of light.Another way to prove that you can accelerate forever at 1 g and never actually reach the speed of light. The reason is the Lorents Transformations for acceleration. Here v is the instantaneous velocity of the belt and u is the velocity of a particle as measured from someone in the rest frame of the belt. In this case we set u = 0 to calculate the acceleration of the belt we observe from outside the belt and the equation simplifies to:a'_belt = a_belt/((1–v^2/c^2)^(–3/2)*1) which again approaches zero in the limit of v = c and thus a'_belt the acceleration we observe for the belt decreases to zero as we approach the speed of light even though from the perspective of someone on the belt it is still accelerating at a constant one g. Welcome to the paradoxical world of relativity.Oh and it is very much the belt's frame of reference that matters since the bottoms of the wheels where the force of the accelerating belt is applied is in the reference frame of the belt.

The only "Mountain of evidence" you have ever presented is the constant reposting (copy/paste) of the same flawed derivation of your original postulation.

Not flawed. It contains more then a derivation, I.E. cited sources.

QUOTE
You accuse others of levying "Strawman" arguments, yet you are the greatest offender in this realm of anyone else.

Nope.

QUOTE (->
 QUOTE You accuse others of levying "Strawman" arguments, yet you are the greatest offender in this realm of anyone else.

Nope.

I left this discussion earlier, not because I conceded any points, but because I came to realize I was engaging in a fruitless discussion with a couple 12 year olds with their hands over their ears for any discussion that didn't fit their predisposed conclusions.

Wait what was that about a pot and a kettle at the beginning and who said this a long time ago? You do realize that the only thing that destroys an argument and credibility faster than being a hypocrite is calling someone a hypocrite and then being hypocritical. You get extra points for doing it in the same breath.

QUOTE
I realized that no matter how salient a discussion was, it could never get past the, "la la la la, I can't hear you..." mentality of the participants.

Oh you mean one of the participates that admitted to being wrong? Well I guess that blows that out of the water. Too bad you can't even begin to make an actual point.

--------------------------------------------------------------
QUOTE (->
 QUOTE I realized that no matter how salient a discussion was, it could never get past the, "la la la la, I can't hear you..." mentality of the participants.

Oh you mean one of the participates that admitted to being wrong? Well I guess that blows that out of the water. Too bad you can't even begin to make an actual point.

--------------------------------------------------------------
As far as I can tell your "textbook" sources do absolutely nothing to support your proposal.

Except that they do.

QUOTE
The source speaks of an object in BOTH rotation and translation and since you are proposing there is no movement of the plane therefore no translation these sources are irrelevant.

The wheel is translating with respect to the surface it is rolling against. That surface is moving relative to the surface the observer is standing on. The net effect is that the plane appears not to translate to that observer. Again you need work on frames of reference.

QUOTE (->
 QUOTE The source speaks of an object in BOTH rotation and translation and since you are proposing there is no movement of the plane therefore no translation these sources are irrelevant.

The wheel is translating with respect to the surface it is rolling against. That surface is moving relative to the surface the observer is standing on. The net effect is that the plane appears not to translate to that observer. Again you need work on frames of reference.

As far as the unscientific sources go, all I see is unjustified claims that all the energy used to spin up a wheel is somehow available for linear motion.

No one claimed this.

QUOTE
This is also the claim in the first line of your derivation for case 3.

No it isn't.

QUOTE (->
 QUOTE This is also the claim in the first line of your derivation for case 3.

No it isn't.

So far as I can tell, you start off by defining what you want to prove and then using it to come up with some consequences.

I'm not even sure what you mean here.

QUOTE
While mathematically this works out because the units match, there is no real reason to believe the final algebra actually means anything.

Well aside from you not being anywhere near the point I used the equations and procedures developed by physicists to describe the world. Therefore my result describes the world. You cannot argue with Newton in the realm were Newton is applicable.

---------------------------------------------
QUOTE (->
 QUOTE While mathematically this works out because the units match, there is no real reason to believe the final algebra actually means anything.

Well aside from you not being anywhere near the point I used the equations and procedures developed by physicists to describe the world. Therefore my result describes the world. You cannot argue with Newton in the realm were Newton is applicable.

---------------------------------------------
Stop and they'll go away. They're like parasites, they feed off criticism.

Stop being a sore loser. The world isn't going to implode just because you were wrong. It didn't implode when I admitted I was wrong with something and it won't if you do.
Derek1148
QUOTE (Subduction Zone+Mar 22 2011, 05:16 AM)
Wrong, we feed off of foolishness.  Look at the science and math and try to come up with legitimate complaints and then we might go away.    Even Derek, no small foo himself, realized how foolish that last post of NCN's was.

Dammit, don't misinterpret my posts. I believe he is a genius (perhaps even a god).
Sithdarth
QUOTE
Dammit, don't misinterpret my posts. I believe he is a genius (perhaps even a god).

You might want to retract that in a second. Lets take a look shall we:

QUOTE (->
 QUOTE Dammit, don't misinterpret my posts. I believe he is a genius (perhaps even a god).

You might want to retract that in a second. Lets take a look shall we:

1) The physical system is under the constraints wheelspeed = beltspeed + planespeed and wheelspeed = beltspeed.

The resulting solution therefore can only have planespeed = 0.

Added two positive quantities to get zero.

QUOTE
The only resistive force presented by the belt/tire system is the so-called "rolling resistance".

Known to be false.

QUOTE (->
 QUOTE The only resistive force presented by the belt/tire system is the so-called "rolling resistance".

Known to be false.

While static friction between two objects remains constant (and is inapplicable in this instance, rolling resistance is not.

Rolling without resistance very much relies on static friction.

QUOTE
SD's perception of what is a proper frame of reference is also wrong. The case of the belt moving under the tire is exactly the same as a river flowing under a mill wheel. An observer on a boat floating down with the current would not measure any motion of the mill wheels towards him ... as it is he who is in fact approaching the fixed wheel. You might try to say there is no way to tell, but there is because the water pushing the wheel decelerates as it gives up energy to the wheel.

I shouldn't have to tell anyone how big of a mess this is in terms of reference frames.

QUOTE (->
 QUOTE SD's perception of what is a proper frame of reference is also wrong. The case of the belt moving under the tire is exactly the same as a river flowing under a mill wheel. An observer on a boat floating down with the current would not measure any motion of the mill wheels towards him ... as it is he who is in fact approaching the fixed wheel. You might try to say there is no way to tell, but there is because the water pushing the wheel decelerates as it gives up energy to the wheel.

I shouldn't have to tell anyone how big of a mess this is in terms of reference frames.

I'm sorry, did you see any linear motion of the battery in the frame of the creating force (gravity)? No? Neither did I. Therefore with no linear force there is no linear momentum. There was a lot of rotational momentum. So to describe the observed motion with his equations would be valid as long as you set the linear term to 0.

A battery moving down a ramp supposedly has no linear momentum.

QUOTE
Besides, since there was absolutely NO linear motion then there was no linear momentum so his equations don't apply.

See above.

QUOTE (->
 QUOTE Besides, since there was absolutely NO linear motion then there was no linear momentum so his equations don't apply.

See above.

No motion, no force (first law).

Obvious why this is wrong.

QUOTE
It is a misapplication of "static" friction since nothing is being "dragged" over a surface. (If the wheel was being used to turn or brake, on the other hand, static or dynamic comes into play).

See rolling without slipping.

QUOTE (->
 QUOTE It is a misapplication of "static" friction since nothing is being "dragged" over a surface. (If the wheel was being used to turn or brake, on the other hand, static or dynamic comes into play).

See rolling without slipping.

There are no conservation laws that depend on acceleration.

Hmm, conservation of gravitational potential energy anyone.

QUOTE
There is no such thing as a state of "acceleration" ... there is only a fixed velocity at a particular time and then, at a later time a new fixed velocity. That is acceleration.

Instantaneous acceleration anyone?

QUOTE (->
 QUOTE There is no such thing as a state of "acceleration" ... there is only a fixed velocity at a particular time and then, at a later time a new fixed velocity. That is acceleration.

Instantaneous acceleration anyone?

I see you screwed up again. Since you are only allowing yourself static friction and that is proportional to the normal force and the coefficient of static friction ... a very low number as you know ... there is consequently very little force available to do anything from the wheel.

We all know it isn't. It was then followed by this:

QUOTE
Try a rolling resistance of .01 or so ... we aren't talking about a block of rubber being dragged on concrete here.

The value is too small to make a difference. You are proven wrong.

Demonstrating a confusion of rolling resistance and static friction.

It continues but I think that makes the point nicely. I don't know he might be intelligent. His IQ might be 30 points higher than mine. But it is quite clear that he is far out of his depth here and does not have the conceptual or mathematical grounding to understand the physics going on here.
Derek1148
QUOTE (Sithdarth+Mar 22 2011, 05:35 AM)

You might want to retract that in a second. Lets take a look shall we:

Added two positive quantities to get zero.

Known to be false.

Rolling without resistance very much relies on static friction.

I shouldn't have to tell anyone how big of a mess this is in terms of reference frames.

A battery moving down a ramp supposedly has no linear momentum.

See above.

Obvious why this is wrong.

See rolling without slipping.

Hmm, conservation of gravitational potential energy anyone.

Instantaneous acceleration anyone?

We all know it isn't. It was then followed by this:

Demonstrating a confusion of rolling resistance and static friction.

It continues but I think that makes the point nicely. I don't know he might be intelligent. His IQ might be 30 points higher than mine. But it is quite clear that he is far out of his depth here and does not have the conceptual or mathematical grounding to understand the physics going on here.

Okay, maybe not the God. But still certainly a god.
RTS-Eng
QUOTE (Sithdarth+Mar 22 2011, 12:18 AM)

Nope and you've been reading long enough to know what I've actually presented. Nice try though.

I've been reading long enough to know when someone lies about their previous postings. The funny thing about such lying is that you don't even need a scientific background to follow it. All you need to do is read past postings.

Let's use my previous topic as a measure. If it was previously discussed (beyond saying "wrong"), then it should be a piece of cake to refer to the discussion that refuted it. You've only been here a few months, as have I, so it is not a lengthy search to locate this alleged refutation....right?

QUOTE (Sithdarth+Mar 22 2011, 12:18 AM)

Must have forgotten this:..........

LMAO....Isn't this the very same copy/pasted "Super proof" that you keep claiming is beyond refute that we are all to accept.....yet is the very same copy/pasted crap we are contesting in the first place?

QUOTE (Sithdarth+Mar 22 2011, 12:18 AM)

Not flawed. It contains more then a derivation, I.E. cited sources.

Sithdarth
QUOTE
I've been reading long enough to know when someone lies about their previous postings. The funny thing about such lying is that you don't even need a scientific background to follow it. All you need to do is read past postings.

There is only one liar here. I recommend using a mirror to find him.

QUOTE (->
 QUOTE I've been reading long enough to know when someone lies about their previous postings. The funny thing about such lying is that you don't even need a scientific background to follow it. All you need to do is read past postings.

There is only one liar here. I recommend using a mirror to find him.

Let's use my previous topic as a measure. If it was previously discussed (beyond saying "wrong"), then it should be a piece of cake to refer to the discussion that refuted it. You've only been here a few months, as have I, so it is not a lengthy search to locate this alleged refutation....right?

You'll have to be more specific.

QUOTE
LMAO....Isn't this the very same copy/pasted "Super proof" that you keep claiming is beyond refute that we are all to accept.....yet is the very same copy/pasted crap we are contesting in the first place?

Proof is proof. I have proof you don't have proof. I am right you are wrong. I've proven my case you haven't. You started insulting me when it was obvious you lost. You also slunk away an hid when it was obvious you lost only to come back when you thought you could catch me in a contradiction. You failed miserably. You will not follow proper debate etiquette. You no longer have any business being here.

QUOTE (->
 QUOTE LMAO....Isn't this the very same copy/pasted "Super proof" that you keep claiming is beyond refute that we are all to accept.....yet is the very same copy/pasted crap we are contesting in the first place?

Proof is proof. I have proof you don't have proof. I am right you are wrong. I've proven my case you haven't. You started insulting me when it was obvious you lost. You also slunk away an hid when it was obvious you lost only to come back when you thought you could catch me in a contradiction. You failed miserably. You will not follow proper debate etiquette. You no longer have any business being here.

Nope they don't.

QUOTE
I didn't say that I never read your sources. I said I didn't read them when you posted them.

I never alleged that you didn't. Why so defensive? Maybe because you know you are wrong? Also, thanks for admitting you have no interest in a proper debate once again.

QUOTE (->
 QUOTE I didn't say that I never read your sources. I said I didn't read them when you posted them.

I never alleged that you didn't. Why so defensive? Maybe because you know you are wrong? Also, thanks for admitting you have no interest in a proper debate once again.

Nope. Also distinct lack of evidence. Once again you loose. It would be a good idea to leave before you choke on your foot.
Derek1148
Come on, at least admit there is no question here. What you are saying is that we ignore the laws of physics and simply look at the math. Okay if the conveyor moves in the opposite direction of a vehicle's forward motion, at the same speed, at the same time, and there is no slippage, there will be no forward motion. Okay dammit, I accept that. Is that it?
Sithdarth
QUOTE
Come on, at least admit there is no question here. What you are saying is that we ignore the laws of physics and simply look at the math.

Well only things like material limitations and rolling resistance. This happens all the time in physics. I could amaze you with the seemingly important things that are ignored when say describing the behavior of electrons in a metal and at the same time the very good predictions that still come from the descriptions.

QUOTE (->
 QUOTE Come on, at least admit there is no question here. What you are saying is that we ignore the laws of physics and simply look at the math.

Well only things like material limitations and rolling resistance. This happens all the time in physics. I could amaze you with the seemingly important things that are ignored when say describing the behavior of electrons in a metal and at the same time the very good predictions that still come from the descriptions.

Okay if the conveyor moves in the opposite direction of a vehicle's forward motion, at the same speed, at the same time, and there is no slippage, there will be no forward motion. Okay dammit, I accept that. Is that it?

More or less if you don't have any interest in the mechanics that makes that happen.
Derek1148
QUOTE (Sithdarth+Mar 22 2011, 06:24 AM)
More or less if you don't have any interest in the mechanics that makes that happen.

But, do you believe you could stop a plane from forward motion by the rearward motion of a conveyor belt? Not a "thought problem plane." A real plane?
Sithdarth
QUOTE
But, do you believe you could stop a plane from forward motion by the rearward motion of a conveyor belt? Not a "thought problem plane." A real plane?

That depends entirely on what you mean by a real plane, how long I have to stop it for, if you care if it gets broken or not, and how much money you're willing to give me.

An RC model of a 747 that is capable of flight, but uses props instead of jet engines, that you don't care if I break, and for a couple of seconds certainly. Heck I might even be able to do an ultra light assuming it has a relatively weak engine, good sized wheels, and again you don't care that it's probably going to get destroyed in the process. The biggest impediment to doing this full size is that it would be expensive and it would break. Well and you'd only get a few seconds or less of data.
Derek1148
QUOTE (Sithdarth+Mar 22 2011, 06:51 AM)
That depends entirely on what you mean by a real plane, how long I have to stop it for, if you care if it gets broken or not, and how much money you're willing to give me.

See, if you had said that at the beginning then I would have agreed with you. Yeah, I accept your answer.
NoCleverName
Well, it took some time and study last night, but I'd say S.Darth that you have the WRONG RESULT for the RIGHT REASON. And why it wasn't so blindingly obvious before I'll never know. Maybe the reason was because you neglected to take this same effect into account for the other cases.

An object certainly has "rotational inertia". And of course we know the total energy in the object is divided between the linear and rotational camps. For the object rolling down a upward-moving ramp the force needed to keep in place is related to moment of inertia ... for example to keep the cylinder in place the upward acceleration (yes, acceleration) of the belt must be 2g sin(theta).

However, note that the belt is powering the cylinder (it's now going faster than it would have in free-fall, as it were) and the reactive force against that powering force is against the belt. As the cylinder overcomes inertia and gains angular velocity, it tracks down the belt ... but "new" belt is being supplied just as rapidly and it gains no advance towards the ground. I suppose one could make the argument that in reaction to the linear force resulting from gravity and the normal force, some energy is used to create a countering force.

That there is no inherent motion along with the belt of a spinning object (in the perfectly balanced case) is fairly easily demonstrated. Run the battery experiment on a level surface. You'll have to get the battery going slightly to break static friction but once you do you see the battery pretty much spins in place at what ever rate you are able to input to it and still have "rolling without slipping". If there were an inherent tendency to create linear motion then you would see the battery draw nearer (why would the "inherent" force suddenly go away just because the ramp isn't angled?)

(By the way, it's quite a bit more difficult, but you CAN get the battery to stay in place by pulling the paper DOWN the ramp).

This "spinning in place" is what we normally expect to see. Now, does this spinning battery, powered by the belt, have any inherent extra resistance to FUTURE lateral motion? No. Even if you suppose that in the ramp case there was a division of labor between rotational and linear motion (to counter the "virtual motion" imposed by gravity) in this case there was never any opposing linear motion to begin with so ALL the energy supplied by the belt went into angular motion. That being the case, if the wheel WERE to give up angular energy, it would have to slow down. E.G., You don't get to count the belt moving under the wheel as linear motion of the wheel.

So, in essence a fast spinning object isn't all of a sudden "heavier" or "harder to push around" just because it's rotating (even accelerating). If all the wheel's energy is already stored as rotational energy there's none left to resist linear motion. To the extent that FUTURE linear motion changes the energy balance, well, it does but it does so incrementally. It can't draw upon what's in the bank already. Further, the wheel is powered by the belt, not the plane and it's reactive force is directed to that same belt. If the plane moves against the belt, then it will require it's OWN energy to supply power ITS contribution to the wheel speed...the belt is doing its part independently.
Subduction Zone
Oh my oh my. Wrong.

QUOTE
However, note that the belt is powering the cylinder (it's now going faster than it would have in free-fall, as it were) and the reactive force against that powering force is against the belt. As the cylinder overcomes inertia and gains angular velocity, it tracks down the belt ... but "new" belt is being supplied just as rapidly and it gains no advance towards the ground.

QUOTE (->
 QUOTE However, note that the belt is powering the cylinder (it's now going faster than it would have in free-fall, as it were) and the reactive force against that powering force is against the belt. As the cylinder overcomes inertia and gains angular velocity, it tracks down the belt ... but "new" belt is being supplied just as rapidly and it gains no advance towards the ground.

I suppose one could make the argument that in reaction to the linear force resulting from gravity and the normal force, some energy is used to create a countering force.

Yes, I suppose you could make that argument. If the forces are equal on an object what happens to it?

QUOTE

That there is no inherent motion along with the belt of a spinning object (in the perfectly balanced case) is fairly easily demonstrated

What is "inherent motion"? I must have been sick the day they covered that in physics class.

QUOTE (->
 QUOTE That there is no inherent motion along with the belt of a spinning object (in the perfectly balanced case) is fairly easily demonstrated

What is "inherent motion"? I must have been sick the day they covered that in physics class.

Run the battery experiment on a level surface. You'll have to get the battery going slightly to break static friction but once you do you see the battery pretty much spins in place at what ever rate you are able to input to it and still have "rolling without slipping"

Wrong on two counts. If you "break static friction" you are by definition sliding. So you are not rolling without slipping. Second even if you do "break static friction" there is still kinetic friction and you are claiming that an object with an unbalanced force on it will stay in place. and that breaks Newton's Law of Motion F =mA.

QUOTE
If there were an inherent tendency to create linear motion then you would see the battery draw nearer (why would the "inherent" force suddenly go away just because the ramp isn't angled?

Once again with the "inherent" nonsense. Please rewrite this so it makes some sort of sense.

QUOTE (->
 QUOTE If there were an inherent tendency to create linear motion then you would see the battery draw nearer (why would the "inherent" force suddenly go away just because the ramp isn't angled?

Once again with the "inherent" nonsense. Please rewrite this so it makes some sort of sense.

(By the way, it's quite a bit more difficult, but you CAN get the battery to stay in place by pulling the paper DOWN the ramp).

Only if you have been smoking strange substances before you do your tests.

QUOTE
So, in essence a fast spinning object isn't all of a sudden "heavier" or "harder to push around" just because it's rotating (even accelerating). If all the wheel's energy is already stored as rotational energy there's none left to resist linear motion. To the extent that FUTURE linear motion changes the energy balance, well, it does but it does so incrementally. It can't draw upon what's in the bank already. Further, the wheel is powered by the belt, not the plane and it's reactive force is directed to that same belt. If the plane moves against the belt, then it will require it's OWN energy to supply power ITS contribution to the wheel speed...the belt is doing its part independently.

No one ever claimed that an object was "heavier", except for maybe you. This is all pretty much nonsense that does not mean anything.

I have another treadmill question for you NCN.

Does this YouTube video prove that a vehicle can move directly downwind faster than the wind powered only by the wind? Depending on your answer I may ask you to participate in another debate on elsewhere on this forum.
NoCleverName
SD ... don't get me wrong, I more or less agree with Darth's model of the battery and the ramp ... I just don't know how it really works and if that is applicable to the instant problem. I've always pretty much gone back and forth in my head between "he's right" and "he's wrong" but because I've seen too much misapplied math in my day plus the experimental results are ambiguous I can't get a handle on what's actually happening so there's no point is just blindly agreeing.

That's the scientific method, isn't it? (It's not, Darth, just coming up with an idea and then finding something to support it. The idea has to withstand all attempts to FALSIFY it).

As to the wind-powered deal, what's the controversy? As a long time sailor I know full well you can outperform the wind. You should see some of those ice-boats go. In sailing it's called "apparent wind" and it effects both velocity and angle of attack.

Is there some other opinion I should know about?

Edit ... Oh, now I see it's "directly down wind" ... I suppose if you had some cool airfoil one you got going quick enough you could generate additional lift with the new apparent wind. I'll have to check it out.

Edit Again: Ha ... even cooler than I expected. I have no idea whatsoever how to start to analyze that ... particularly in light of the fact the plane isn't supposed to take off!
NoCleverName
If nothing else the wind-powered car contraption is NOT a closed system. Energy is being supplied externally.
Subduction Zone
Very good, yes it is a case of directly downwind faster than the wind. The guys that made that little cart went on to build a man sized one with a record ratified by NALSA.
NoCleverName
Well, after some thought and study I now know how the battery-on-a-ramp works, how in relates to my contradictory experiments, and how all this is applicable to the plane-on-a-conveyor. Short answer to the last question: it isn't.

First an observation about the "rules of the game". In this version the belt is essentially hard-linked to the wheels since both are defined to be going at the same speed. That is the only rule. However, there always seems to be an "unwritten" rule number 2 and that is the plane can't do anything to cause rule 1 to be broken. Of course, this is where the game breaks down because the rules are stacked in favor of "plane can't move".

But in "real life" there is no rule 2 so the system would go into a "feedback loop" if it attempted to obey rule 1 in the face of the plane moving forward in space. Therefore, this is an uninteresting problem.

Realizing the "true myth" cannot be solved we are now simply interested in if the belt, via the wheel, can do ANYTHING to prevent the plane from moving forward. To this end we aren't going to invoke esoteric phenomena like "relativistic wheel speed" which effectively increases the mass the plane must move nor on the other end will we bring in other factors like practical limits on wheel and bearing performance.

It has been proposed that the plane would encounter a retarding force by trying to push against a wheel that's currently being accelerated by the belt (i.e., you'll encounter lateral resistance if you try to push against an object undergoing angular acceleration).

To show that this phenomena actually existed, an experiment was performed that had a battery rolling down an incline that was itself be accelerated uphill. Observing that the battery seemed to be "held in place" the conclusion was reached that, yes, there was a "retarding force" created by the accelerating surface.

On the other hand, attempts to replicate this experiment with more precision and a wider set of parameters drew results that weren't totally consistent with the theory. To wit, an object could be held in place by a variety of upward ramp speed accelerations, not just one. And then the phenomena was entirely missing if the experiment was performed on the horizontal: the objects "stayed in place": if there was an "uphill" force then the objects should have gone backwards since there was no other force (like gravity) to oppose that motion.

As it turns out, the answer to these results has absolutely nothing to do with an "opposing force generated by angular acceleration" but has everything to do with simple traction.

Consider a toy wagon on a ramp with its "brakes" on. It is held in place by the static friction of its wheels. (At a steep enough angle there is no longer sufficient downward force on the wheels to generate enough friction to hold and the wagon slides). Releasing the brakes allows the wagon to roll down hill. If the wheels are allowed to turn freely, then the wheel-speed matches the speed over the surface (rolling without slipping). This "freewheeling" also means that the contact point between wheel and surface is instantaneously motionless and static friction (i.e. traction) between the surfaces still applies.

The acceleration of the wagon is strictly a function of the force of gravity and the ramp inclination (specifically, the sine of the ramp angle). Observe that if static friction (traction) is high enough, freewheeling wheels can be subject to somewhat higher accelerations than that of gravity and still "stick to the pavement".

"Pulling the ramp uphill" is exactly one such acceleration that does not cause a freewheeling wheel to skid. If the ramp is accelerated uphill at least as rapidly as the wagon would naturally go downhill then the wagon will appear to stay in place. This is because the traction force of the wheels is great enough to prevent the wagon from making faster progress down the ramp than "new ramp" is being supplied to it. Essentially, the wagon is being drawn uphill as fast as it is rolling downhill. Traction keeps it in place.

You can visualize this in another way. If the brakes were on, you could accelerate the wagon uphill by pulling on the ramp (but no faster than would break traction). This shows that progress along the ramp surface without slipping is dictated by traction.

Any "extra" acceleration supplied beyond that to keep the wagon "in place" simply goes to spinning the wheels faster (because there is no opposing force to speeding up the freewheeling wheels).

So this explains all the phenomena of the second experimental run. The "slow" pull back speeds were sufficient to hold the objects in place based on the ramp angle used (6 degrees and I believe about 2 m/s/s). "Faster than necessary" acceleration merely went to speeding up the wheels in place (and, once off the moving ramp those energized wheels caused the object to accelerate away, proving that extra, unnecessary energy was added to the system).

On the flats, normal inertia kept the object in place as the ramp was pulled out from under it. Traction force allowed the motion to become a torque which increased angular speed.

Thus, the battery-on-a-ramp experiment DID NOT reveal a retarding linear force to angular acceleration.

Therefore, this "force" is not available to hold back the "plane on a conveyor" … which can move forward unabated (as long as it is allowed to break rule 2!).
Lasand
Good post NCN.
Lasand
The Russian version diabolically insists that the wheel/axle and belt must behave as if they were meshed gears. How bizarre is that?
Sithdarth
QUOTE
Well, after some thought and study I now know how the battery-on-a-ramp works, how in relates to my contradictory experiments, and how all this is applicable to the plane-on-a-conveyor. Short answer to the last question: it isn't.

That would be wrong.

QUOTE (->
 QUOTE Well, after some thought and study I now know how the battery-on-a-ramp works, how in relates to my contradictory experiments, and how all this is applicable to the plane-on-a-conveyor. Short answer to the last question: it isn't.

That would be wrong.

First an observation about the "rules of the game". In this version the belt is essentially hard-linked to the wheels since both are defined to be going at the same speed. That is the only rule. However, there always seems to be an "unwritten" rule number 2 and that is the plane can't do anything to cause rule 1 to be broken. Of course, this is where the game breaks down because the rules are stacked in favor of "plane can't move".

But in "real life" there is no rule 2 so the system would go into a "feedback loop" if it attempted to obey rule 1 in the face of the plane moving forward in space. Therefore, this is an uninteresting problem.

No. The plane can't break rule 1 because its thrust to weight ratio is assumed to be less than the coefficient of static friction and therefore it can never cause rolling without slipping. Therefore once the acceleration that matches the thrust is achieved and since the thrust of the plane is essentially constant the plane will no longer accelerate with respect to the ground. From there getting belt speed and wheel speed to match is simply a matter of accelerating the belt a little bit extra for a little extra time. That is as long as we aren't allowing instant reactions.

QUOTE
It has been proposed that the plane would encounter a retarding force by trying to push against a wheel that's currently being accelerated by the belt (i.e., you'll encounter lateral resistance if you try to push against an object undergoing angular acceleration).

F=ma. The plane accelerates under a thrust force the only way to make it not accelerate is by an equal and opposite force. You cannot defy Newton.

QUOTE (->
 QUOTE It has been proposed that the plane would encounter a retarding force by trying to push against a wheel that's currently being accelerated by the belt (i.e., you'll encounter lateral resistance if you try to push against an object undergoing angular acceleration).

F=ma. The plane accelerates under a thrust force the only way to make it not accelerate is by an equal and opposite force. You cannot defy Newton.

As it turns out, the answer to these results has absolutely nothing to do with an "opposing force generated by angular acceleration" but has everything to do with simple traction.

F=ma. Can't violate Newton's laws of motion.

QUOTE
Consider a toy wagon on a ramp with its "brakes" on. It is held in place by the static friction of its wheels. (At a steep enough angle there is no longer sufficient downward force on the wheels to generate enough friction to hold and the wagon slides). Releasing the brakes allows the wagon to roll down hill. If the wheels are allowed to turn freely, then the wheel-speed matches the speed over the surface (rolling without slipping). This "freewheeling" also means that the contact point between wheel and surface is instantaneously motionless and static friction (i.e. traction) between the surfaces still applies.

The acceleration of the wagon is strictly a function of the force of gravity and the ramp inclination (specifically, the sine of the ramp angle). Observe that if static friction (traction) is high enough, freewheeling wheels can be subject to somewhat higher accelerations than that of gravity and still "stick to the pavement".

"Pulling the ramp uphill" is exactly one such acceleration that does not cause a freewheeling wheel to skid. If the ramp is accelerated uphill at least as rapidly as the wagon would naturally go downhill then the wagon will appear to stay in place. This is because the traction force of the wheels is great enough to prevent the wagon from making faster progress down the ramp than "new ramp" is being supplied to it. Essentially, the wagon is being drawn uphill as fast as it is rolling downhill. Traction keeps it in place.

You can visualize this in another way. If the brakes were on, you could accelerate the wagon uphill by pulling on the ramp (but no faster than would break traction). This shows that progress along the ramp surface without slipping is dictated by traction.

F=ma. The wagon cannot be drawn uphill without a force acting on it.

QUOTE (->
 QUOTE Consider a toy wagon on a ramp with its "brakes" on. It is held in place by the static friction of its wheels. (At a steep enough angle there is no longer sufficient downward force on the wheels to generate enough friction to hold and the wagon slides). Releasing the brakes allows the wagon to roll down hill. If the wheels are allowed to turn freely, then the wheel-speed matches the speed over the surface (rolling without slipping). This "freewheeling" also means that the contact point between wheel and surface is instantaneously motionless and static friction (i.e. traction) between the surfaces still applies.The acceleration of the wagon is strictly a function of the force of gravity and the ramp inclination (specifically, the sine of the ramp angle). Observe that if static friction (traction) is high enough, freewheeling wheels can be subject to somewhat higher accelerations than that of gravity and still "stick to the pavement"."Pulling the ramp uphill" is exactly one such acceleration that does not cause a freewheeling wheel to skid. If the ramp is accelerated uphill at least as rapidly as the wagon would naturally go downhill then the wagon will appear to stay in place. This is because the traction force of the wheels is great enough to prevent the wagon from making faster progress down the ramp than "new ramp" is being supplied to it. Essentially, the wagon is being drawn uphill as fast as it is rolling downhill. Traction keeps it in place.You can visualize this in another way. If the brakes were on, you could accelerate the wagon uphill by pulling on the ramp (but no faster than would break traction). This shows that progress along the ramp surface without slipping is dictated by traction.

F=ma. The wagon cannot be drawn uphill without a force acting on it.

Any "extra" acceleration supplied beyond that to keep the wagon "in place" simply goes to spinning the wheels faster (because there is no opposing force to speeding up the freewheeling wheels).

F=ma. If the acceleration is occurring it is producing a force. The wheels do indeed speed up and by speeding up they change the linear motion of the wagon because they are rolling without slipping. V_com = V_surface + V_angular this cannot be violated while rolling without slipping.

QUOTE
So this explains all the phenomena of the second experimental run. The "slow" pull back speeds were sufficient to hold the objects in place based on the ramp angle used (6 degrees and I believe about 2 m/s/s). "Faster than necessary" acceleration merely went to speeding up the wheels in place (and, once off the moving ramp those energized wheels caused the object to accelerate away, proving that extra, unnecessary energy was added to the system).

On the flats, normal inertia kept the object in place as the ramp was pulled out from under it. Traction force allowed the motion to become a torque which increased angular speed.

Thus, the battery-on-a-ramp experiment DID NOT reveal a retarding linear force to angular acceleration.

Therefore, this "force" is not available to hold back the "plane on a conveyor" … which can move forward unabated (as long as it is allowed to break rule 2!).

Absolutely wrong and very easy to see why. For your explanation to come even remotely close to working we have to accept that Newton's Laws of motion don't work. We know this isn't the case so we know your explanation can't work.
RTS-Eng
QUOTE (Sithdarth+Mar 23 2011, 12:25 PM)
From there getting belt speed and wheel speed to match is simply a matter of accelerating the belt a little bit extra for a little extra time. That is as long as we aren't allowing instant reactions.

That violates your definition of the conveyor. How do you justify that in one direction but not allow it in the other direction? The only justification for that is to come right out and say the conveyor is defined to hold the plane in place.
Sithdarth
Ahem:

QUOTE
That is as long as we aren't allowing instant reactions.

It would be nice if you would read the entirety of what you quote.
NoCleverName
... and I was expecting a bunch of Wrong Wrong Wrong's Darth. I'm disappointed.

You've already got your F=ma ... or hadn't you noticed the ramp moving upward under YOUR acceleration. You are really slipping. Do I have to explain this as to a child?

1) The wagon is on the ramp with the brakes on.

2) You begin to accelerate the ramp upwards. The wagon keeps in position fixed on the ramp (moving up WITH IT) because of static friction. Just don't pull too fast!

3) You slowly "ease off" the brakes. Now the wagon is free to move downhill. It makes some progress against it's position on the ramp but it's still going uphill as seen by an outside observer.

4) You ease off more so there is even less braking force. Now gravity can add additional acceleration but the ramp is still carrying everything upward because there still is some resistance against the belt.

5) Release the brakes entirely. The wagon now falls with gravity, but because the wheels are still "rolling without slipping" they are subject to an uphill force because they are still instantaneously motionless.

6) The wagon is now motionless to an outside observer. Why? Because it can't make anymore progress down the ramp than gravity can accelerate it (and still not slip the wheels). "New ramp" is being supplied instantaneously to counter any progress it makes.

7) Any additional, unnecessary acceleration goes to speeding up the wheels (which are free to do so due to their bearings). Because we haven't induced "slipping", the wheels, no matter what speed they go, always present static friction.

Simple enough for you?

Oh, I like the way you say there's "no force" to carry the wagon uphill. I guess that means there's "no force" to stop the plane, either.

You also seem to be the only one on the planet who thinks the Russian version doesn't create a feedback loop if the plane moves.

My theory explains both your experiment and mine. Yours doesn't. You need a new theory.
RTS-Eng
QUOTE (Sithdarth+Mar 23 2011, 12:38 PM)
It would be nice if you would read the entirety of what you quote.

You should read your own postings with a little more care. It makes no difference which model you choose. Pulling the wheel backward still violates your definition. And if you weren't so afraid of being found in error, you would be willing to discuss why the wheel must move forward even when there is an instantaneous reaction.
NoCleverName
I see a few people are posting now so this will probably get out of sequence.

Strictly speaking Darth is more or less right that there is no FORCE holding the object in place.

It is more accurate to say the object is falling (since the COM is not above the center of support) and this "falling" proceeds to a new support position further down the ramp from which point the falling continues.

However, in this case, a new "point of support" comes up to meet the falling object, just in time to prevent actual downward progress (but not rotation). This happens from instant-to-instant.

The result is the same ... the object rotates in place (no lateral motion needed) therefore there is no need to create a retarding force.

I thought it would be easier to understand as up upward force from the ramp balancing the downward force from gravity ... but that wouldn't be right.
The validity of the "Russian" version and its fantasy conveyor aside, I do not like Sithdarths mathematical analysis of the problem. Especially the wording of scenario 3. The what we want line is misleading because it has not been ascertained at that stage that the Inertia will be sufficient to retard the plane. It should read If Ap=0. Sithdarth's notation is also hard to follow. He may save his reaction I already know what it is. The problem comes down to the thrust of the engines mass of the plane resulting in acceleration with opposing forces of friction and rolling resistance. By accelerating the wheels gives them Inertia which requires to be overcome enough inertia and the opposing forces become sufficient to stop acceleration.
I will read any replies when I get home from work.
NCN I would also appreciate how you derived your rolling resistance for the 777.
boit
NCN. I seem to agree with all your points but am chocking at point number seven (#7). How does extra belt acceleration goes into spinning the wheel faster and not generate a force to drug it back? You yourself said there is such a force and that's why you were laughing at sidart for allegedly claiming there was no such force. Do you concur with him then? Am confused.
Sithdarth
QUOTE
6) The wagon is now motionless to an outside observer. Why? Because it can't make anymore progress down the ramp than gravity can accelerate it (and still not slip the wheels). "New ramp" is being supplied instantaneously to counter any progress it makes.

I.E. the exact force I postulated is being applied to the wagon by the acceleration of the belt.

QUOTE (->
 QUOTE 6) The wagon is now motionless to an outside observer. Why? Because it can't make anymore progress down the ramp than gravity can accelerate it (and still not slip the wheels). "New ramp" is being supplied instantaneously to counter any progress it makes.

I.E. the exact force I postulated is being applied to the wagon by the acceleration of the belt.

7) Any additional, unnecessary acceleration goes to speeding up the wheels (which are free to do so due to their bearings). Because we haven't induced "slipping", the wheels, no matter what speed they go, always present static friction.

F=ma. The force comes from the acceleration of the wheels. If it didn't then the cart could not roll down a stationary ramp. Newton's Laws apply so the force is proportional to the acceleration. If the acceleration is increased the force must be increased.

QUOTE
Simple enough for you?

Except the bits that are wrong.

QUOTE (->
 QUOTE Simple enough for you?

Except the bits that are wrong.

Oh, I like the way you say there's "no force" to carry the wagon uphill. I guess that means there's "no force" to stop the plane, either.

Perhaps you need reading glasses. Let me quote myself:

QUOTE
F=ma. The wagon cannot be drawn uphill without a force acting on it.

QUOTE (->
 QUOTE F=ma. The wagon cannot be drawn uphill without a force acting on it.

You also seem to be the only one on the planet who thinks the Russian version doesn't create a feedback loop if the plane moves.

Obviously wrong.

QUOTE
My theory explains both your experiment and mine. Yours doesn't. You need a new theory.

1) Your theory breaks the most basic laws of Mechanics

2) I predicted the effect, which you denied for quite some time, based on my knowledge of mechanics. Ergo I understand what is going on much better than you do.

3) My theory, and it isn't really a theory since we know Newtonian mechanics works and we know I applied it properly, perfectly explains both experiments. I told you before if you want to make the sort of quantitative comparisons you are trying to make you need a much more sophisticated experimental setup. I can almost guarantee that your acceleration in each run is roughly the same and then you level out to a constant speed that is different for different runs. Actually more likely you start of with a high acceleration that gradually tapers off as you go. There is also probably a good deal of rolling resistance that needs to be accounted for that is occurring at the bearings. Of course since you won't share any of your experimental data, the video, I can't actually help you find the flaw for sure.

QUOTE (->
 QUOTE My theory explains both your experiment and mine. Yours doesn't. You need a new theory.

1) Your theory breaks the most basic laws of Mechanics

2) I predicted the effect, which you denied for quite some time, based on my knowledge of mechanics. Ergo I understand what is going on much better than you do.

3) My theory, and it isn't really a theory since we know Newtonian mechanics works and we know I applied it properly, perfectly explains both experiments. I told you before if you want to make the sort of quantitative comparisons you are trying to make you need a much more sophisticated experimental setup. I can almost guarantee that your acceleration in each run is roughly the same and then you level out to a constant speed that is different for different runs. Actually more likely you start of with a high acceleration that gradually tapers off as you go. There is also probably a good deal of rolling resistance that needs to be accounted for that is occurring at the bearings. Of course since you won't share any of your experimental data, the video, I can't actually help you find the flaw for sure.

The result is the same ... the object rotates in place (no lateral motion needed) therefore there is no need to create a retarding force.

F=ma. Gravity is acting on the battery therefore in order for a to be zero there must be an opposing force.

QUOTE
I thought it would be easier to understand as up upward force from the ramp balancing the downward force from gravity ... but that wouldn't be right.

It would in fact be precisely right.

----------------------------------------------------------------------

QUOTE (->
 QUOTE I thought it would be easier to understand as up upward force from the ramp balancing the downward force from gravity ... but that wouldn't be right.

It would in fact be precisely right.

----------------------------------------------------------------------

You should read your own postings with a little more care. It makes no difference which model you choose. Pulling the wheel backward still violates your definition. And if you weren't so afraid of being found in error, you would be willing to discuss why the wheel must move forward even when there is an instantaneous reaction.

Nope. Clearly not the case. Your foot must taste good. (It should be obvious to anyone reading with care that the two sentences that were quoted clearly indicate that the slowing of the wheel applies only to the non-instantaneous reaction case.) We've been over how you are horribly wrong about how infinitesimal quantities work in very great detail. But just so we're clear again for a finite distance to be traversed in an infinitesimal time requires an infinite velocity which clearly the plane cannot have.

----------------------------------------------------------------------

QUOTE
You yourself said there is such a force and that's why you were laughing at sidart for allegedly claiming there was no such force. Do you concur with him then? Am confused.

You and me both since I never claimed that.
NoCleverName
Your so-called "effect" is merely a coincidence of the math that the speeds of both the belt and the wheels have to be the same for the object to be held in place.

Do you seriously believe that you "predicted" an object could be held in place by a moving ramp?

Boit: The gears shift in this model depending on the regime.

1) When the wagon's "brakes are on" (even partially) then the wagon is being forced by the ramp to gain altitude.

2) With the brakes off and ramp acceleration exactly same as gravity then we have the "falling in place" regime where a new point of support instantaneously arrives "just in time" to keep the object from "falling over" down the ramp. But then this new point also isn't under the center of mass so the object "falls" again. Ad infinitum.

Since the "falling" is effectively "around" the support point (kind of a reversal where the support point acts as the center of rotation and the COM of the object rotates around it) a rotation of the entire object is generated.

3) When the acceleration is beyond that needed to just balance gravity, a torque is developed at the support point against the COM of the object, thus spinning it faster. Of course, new "support points" are supplied again ... just in time ... to keep the object from progressing down the ramp.

This would also be similar to the object on the horizontal. With any kind of luck you can get the wheel spinning without slipping if you pull with care. However in practical experiments, many times the object is dragged towards you due to static friction (in worst cases no spinning at all is induces, you just end up dragging it).
RTS-Eng
QUOTE (Sithdarth+Mar 23 2011, 03:30 PM)
We've been over how you are horribly wrong about how infinitesimal quantities work in very great detail. But just so we're clear again for a finite distance to be traversed in an infinitesimal time requires an infinite velocity which clearly the plane cannot have.

No we haven't been over it. Your only responses have been "No"..."Wrong"...etc. That's not a discussion; it's denial. If denial was a valid argument, our nations prisons would be empty because nearly every convict claims. "I didn't do it."

I never said "finite distance over an infinitesimal time..." If that is your perception of what was discussed, then it is a good justification to say that this has not been properly discussed.

So tell me: given how you have defined your system (the Russian Myth), how does your conveyor detect a change in wheel speed in order for the conveyor to react to it? The subsequent reaction is assumed to be instantaneous, but there must first be a condition to react to. What is that condition?
NoCleverName
QUOTE (Sithdarth+Mar 23 2011, 04:30 PM)
3) My theory, and it isn't really a theory since we know Newtonian mechanics works and we know I applied it properly, perfectly explains both experiments. I told you before if you want to make the sort of quantitative comparisons you are trying to make you need a much more sophisticated experimental setup. I can almost guarantee that your acceleration in each run is roughly the same and then you level out to a constant speed that is different for different runs. Actually more likely you start of with a high acceleration that gradually tapers off as you go. There is also probably a good deal of rolling resistance that needs to be accounted for that is occurring at the bearings. Of course since you won't share any of your experimental data, the video, I can't actually help you find the flaw for sure.

Actually, your experiment validates MY theory. I showed the ramp speed was not a factor so long as exceeded a minimum (gravity) and did not exceed a maximum (an acceleration that induced slipping).

Your experiment is merely a confirming data point.

While I could laboriously analyze the data frame-by-frame checking all sorts of numbers (I ran it using a marked sheet against a gridded background) I don't really see the point. All you'll do is argue this and that about the experimental errors (which there are) but that won't change the basic conclusions. I'm sure I pull a paper no more or less precisely than you. Since I have actual time, distance, and angle measurements (of which I provided two cases) and you have NOTHING I'd say the onus is on YOU to make better experiments.

Mine invalidated your theory. Yours did not support your theory TO THE EXCLUSION OF OTHER THEORIES.

Subduction Zone
RTS, sithdaarth does not just deny your silly claims. He has shown both links and formulas that shut you down. You are the one in denial since you are the one who ignores these. After a point all he needs to do is to remind you that all of your nonsense has been dealt with in the past and you had no valid response to it.
NoCleverName
QUOTE (RTS-Eng+Mar 23 2011, 04:51 PM)
how does your conveyor detect a change in wheel speed in order for the conveyor to react to it? The subsequent reaction is assumed to be instantaneous, but there must first be a condition to react to. What is that condition?

... and better yet, how does it KNOW just HOW MUCH to react. You've given a formula that defines how much acceleration to use to counter a given force from the plane. How does the system get the data in order to compute what acceleration to use ... from the many it has to chose from. And how, if you must give the system time to react, do you prevent the ensuing feedback loop that MUST result since the plane now has non-zero velocity. And since the plane DID move forward (if you give the system time to react) how does this not demand the answer "THE PLANE MOVES FORWARD"?

Are we supposed to accept more "magic" from you?
Sithdarth
QUOTE
Your so-called "effect" is merely a coincidence of the math that the speeds of both the belt and the wheels have to be the same for the object to be held in place.

Nope. Newtonian Mechanics works plane and simple.

QUOTE (->
 QUOTE Your so-called "effect" is merely a coincidence of the math that the speeds of both the belt and the wheels have to be the same for the object to be held in place.

Nope. Newtonian Mechanics works plane and simple.

Do you seriously believe that you "predicted" an object could be held in place by a moving ramp?

It is right there in black and white.

QUOTE
3) When the acceleration is beyond that needed to just balance gravity, a torque is developed at the support point against the COM of the object, thus spinning it faster. Of course, new "support points" are supplied again ... just in time ... to keep the object from progressing down the ramp.

There is always a torque thus the increased angular velocity of the wheel. In the case of acceleration beyond that needed to balance gravity new support points are supplied faster than they are needed to keep the object from progressing down the ramp.

QUOTE (->
 QUOTE 3) When the acceleration is beyond that needed to just balance gravity, a torque is developed at the support point against the COM of the object, thus spinning it faster. Of course, new "support points" are supplied again ... just in time ... to keep the object from progressing down the ramp.

There is always a torque thus the increased angular velocity of the wheel. In the case of acceleration beyond that needed to balance gravity new support points are supplied faster than they are needed to keep the object from progressing down the ramp.

... and better yet, how does it KNOW just HOW MUCH to react.

If wheel speed does not equal belt speed the belt knows it didn't react enough.

QUOTE
You've given a formula that defines how much acceleration to use to counter a given force from the plane. How does the system get the data in order to compute what acceleration to use ... from the many it has to chose from.

If wheel speed does not equal belt speed the belt knows its acceleration is wrong.

QUOTE (->
 QUOTE You've given a formula that defines how much acceleration to use to counter a given force from the plane. How does the system get the data in order to compute what acceleration to use ... from the many it has to chose from.

If wheel speed does not equal belt speed the belt knows its acceleration is wrong.

And how, if you must give the system time to react, do you prevent the ensuing feedback loop that MUST result since the plane now has non-zero velocity.

There is no feed back loop. The belt can reduce the wheel speed by accelerating more than is needed to simply cancel the thrust of the plane.

QUOTE
And since the plane DID move forward (if you give the system time to react) how does this not demand the answer "THE PLANE MOVES FORWARD"?

The belt can reduce the wheel speed by accelerating more than is needed to simply cancel the thrust of the plane. You yourself commented on this effect when you noted that even after giving the cart a head start on your ramp you could still stop its forward motion.

QUOTE (->
 QUOTE And since the plane DID move forward (if you give the system time to react) how does this not demand the answer "THE PLANE MOVES FORWARD"?

The belt can reduce the wheel speed by accelerating more than is needed to simply cancel the thrust of the plane. You yourself commented on this effect when you noted that even after giving the cart a head start on your ramp you could still stop its forward motion.

Are we supposed to accept more "magic" from you?

Only if Newtonian Mechanics is considered magic now.
----------------------------------------------------

QUOTE
No we haven't been over it. Your only responses have been "No"..."Wrong"...etc. That's not a discussion; it's denial. If denial was a valid argument, our nations prisons would be empty because nearly every convict claims. "I didn't do it."

Yes we have. I see you like lying as well as eating your foot.

We have this post. Specifically this part:

QUOTE (->
 QUOTE No we haven't been over it. Your only responses have been "No"..."Wrong"...etc. That's not a discussion; it's denial. If denial was a valid argument, our nations prisons would be empty because nearly every convict claims. "I didn't do it."

Yes we have. I see you like lying as well as eating your foot.

We have this post. Specifically this part:

Of course this entire post is irrelevant because you have constructed a strawman argument that has essentially no relation to the actual point I just made. Specifically that Newtonian mechanics is deterministic and a general solution applies to any subset of said general solution. In other words any solution to said subset must agree exactly with the general solution if it does not then it is wrong. Given this and the fact that there are no infinitesimal divisions in the general solution we know that there can be none in any specific solution unless they cancel out. This is the very basics of how science advances. It is because of this that we can build on the work that has come before. If this was not true we would have to rederive every result of physics every time we wanted to prove something new which is absurd.

Which is a very thorough explanation of why you are wrong.

Here is an entire post dedicated to it.

More here.

Another one.

And another.

And another.

This one is a bit short but there are still explanations.

In fact, I have never once replied with nothing but the word "No" or "Wrong" etc to this particular point of yours. Not a single time. Not only is that far from "Your only responses have been "No"..."Wrong"...etc." it is in fact the exact opposite. In fact "Your only responses have been "No"..."Wrong"...etc." is clearly a lie. I think it would be best for you to leave until you can learn to be honest.

QUOTE
I never said "finite distance over an infinitesimal time..." If that is your perception of what was discussed, then it is a good justification to say that this has not been properly discussed.

That is what must happen in order for there to be movement of the plane when speeds match instantaneously. This all boils down to you attempting to apply your physical intuition to things that are not physical.

QUOTE (->
 QUOTE I never said "finite distance over an infinitesimal time..." If that is your perception of what was discussed, then it is a good justification to say that this has not been properly discussed.

That is what must happen in order for there to be movement of the plane when speeds match instantaneously. This all boils down to you attempting to apply your physical intuition to things that are not physical.

So tell me: given how you have defined your system (the Russian Myth), how does your conveyor detect a change in wheel speed in order for the conveyor to react to it? The subsequent reaction is assumed to be instantaneous, but there must first be a condition to react to. What is that condition?

Not really getting the point of instantaneous reaction are we? If I could react instantaneously to something then my reaction and the thing I was reacting to would happen at the same instant. That is what instantaneously means. The condition the belt reacts to is a change in instantaneous velocity of the wheel and it occurs at the same instant as that change. That is what instantaneous means. You cannot apply traditional notions of causality to instantaneous reactions. We've been over this as well.
NoCleverName
QUOTE (Subduction Zone+Mar 23 2011, 05:15 PM)
RTS, sithdaarth does not just deny your silly claims.  He has shown both links and formulas that shut you down.  You are the one in denial since you are the one who ignores these.  After a point all he needs to do is to remind you that all of your nonsense has been dealt with in the past and you had no valid response to it.

No he hasn't. If you look more carefully at the derivation of his "equations" you come to realize that all he has done is solve for the acceleration of the center of mass of a rolling, non-slipping object where F, R, and I are known. Big f'n deal. It's an ENTIRELY DIFFERENT MATTER to justify how this applies to a stationary rotating object, let alone being a "force" that can be used on another object.

Effectively, he starts with "1 = 1". The fact that you apply the same operations to both sides of "1=1" so as to disguise it doesn't change that you started with "1=1". Here we start with "the wheel has no lateral motion". There are loads of theories you could come up with that describe "the wheel has no lateral motion". I've got one, too. It turns out that BOTH theories happen to MATCH at "the wheel has no lateral motion".

The problem lies when you plug into his equations values for accelerations that AREN'T the values for "the wheel as no motion". The theory fails miserably when you don't put in the "right" number. It DOESN'T predict what happens then. If the mechanics were actually right then it WOULD predict what happened with other accelerations.

(And by that i mean experimentally ... sure his equations show "numbers" but they don't bear out when you put it to the physical test).
NoCleverName
QUOTE (Sithdarth+Mar 23 2011, 05:21 PM)
If wheel speed does not equal belt speed the belt knows its acceleration is wrong.

Right ... and the plane is long gone before it ever figures out what speed it has to use.

You really haven't thought this trough very far, have you?

Oh, I forgot ... more "magic" systems.
RTS-Eng
QUOTE (Subduction Zone+Mar 23 2011, 04:15 PM)
RTS, sithdaarth does not just deny your silly claims.  He has shown both links and formulas that shut you down.  You are the one in denial since you are the one who ignores these.  After a point all he needs to do is to remind you that all of your nonsense has been dealt with in the past and you had no valid response to it.

Whoa there little buckaroo. Show me one citation that refutes this. It has never been discussed nor refuted. As I have already pointed out (with quotes of the specific passages) his very own citations acknowledge what I have stated as a failure of the system, not as a support of it.

If it has been discussed as thoroughly as the two of you claim, it should be a piece of cake to quote those passages from either your postings or your citations.

That notwithstanding, answer the simple question: How does your conveyor detect a change in wheel speed in order to react to it?
NoCleverName
I'd even give him a pass on that one because it's sort of secondary. But the fact he can't see that ANY motion, no matter how slight, puts the system as defined into a feedback loop makes it very suspect about what he CAN understand.
RTS-Eng
QUOTE (NoCleverName+Mar 23 2011, 04:15 PM)
And since the plane DID move forward (if you give the system time to react) how does this not demand the answer "THE PLANE MOVES FORWARD"?

Just FYI, but I am not claiming the plane moves forward due to a "reaction time". I am assuming an instantaneous reaction time. The plane must still move forward even with an instantaneous feedback.
NoCleverName
QUOTE (Subduction Zone+Mar 23 2011, 05:15 PM)
RTS, sithdaarth does not just deny your silly claims. He has shown both links and formulas that shut you down. You are the one in denial since you are the one who ignores these. After a point all he needs to do is to remind you that all of your nonsense has been dealt with in the past and you had no valid response to it.

The fact that he can find sources backing up the physics he is using does NOT mean he's using the RIGHT physics.
Sithdarth
QUOTE
No he hasn't. If you look more carefully at the derivation of his "equations" you come to realize that all he has done is solve for the acceleration of the center of mass of a rolling, non-slipping object where F, R, and I are known. Big f'n deal. It's an ENTIRELY DIFFERENT MATTER to justify how this applies to a stationary rotating object, let alone being a "force" that can be used on another object.

No it isn't any different. The equations I started with are completely general. They apply to anything that rolls without slipping. Be it moving or stationary relative to an observer.

QUOTE (->
 QUOTE No he hasn't. If you look more carefully at the derivation of his "equations" you come to realize that all he has done is solve for the acceleration of the center of mass of a rolling, non-slipping object where F, R, and I are known. Big f'n deal. It's an ENTIRELY DIFFERENT MATTER to justify how this applies to a stationary rotating object, let alone being a "force" that can be used on another object.

No it isn't any different. The equations I started with are completely general. They apply to anything that rolls without slipping. Be it moving or stationary relative to an observer.

Effectively, he starts with "1 = 1". The fact that you apply the same operations to both sides of "1=1" so as to disguise it doesn't change that you started with "1=1". Here we start with "the wheel has no lateral motion".

No we don't. That doesn't even come in until much much later.

QUOTE
There are loads of theories you could come up with that describe "the wheel has no lateral motion". I've got one, too. It turns out that BOTH theories happen to MATCH at "the wheel has no lateral motion".

But only one correct one.

QUOTE (->
 QUOTE There are loads of theories you could come up with that describe "the wheel has no lateral motion". I've got one, too. It turns out that BOTH theories happen to MATCH at "the wheel has no lateral motion".

But only one correct one.

The problem lies when you plug into his equations values for accelerations that AREN'T the values for "the wheel as no motion".

That would depend on where you do that. You can't do that at the end because this step:

QUOTE
and X_plane = R*Θ - X_belt, V_plane = R*ω - V_belt, and A_p = R*α - A_belt

but X_belt in this case must be R*Θ (but A_p = R*α - A_belt still holds so A_belt = R*α). So:

X_plane = 0, V_plane = 0, and A_p = 0

Specifically restricts us to the case where the center of mass of the wheel has no motion. If you want other cases you must go back to here:

QUOTE (->
 QUOTE and X_plane = R*Θ - X_belt, V_plane = R*ω - V_belt, and A_p = R*α - A_beltbut X_belt in this case must be R*Θ (but A_p = R*α - A_belt still holds so A_belt = R*α). So:X_plane = 0, V_plane = 0, and A_p = 0

Specifically restricts us to the case where the center of mass of the wheel has no motion. If you want other cases you must go back to here:

M_p*A_p = F_thrust - F_belt = F_thrust - I*α/R

QUOTE
The theory fails miserably when you don't put in the "right" number. It DOESN'T predict what happens then.

Oh gee you mean the theory fails when you specifically plug in numbers that violates one of the assumptions that went into deriving it? You might as well say Special Relativity fails because it doesn't work for speeds greater than the speed of light. If you go back to this point:

QUOTE (->
 QUOTE The theory fails miserably when you don't put in the "right" number. It DOESN'T predict what happens then.

Oh gee you mean the theory fails when you specifically plug in numbers that violates one of the assumptions that went into deriving it? You might as well say Special Relativity fails because it doesn't work for speeds greater than the speed of light. If you go back to this point:

M_p*A_p = F_thrust - F_belt = F_thrust - I*α/R

Everything will work fine.

Oh and you'll need this:

QUOTE
A_p = R*α - A_belt

QUOTE (->
 QUOTE A_p = R*α - A_belt

If the mechanics were actually right then it WOULD predict what happened with other accelerations.

It does if you do the math right.

QUOTE
Right ... and the plane is long gone before it ever figures out what speed it has to use.

Prove it.

QUOTE (->
 QUOTE Right ... and the plane is long gone before it ever figures out what speed it has to use.

Prove it.

You really haven't thought this trough very far, have you?

Oh you mean like finding a MOUNTAIN OF EVIDENCE, doing out the math for three different cases, and doing an experiment to confirm? But no I haven't thought this through very far at all.

QUOTE
I'd even give him a pass on that one because it's sort of secondary. But the fact he can't see that ANY motion, no matter how slight, puts the system as defined into a feedback loop makes it very suspect about what he CAN understand.

IT DOESN'T

QUOTE (->
 QUOTE I'd even give him a pass on that one because it's sort of secondary. But the fact he can't see that ANY motion, no matter how slight, puts the system as defined into a feedback loop makes it very suspect about what he CAN understand.

IT DOESN'T

The fact that he can find sources backing up the physics he is using does NOT mean he's using the RIGHT physics.

Right. Sources such as physics text books and people that have credibility in terms of being right are obviously not right.

I mean really just because I find a source that says the world is round doesn't mean the world is round or anything.
-------------------------------------------------------------
QUOTE
Whoa there little buckaroo. Show me one citation that refutes this. It has never been discussed nor refuted. As I have already pointed out (with quotes of the specific passages) his very own citations acknowledge what I have stated as a failure of the system, not as a support of it.

More lies.

QUOTE (->
 QUOTE Whoa there little buckaroo. Show me one citation that refutes this. It has never been discussed nor refuted. As I have already pointed out (with quotes of the specific passages) his very own citations acknowledge what I have stated as a failure of the system, not as a support of it.

More lies.

If it has been discussed as thoroughly as the two of you claim, it should be a piece of cake to quote those passages from either your postings or your citations.

Oh you mean like I did not two posts above this post of yours?

QUOTE
That notwithstanding, answer the simple question: How does your conveyor detect a change in wheel speed in order to react to it?

QUOTE (->
 QUOTE That notwithstanding, answer the simple question: How does your conveyor detect a change in wheel speed in order to react to it?

Just FYI, but I am not claiming the plane moves forward due to a "reaction time". I am assuming an instantaneous reaction time. The plane must still move forward even with an instantaneous feedback.

Physically impossible.
RTS-Eng
QUOTE (Sithdarth+Mar 23 2011, 05:02 PM)
QUOTE

That notwithstanding, answer the simple question: How does your conveyor detect a change in wheel speed in order to react to it?

If it is such a simple answer, then it should be easier to answer the question than it is to sidestep it (which I believe is what you like to call a strawman argument).

Answer the question: How does your conveyor detect a change in wheel speed in order to react to it?
NoCleverName
Feedback loop:

The plane is moving at 1mph over the belt as seen by the outside observer.

The belt sees the wheel moving at 1mph and adjusts its speed to 1 mph.

The plane is still moving over the belt at 1 mph ... but now the belt is going 1 mph.

The wheels speed is now a combined 2 mph so the belt adjusts its speed to 2 mph.

The plane is still going 1 mph over the belt ... but now the belt is going 2 mph.

The wheel speed is now a combined 3 mph so the belt adjusts its speed to 3 mph

The plane is still going 1 mph over a belt that is moving at 3 mph.

This could go on for a while ...

Sithdarth
QUOTE

QUOTE (->
 QUOTE If it was already addressed, then please provide the citation...something more in-depth than you saying, "Wrong".

Not really getting the point of instantaneous reaction are we? If I could react instantaneously to something then my reaction and the thing I was reacting to would happen at the same instant. That is what instantaneously means. The condition the belt reacts to is a change in instantaneous velocity of the wheel and it occurs at the same instant as that change. That is what instantaneous means. You cannot apply traditional notions of causality to instantaneous reactions. We've been over this as well.

QUOTE
If it is such a simple answer, then it should be easier to answer the question than it is to sidestep it (which I believe is what you like to call a strawman argument).

Except where I haven't done that.

QUOTE (->
 QUOTE If it is such a simple answer, then it should be easier to answer the question than it is to sidestep it (which I believe is what you like to call a strawman argument).

Except where I haven't done that.

Answer the question: How does your conveyor detect a change in wheel speed in order to react to it?

QUOTE
Not really getting the point of instantaneous reaction are we? If I could react instantaneously to something then my reaction and the thing I was reacting to would happen at the same instant. That is what instantaneously means. The condition the belt reacts to is a change in instantaneous velocity of the wheel and it occurs at the same instant as that change. That is what instantaneous means. You cannot apply traditional notions of causality to instantaneous reactions. We've been over this as well.

--------------------------------------------------

QUOTE (->
 QUOTE Not really getting the point of instantaneous reaction are we? If I could react instantaneously to something then my reaction and the thing I was reacting to would happen at the same instant. That is what instantaneously means. The condition the belt reacts to is a change in instantaneous velocity of the wheel and it occurs at the same instant as that change. That is what instantaneous means. You cannot apply traditional notions of causality to instantaneous reactions. We've been over this as well.

--------------------------------------------------

Feedback loop:

The plane is moving at 1mph thru space as seen by the outside observer.

The belt sees the wheels moving at 1mph and adjusts its speed to 1 mph.

So far so good.

QUOTE
The plane is still moving thru space at 1 mph ... but now over a belt that is also going 1 mph.

Whoops made a mistake. This depends entirely on how fast the belt adjusted its speed to 1 mph. In other words it depends on the acceleration of the belt.

QUOTE (->
 QUOTE The plane is still moving thru space at 1 mph ... but now over a belt that is also going 1 mph.

Whoops made a mistake. This depends entirely on how fast the belt adjusted its speed to 1 mph. In other words it depends on the acceleration of the belt.

The wheels speed is now a combined 2 mph so the belt adjusts its speed to 2 mph.

False since it follows from the false premise above.

QUOTE
The plans is still going 1 mph thru space ... but now the belt is going 2 mph.

See the point about how the acceleration of the belt effects the speed of the plane. A fact we have already established.

QUOTE (->
 QUOTE The plans is still going 1 mph thru space ... but now the belt is going 2 mph.

See the point about how the acceleration of the belt effects the speed of the plane. A fact we have already established.

The wheel speed is now a combined 3 mph so the belt adjusts its speed to 3 mph

Again follows from a false premise and therefore is false.

QUOTE
The plane is still going 1 mph thru space over a belt that is moving at 3 mph.

See the point about how the acceleration of the belt effects the speed of the plane. A fact we have already established.

QUOTE (->
 QUOTE The plane is still going 1 mph thru space over a belt that is moving at 3 mph.

See the point about how the acceleration of the belt effects the speed of the plane. A fact we have already established.

This could go on for a while ...

Only by ignoring that the belt cannot accelerate without changing the speed of the plane.
NoCleverName
Gotta love ya, Darth ... you simply DEFINE your answer to be right!

You are so hopelessly outclassed by your "answer" the "Feedback loop" I won't embarrass you any further about it. Besides, it's not germane to your theory, anyway.
Sithdarth
QUOTE
Gotta love ya, Darth ... you simply DEFINE your answer to be right!

Nope.

QUOTE (->
 QUOTE Gotta love ya, Darth ... you simply DEFINE your answer to be right!

Nope.

You are so hopelessly outclassed by your "answer" the "Feedback loop" I won't embarrass you any further about it. Besides, it's not germane to your theory, anyway.

If you can in anyway refute anything I said then do it. If not admit you are wrong so we can move on. Otherwise this is not a debate and we can stop right here.

It's very simple. In order for the belt to change velocities it must accelerate. If the belt accelerates it changes the velocity of the center of mass of the plane which effects the tire speed.
NoCleverName
No, you'll never do it ... let's just run thru one cycle.

Let's use big numbers to keep this simple with the proviso that you can choose numbers "arbitrarily small" and it won't affect the outcome. Let's even give your system "foreknowledge" that it will have to face 1000 newtons force and to do that it has precomputed it'll need acceleration of 100 m/s/s.

Say the control system checks the wheels speed every 1 second. At time t=0 the wheel is at rest. But all of a sudden at scan time t=1 it sees the plane moving at 1 m/s. So it accelerates to 1 m/s at 100 m/s/s which takes 1/100 second.

It then stops accelerating. Why? Because of the rules ... the wheel speed was 1 m/s so it can't go faster than 1 m/s.

But in this 1.01 seconds the planes engines delivered an impulse f 1000*1.01 newton*seconds. Your system, on the other hand, since it reached full speed in 0.01 seconds and was constrained to 1000 newtons force delivered only 1000 * 0.01 newton*seconds.

I think you start to see the problem here.
Sithdarth
QUOTE
No, you'll never do it ... let's just run thru one cycle.

Let's use big numbers to keep this simple with the proviso that you can choose numbers "arbitrarily small" and it won't affect the outcome. Let's even give your system "foreknowledge" that it will have to face 1000 newtons force and to do that it has precomputed it'll need acceleration of 100 m/s/s.

Say the control system checks the wheels speed every 1 second. At time t=0 the wheel is at rest. But all of a sudden at scan time t=1 it sees the plane moving at 1 m/s. So it accelerates to 1 m/s at 100 m/s/s which takes 1/100 second.

It then stops accelerating. Why? Because of the rules ... the wheel speed was 1 m/s so it can't go faster than 1 m/s.

But in this 1.01 seconds the planes engines delivered an impulse f 1000*1.01 newton*seconds. Your system, on the other hand, since it reached full speed in 0.01 seconds and was constrained to 1000 newtons force delivered only 1000 * 0.01 newton*seconds.

You shouldn't have stopped there. In that .01 seconds the plane hasn't accelerated at all. The belt since it knows it has to maintain an acceleration of 100 m/s^2 to keep the plane from accelerating will maintain this acceleration for the next .99 seconds until the second speed check at t = 2. At which point it will see that the wheel speed still isn't equal to the belt speed. Thus it will know that it needs to accelerate faster and it will then accelerate faster. This would be why I said this:

QUOTE (->
 QUOTE No, you'll never do it ... let's just run thru one cycle.Let's use big numbers to keep this simple with the proviso that you can choose numbers "arbitrarily small" and it won't affect the outcome. Let's even give your system "foreknowledge" that it will have to face 1000 newtons force and to do that it has precomputed it'll need acceleration of 100 m/s/s.Say the control system checks the wheels speed every 1 second. At time t=0 the wheel is at rest. But all of a sudden at scan time t=1 it sees the plane moving at 1 m/s. So it accelerates to 1 m/s at 100 m/s/s which takes 1/100 second.It then stops accelerating. Why? Because of the rules ... the wheel speed was 1 m/s so it can't go faster than 1 m/s.But in this 1.01 seconds the planes engines delivered an impulse f 1000*1.01 newton*seconds. Your system, on the other hand, since it reached full speed in 0.01 seconds and was constrained to 1000 newtons force delivered only 1000 * 0.01 newton*seconds.

You shouldn't have stopped there. In that .01 seconds the plane hasn't accelerated at all. The belt since it knows it has to maintain an acceleration of 100 m/s^2 to keep the plane from accelerating will maintain this acceleration for the next .99 seconds until the second speed check at t = 2. At which point it will see that the wheel speed still isn't equal to the belt speed. Thus it will know that it needs to accelerate faster and it will then accelerate faster. This would be why I said this:

Therefore once the acceleration that matches the thrust is achieved and since the thrust of the plane is essentially constant the plane will no longer accelerate with respect to the ground. From there getting belt speed and wheel speed to match is simply a matter of accelerating the belt a little bit extra for a little extra time. That is as long as we aren't allowing instant reactions.

Of course 1 second is a horribly long time to go between speed samplings. In general one would schedule the checks to occur in less time than the acceleration would take. Every millisecond or even less.
NoCleverName
QUOTE (Sithdarth+Mar 23 2011, 07:11 PM)

You shouldn't have stopped there. In that .01 seconds the plane hasn't accelerated at all. The belt since it knows it has to maintain an acceleration of 100 m/s^2 to keep the plane from accelerating will maintain this acceleration for the next .99 seconds until the second speed check at t = 2. At which point it will see that the wheel speed still isn't equal to the belt speed. Thus it will know that it needs to accelerate faster and it will then accelerate faster. This would be why I said this:

Cheating. The belt can't exceed the wheel speed. The wheel speed was 1 m/s at the time check. The system isn't allowed to make the wheel go any faster just because it can. You are allowed only your acceleration to stop the plane ... you said that's all it would take.

You can choose a speed only at every time check because of the rules ... exceeding the speed limit breaks the rules.

I told you before your plan would work ... if it actually had a physical basis and it doesn't ... ONLY at "equilibrium" and that you failed to account for system start up. This also shows that the feedback loop, as described, would occur BECAUSE YOU FAILED TO STOP THE WHEEL INSTANTANEOUSLY.

When you rev'ed up the belt to 1 m/s yourself, you caused the wheel speed to increase to 2 m/s. But the plane is still moving at 1 m/s so now at the next time check you accelerate to 2 m/s in .02 seconds. Even if you successfully stopped the plane from accelerating it still has constant speed ... which gets added to the wheel speed, which gets added to the belt speed, etc. etc.

The feedback loop occurs. But that's just an aside. Unless you cheat, the system as you have it set up can't stop the plane ... and that's even with foreknowledge of what it has to do.
Sithdarth
QUOTE
Cheating. The belt can't exceed the wheel speed.

It never does.

QUOTE (->
 QUOTE Cheating. The belt can't exceed the wheel speed.

It never does.

The wheel speed was 1 m/s at the time check. The system isn't allowed to make the wheel go any faster just because it can.

This isn't happening.

QUOTE
You are allowed only your acceleration to stop the plane ... you said that's all it would take.

WHY DO I HAVE TO REPEAT MYSELF TEN TIMES EVERY TIME I MAKE A SIMPLE POINT?

QUOTE (->
 QUOTE You are allowed only your acceleration to stop the plane ... you said that's all it would take.

WHY DO I HAVE TO REPEAT MYSELF TEN TIMES EVERY TIME I MAKE A SIMPLE POINT?

Therefore once the acceleration that matches the thrust is achieved and since the thrust of the plane is essentially constant the plane will no longer accelerate with respect to the ground. From there getting belt speed and wheel speed to match is simply a matter of accelerating the belt a little bit extra for a little extra time. That is as long as we aren't allowing instant reactions.

You can read, you've demonstrated at least that much ability. There is no reason for this. There is no explanation except that it is on purpose. STOP doing it now or cease to participate in this discussion.

In case you don't get the point I'm driving at:

The only time it only takes just the one acceleration is the specific case of instantaneous reaction time. Once you consider real engineering problems like reaction time big surprise it takes a real engineering solution. I am writing this big so that you can read it.

QUOTE
You can choose a speed only at every time check because of the rules ... exceeding the speed limit breaks the rules.

1) That's bull and absolutely the stupidest way to engineer this system. Of course in the limit of instantaneous reactions this does in fact work just fine.

2) I never once exceeded the speed that the wheels where actually turning at. I exceeded the speed at the time check but a properly designed belt system knows that the wheel and plane are accelerating and knows that this must be taken into account. It would be about the stupidest thing in creation to not take this into account.

QUOTE (->
 QUOTE You can choose a speed only at every time check because of the rules ... exceeding the speed limit breaks the rules.

1) That's bull and absolutely the stupidest way to engineer this system. Of course in the limit of instantaneous reactions this does in fact work just fine.

2) I never once exceeded the speed that the wheels where actually turning at. I exceeded the speed at the time check but a properly designed belt system knows that the wheel and plane are accelerating and knows that this must be taken into account. It would be about the stupidest thing in creation to not take this into account.

I told you before your plan would work ... if it actually had a physical basis and it doesn't ... ONLY at "equilibrium" and that you failed to account for system start up. This also shows that the feedback loop, as described, would occur BECAUSE YOU FAILED TO STOP THE WHEEL INSTANTANEOUSLY.

Wrong for all the reasons above.

QUOTE
When you rev'ed up the belt to 1 m/s yourself, you caused the wheel speed to increase to 2 m/s.

No I didn't. That assumes plane speed is constant when the belt accelerates to 1 m/s. This we know is not true. I've already said this do not make me repeat it again.

QUOTE (->
 QUOTE When you rev'ed up the belt to 1 m/s yourself, you caused the wheel speed to increase to 2 m/s.

No I didn't. That assumes plane speed is constant when the belt accelerates to 1 m/s. This we know is not true. I've already said this do not make me repeat it again.

But the plane is still moving at 1 m/s so now at the next time check you accelerate to 2 m/s in .02 seconds.

This is exactly the same error you made before and it has exactly the same solution. If you aren't even going to take the time to read and understand my points then you should leave now!

QUOTE
Even if you successfully stopped the plane from accelerating it still has constant speed ... which gets added to the wheel speed, which gets added to the belt speed, etc. etc.

Wrong. It gets added once and that is all and the belt seeing that there is always a constant difference knows it needs to accelerate more quickly. By accelerating more quickly this constant difference is reduced but the belt never at any instant exceeds the speed of the wheels.

QUOTE (->
 QUOTE Even if you successfully stopped the plane from accelerating it still has constant speed ... which gets added to the wheel speed, which gets added to the belt speed, etc. etc.

Wrong. It gets added once and that is all and the belt seeing that there is always a constant difference knows it needs to accelerate more quickly. By accelerating more quickly this constant difference is reduced but the belt never at any instant exceeds the speed of the wheels.

The feedback loop occurs. But that's just an aside. Unless you cheat, the system as you have it set up can't stop the plane ... and that's even with foreknowledge of what it has to do.

Wrong. Absolutely positively wrong because of all the reasons above. You know what I'm done with you. I'm done repeating things TWENTY GODDAMNED TIMES to you. You've lost I've won. That is it. You no longer have any points to make. Accept the answer or not you are wrong I am right. This is no longer a discussion and you have no more right to be a part of any further discussion.
NoCleverName
Nope, you've designed your system around cheating.

But, Darth, forget that friggin control system. Why hang your reputation on that piece of junk? I could care less about it.

That just takes us off the situation with your theory, which also doesn't work. When are you going to do some experiments that stand scrutiny? Until then, it's all misapplied math to me.
Sithdarth
QUOTE
Nope, you've designed your system around cheating.

Didn't.

QUOTE (->
 QUOTE Nope, you've designed your system around cheating.

Didn't.

But, Darth, forget that friggin control system. Why hang your reputation on that piece of junk? I could care less about it.

Then you shouldn't have even brought it up.

QUOTE
That just takes us off the situation with your theory, which also doesn't work. When are you going to do some experiments that stand scrutiny? Until then, it's all misapplied math to me.

1) The theory works.

2) I did do an experiment that demonstrated exactly what I said it would.

3) Your inability to understand the math does not make it misapplied. It makes you wrong.

4) We are no longer having this discussion. In fact I should have stopped the instant you said this:

QUOTE (->
 QUOTE That just takes us off the situation with your theory, which also doesn't work. When are you going to do some experiments that stand scrutiny? Until then, it's all misapplied math to me.

1) The theory works.

2) I did do an experiment that demonstrated exactly what I said it would.

3) Your inability to understand the math does not make it misapplied. It makes you wrong.

4) We are no longer having this discussion. In fact I should have stopped the instant you said this:

The fact that he can find sources backing up the physics he is using does NOT mean he's using the RIGHT physics.

This is a clear indication that you will not accept what is otherwise perfectly acceptable proof to any other reasonable human. Therefore you are not open to actual debate. Therefore there is no reason to debate you at all. Since you will not accept evidence then there is no point presenting you with evidence.
NoCleverName
Oh, I just brought it up to see how stubbornly you'd defend a clearly losing position. Sort of to gauge what kind of person I'm dealing with. I'll keep my conclusions to myself.

I will give you credit for capability. I don't even mind your passionate defense of your position. By the way, yelling has no affect on me ... I've seen too much over too long a time to care about someone screaming in my direction.

For a while there I was going to acknowledge you might have a good theory -- in some regimes --- until I looked at the edges. When I looked at all the off-axis cases is when the red flags started coming up. So for now, your theory is just a coincidence at the inflection point as far as I'm concerned.
Subduction Zone
It looks like NCN is going into full Black Knight mode. Both legs and arms cut off and he is declaring victory.
NoCleverName
QUOTE (Subduction Zone+Mar 23 2011, 09:28 PM)
It looks like NCN is going into full Black Knight mode. Both legs and arms cut off and he is declaring victory.

On the contrary, it is more accurate to say that "I remain unconvinced". I have been presented with nothing but troubling pronouncements.
RTS-Eng
QUOTE (Sithdarth+Mar 23 2011, 05:27 PM)
QUOTE
Not really getting the point of instantaneous reaction are we? If I could react instantaneously to something then my reaction and the thing I was reacting to would happen at the same instant. That is what instantaneously means. The condition the belt reacts to is a change in instantaneous velocity of the wheel and it occurs at the same instant as that change. That is what instantaneous means. You cannot apply traditional notions of causality to instantaneous reactions. We've been over this as well.

So we are both in agreement that a change in velocity (Δv) is required for the conveyor to react. Correct?

The conveyor must see some change in velocity before it can set a new velocity, correct?
NoCleverName
Boy, you're on a losing mission, engineer. He's not going to give up "anticipatory response" from that control system. This is a point he CAN'T concede because, if accepted, then neither his nor any other response can prevent feedback, or in the alternative, motion of the plane.

So, the only worthwhile value to arguing about the control system is just to expose his obstinance.

His theory, however, bears more scrutiny. It seems very vulnerable to attack due to lack of symmetry. I can't figure, for example, why the belt is "preferred" and always moves while the plane can't stop the belt. After all, the plane pushing on the wheel reverses things in a couple of ways (not just direction, for one) but now the contact point is the center of rotation and the axle essentially rotates around it. I've seen the moment of inertia calculated from this perspective and it comes out the same as the "normal" way, so why isn't the effect symmetric?

Not withstanding the experimental results, which seem more easily explained by a much simpler model.
Subduction Zone
NCN, don't take any solace from RTS' last post. It only shows that he does not understand the mathematical concept of a limit. Again this is part of the reason for sithdarth's exasperation. He has dealt with this misunderstanding of RTS's before.

You do realize that you both claim that the belt could not keep the plane in place for different reasons I hope? His problem is that he wants to take it out of the realm of a thought problem, and then he runs away when we tell him we can deal with it as a partial engineering problem. You don't seem to understand how the belt can apply a force to a wheel. At least RTS understands that much. He is wrong on a higher level than you are wrong.
Derek1148
QUOTE (Sithdarth+Mar 23 2011, 11:54 PM)
The only time it only takes just the one acceleration is the specific case of instantaneous reaction time. Once you consider real engineering problems like reaction time big surprise it takes a real engineering solution. I am writing this big so that you can read it.

Instantly is kind of a subjective term. Any time one instantly reacts, by definition it would be slightly slower than the action which preceded the instantaneous reaction. Simultaneously is more scientific.
RTS-Eng
QUOTE (Subduction Zone+Mar 23 2011, 09:25 PM)
NCN, don't take any solace from RTS' last post. It only shows that he does not understand the mathematical concept of a limit.

Where did limits suddenly come from? Nothing about my discussion implied or even suggested limits. You simply threw that in without basis. Correct me if I am wrong, but isn't that the very definition of a strawman argument that the two of you keep spewing as reason to not discuss the problem?

Stick to the discussion at hand. Refute the information at hand. The questions asked have not been answered.
Subduction Zone
QUOTE (RTS-Eng+Mar 24 2011, 03:17 AM)
Where did limits suddenly come from? Nothing about my discussion implied or even suggested limits. You simply threw that in without basis. Correct me if I am wrong, but isn't that the very definition of a strawman argument that the two of you keep spewing as reason to not discuss the problem?

Stick to the discussion at hand. Refute the information at hand. The questions asked have not been answered.

Nope, not a straw man argument. You have shown your ignorance about limits and how they apply to this problem by your misunderstanding the concept of simultaneity.

We have kept to the subject at hand, all of your arguments have been refuted.

Here, let me ask you the question either NCN or synthin ignored. The wheels speed change from 9 mph to 10 mph. Does the treadmill react sometime tomorrow?
NoCleverName
Maybe you should have read my example more closely.

The control system needs a way of determining the wheel speed (this is the engineer's fight with Darth ... Darth won't allow for any time dt in which to measure the wheel speed). I propose dispensing with that argument and just letting the control system strobe the data at regular intervals. I showed that even with system reaction times far faster than the strobe rate, the system is still unstable. Worse yet, I showed that the belt doesn't have enough time to deliver enough countering energy (assuming this were even possible) because the fast reaction time actually cuts off the countering energy supply too soon.

Darth countered with "once it's on, leave it on". Leaving aside for a moment that this strategy puts the system into feedback, the strategy has no guarantee of stopping the plane before it takes off ... unless the system has foreknowledge about the plane's performance characteristics.

For example, the plane might be moving ahead initially at 1 m/s ... but since this could be a 1000 kg plane with 1000 newton engines or a 10,000 kg plane with 10,000 newton engines, the system doesn't know if it needs (say) 100 m/s/s acceleration or 1000 m/s/s acceleration because it doesn't know initially how much force to counter. After the first strobe cycle it should be able to determine what it's dealing with. But now we get into the hazy area of "what are the rules". Does the system get to match the wheels speed it measured or is it allowed to just run up the speed to anything it wants? If the former, the system can't stop the plane but it is behaving more in the spirit of the rules. If the later, the system is just brute force applying the "theory" without regard to any rule.

In any event, since the plane has already got SOME forward velocity the system has to add more acceleration than the initial calculation suggested.

The whole control system argument basically is about, "if this effect really existed, could a CONCEPTUALLY PRACTICAL system implement it". Depending on how much you wanted to violate the rules, the answer would range between "probably not" and "maybe, but not right away".

Of course, I reside firmly in the camp that the effect is a pipe dream based on misapplied physics.
RTS-Eng
QUOTE (Subduction Zone+Mar 23 2011, 10:26 PM)
Here, let me ask you the question either NCN or synthin ignored.  The wheels speed change from 9 mph to 10 mph. Does the treadmill react sometime tomorrow?

I am not refuting instantaneous reaction. I have repeatedly said that my argument is not based on the reaction time of the system. It has been assumed to be instantaneous.

How does your conveyor detect a change in wheel speed in order to react to it?
NoCleverName
QUOTE (RTS-Eng+Mar 23 2011, 11:53 PM)
I am not refuting instantaneous reaction. I have repeatedly said that my argument is not based on the reaction time of the system. It has been assumed to be instantaneous.

Even more telling, what is the target wheel speed the system is shooting for? The one it measured (somehow) or some other speed (how is THAT chosen)?
Derek1148
QUOTE (RTS-Eng+Mar 24 2011, 03:53 AM)
How does your conveyor detect a change in wheel speed in order to react to it?

That is my point. Since whole thing is imaginary, why not have the conveyor change speed simultaneously with wheel speed?
NoCleverName
QUOTE (Derek1148+Mar 24 2011, 12:00 AM)
That is my point.  Since whole thing is imaginary, why not have the conveyor change speed simultaneously with wheel speed?

But to WHAT wheel speed?
Derek1148
QUOTE (NoCleverName+Mar 24 2011, 04:01 AM)
But to WHAT wheel speed?

Whatever you want it to be. It's all imaginary.
NoCleverName
QUOTE (Derek1148+Mar 24 2011, 12:03 AM)
Whatever you want it to be. It's all imaginary.

OK, but that devolves into a brand new myth: both sides have complete knowledge of the others performance capabilities. We just rev up the plane and the belt, release the brakes, and let them go at it. Forget the dysfunctional control system.
RTS-Eng
QUOTE (Derek1148+Mar 23 2011, 11:00 PM)
That is my point. Since whole thing is imaginary, why not have the conveyor change speed simultaneously with wheel speed?

Because the conveyor belt was not defined to be anticipatory. It was defined only to react to the speed of the wheel.
Subduction Zone
QUOTE (RTS-Eng+Mar 24 2011, 03:53 AM)
I am not refuting instantaneous reaction. I have repeatedly said that my argument is not based on the reaction time of the system. It has been assumed to be instantaneous.

How does your conveyor detect a change in wheel speed in order to react to it?

Fine. If the reaction is instantaneous then there will be no motion relative to the ground. There will be motion relative to the belt. You need to remember that the instantaneous reaction means that the forces on the plane will always balance.

What did Newton tell you happens when the forces balance on an object?

ETA: If you ask how you are entering into the realm of an engineering problem. The answer in the thought problem is "I don't know, and I don't care, it just does". Now if you want to discuss this as an engineering problem we are fine with that too.
NoCleverName
I'm more than happy to avoid implementation problems.

The bigger problem is the statement "the forces balance". They don't because the wheels can't transmit a force thru to the plane via acceleration alone.

(well, aside from trivial rolling friction)
RTS-Eng
QUOTE (Subduction Zone+Mar 23 2011, 11:12 PM)
Fine.  If the reaction is instantaneous then there will be no motion relative  to the ground.  There will be motion relative to the belt.  You need to remember that the instantaneous reaction means that the forces on the plane will always balance.

What did Newton tell you happens when the forces balance on an object?

ETA:  If you ask how you are entering into the realm of an engineering problem.  The answer in the thought problem is "I don't know, and I don't care, it just does".  Now if you want to discuss this as an engineering problem we are fine with that too.

The forces balancing is a conclusion, not a definition. Nevertheless, it still doesn't answer the question. This is NOT an "engineering" question, nor is it an "instantaneous" question. It is a question regarding the mathematical definition of your conveyor.

Your conveyor was defined for the steady state. How does the conveyor detect a change in wheel speed in order to react to it?
Subduction Zone
RTS, this is an engineering question:
QUOTE
How does the conveyor detect a change in wheel speed in order to react to it?

We don't care how, it does. It is a thought problem deal with it. Once again, if you want to enter the realm of dealing with this as an engineering problem we are fine with that as well. We will do so. But as long as you are in denial there is no point in doing so.

NCN, all I can say is wrong. If you don't agree with sithdarth you need to get some math or physics to support you. So far you have offered nothing.
Derek1148
QUOTE (Subduction Zone+Mar 24 2011, 05:20 AM)
...if you want to enter the realm of dealing with this as an engineering problem we are fine with that as well.

Wouldn't an engineer consider the physics involved?
RTS-Eng
QUOTE (Subduction Zone+Mar 24 2011, 12:20 AM)
RTS, this is an engineering question:

We don't care how, it does.

It is not an engineering question. You're taking it too literal. It is a mathematical question. What is the mathematical expression that introduces acceleration into your system, given the definition of your system?
Subduction Zone
QUOTE (RTS-Eng+Mar 24 2011, 05:30 AM)
It is not an engineering question. You're taking it too literal. It is a mathematical question. What is the mathematical expression that introduces acceleration into your system, given the definition of your system?

It is time for you to get into a shorter river. It is a thought problem, you have to take it literally.

Wait, you want the mathematical expression? That's easy. Vbelt = Vwheels, By definition, if Vbelt increase so does Vwheels. Next.
Subduction Zone
QUOTE (Derek1148+Mar 24 2011, 05:30 AM)
Wouldn't an engineer consider the physics involved?

He has considered some of the physics involved. That is why he understands how the belt can place a force on the wheels that opposes the plane's forward motion, unlike NCN. We are now nitpicking about how it senses the speed of the wheels.
RTS-Eng
QUOTE (Subduction Zone+Mar 24 2011, 12:34 AM)
By definition, if Vbelt increase so does Vwheels. Next.

Oops! Your slip is showing (r. Dear Abby). v_belt cannot increase until v_wheel increases.
Derek1148
QUOTE (Subduction Zone+Mar 24 2011, 05:37 AM)
He has considered some of the physics involved.  That is why he understands how the belt can place a force on the wheels that opposes the plane's forward motion, unlike NCN.  We are now nitpicking about how it senses the speed of the wheels.

But you're not talking about force. You're talking about speed. The speed of the conveyor. Is that enough to stop the forward motion of the plane? Would a wheel driven vehicle react the same as an air thrusted vehicle?
Subduction Zone
QUOTE (RTS-Eng+Mar 24 2011, 05:38 AM)
Oops! Your slip is showing (r. Dear Abby). v_belt cannot increase until v_wheel increases.

Still in denial, don't worry, so is NCN.

When you get out and want to discuss this as an engineering problem I am happy to do so. Here is a hint: A simultaneous increase in velocity means that both velocities would increase at the same time. Neither occurs "first".
Subduction Zone
QUOTE (Derek1148+Mar 24 2011, 05:47 AM)
But you're not talking about force. You're talking about speed. The speed of the conveyor. Is that enough to stop the forward motion of the plane? Would a wheel driven vehicle react the same as an air thrusted vehicle?

The force on the wheel is a result of the consequences of matching the speed. If you want to debate you really should follow along. You need to check out sithdarth's equations that tell you why there is a force on the wheels.

To answer your second question, no, a wheel driven vehicle would be stopped much easier. But its speed to would be the same as the conveyor belt. Wheel driven vehicles usually have an upper limit on the speed of its wheels. That is how fast the belt would go to hold it in place. Since, ideally, the forces of friction and rolling resistance are constant the belt would have to accelerate at a constant rate to keep a plane in place.

I hope you do know the difference between velocity and acceleration.
Derek1148
QUOTE (Subduction Zone+Mar 24 2011, 06:12 AM)
If you want to debate you really should follow along.

Since, ideally, the forces of friction and rolling resistance are constant the belt would have to accelerate at a constant rate to keep a plane in place.

Hey, I've got to work for al living. I might have missed a few posts.

Suppose the plane doesn't accelerate at a constant rate or maintain a constant velocity. Wouldn't it all be variable?
RTS-Eng
QUOTE (Subduction Zone+Mar 24 2011, 01:03 AM)
Still in denial, don't worry, so is NCN.

When you get  out and want to discuss this as an engineering problem I am happy to do so.  Here is a hint:  A simultaneous increase in velocity means that both velocities would increase at the same time.  Neither occurs "first".

It's not denial. It's cause and effect. You wouldn't suggest that acceleration causes gravity, would you? However, gravity causes acceleration. (That's hyperbole, by the way. So there is no need for Sithdarth to try to argue the point.)

Your conveyor was defined to be active-reactive: it reacts to the wheel speed and supplies power. However, the wheel is defined to be passive-active: it cannot supply power, but it is the source of the feedback. When you put these two together, you get a system that cannot start, nor accelerate.

It is the equivalent error that "perpetual motion" proponents make in their arguments. Would you like to be lumped in with them? (That's hyperbole too, by the way...and just in case sithdarth doesn't realize it yet, hyperbole is not a mathematical formula.)
Sithdarth
I presented evidence. No one else has presented evidence. My conclusion is correct. Anyone that disagrees is wrong. RTS-Eng is doubly wrong for being a malicious cowardly liar. Do not engage him. He will immediately resort to insulting you, creating strawman arguments, and out right lies when backed into a corner. He will not debate and he will not ever admit to being wrong about anything. He is precisely as bad as CT or perpetual motion nut.
Lasand
While this doesn't prove either side, it is more to the point than the battery video.

Subduction Zone
QUOTE (Lasand+Mar 24 2011, 02:31 PM)
While this doesn't prove either side, it is more to the point than the battery video.

Sorry, it is not. No one disputes the Physics For Dummies version that the OP of this thread posted. We are discussing the original version of this thought problem. Your video shows a plane taking off with its wheel speed greater than the treadmill speed. It does not apply to this argument.
Derek1148
QUOTE (Subduction Zone+Mar 24 2011, 03:45 PM)
Sorry, it is not. No one disputes the Physics For Dummies version that the OP of this thread posted. We are discussing the original version of this thought problem. Your video shows a plane taking off with its wheel speed greater than the treadmill speed. It does not apply to this argument.

In reference to the research on the atomic bomb by the Manhattan Project: "The bomb will never go off. I speak as an expert in explosives." - Admiral William Leahy (to President Truman)
Subduction Zone
QUOTE (Derek1148+Mar 24 2011, 04:13 PM)
In reference to the research on the atomic bomb by the Manhattan Project: "The bomb will never go off. I speak as an expert in explosives." - Admiral William Leahy (to President Truman)

Did you see the video in question, or even read my post? Probably not. Reading comprehension seems to be rather high in the deniers camp. One more time, that video was an illustration of the version that was posted by the OP. No one here is denying that the plane would take off with that version of the question. The answer is trivially easy. The question we are discussing is the original version where the speed of the belt matches the speed of the wheels. You should not need this reminder. But if you cannot understand this distinction I can see why you don't understand how the belt will hold the plane in place.
Derek1148
QUOTE (Subduction Zone+Mar 24 2011, 04:22 PM)
But if you cannot understand this distinction I can see why you don't understand how the belt will hold the plane in place.

The only "place" the belt holds the plane in place, is in your mind.
Subduction Zone
It is too bad that you and your ilk cannot understand the concept of a thought problem. Insults do not help your side, actual math and physics might.
Lasand
You just shot down your own "proof of concept" video. It doesn't even have a wheel speed. The mountain of evidence is going down to anthill size.

Post the battery/notebook link again. You know, the one where the battery stops rolling due to molecular adhesion from kinetic friction.
Subduction Zone
QUOTE (Lasand+Mar 24 2011, 05:02 PM)
You just shot down your own "proof of concept" video. It doesn't even have a wheel speed. The mountain of evidence is going down to anthill size.

Post the battery/notebook link again. You know, the one where the battery stops rolling due to molecular adhesion from kinetic friction.

That's a good one. Tell me how did I shoot down the proof of concept video.

One question first, did you make it through grade school physics?
Sithdarth
QUOTE
You just shot down your own "proof of concept" video. It doesn't even have a wheel speed. The mountain of evidence is going down to anthill size.

You do realize that we've been using wheel speed to mean the angular velocity times the radius and that anything round that rolls has an identical quantity?

QUOTE (->
 QUOTE You just shot down your own "proof of concept" video. It doesn't even have a wheel speed. The mountain of evidence is going down to anthill size.

You do realize that we've been using wheel speed to mean the angular velocity times the radius and that anything round that rolls has an identical quantity?

Post the battery/notebook link again. You know, the one where the battery stops rolling due to molecular adhesion from kinetic friction.

1) Kinetic friction occurs when two surfaces slide past each other. No such sliding occurred in the video.

2) Kinetic friction and rolling resistance are both independent of velocity for the velocities achieved by the battery. If either one were the explanation the battery would not have rolled down the ramp while it was stationary.

3) The video is significantly less than 1/10 of the evidence I have presented. Even if you had a point, and you don't, it doesn't even dent the case that has been made.

Sithdarth
QUOTE
You just shot down your own "proof of concept" video. It doesn't even have a wheel speed. The mountain of evidence is going down to anthill size.

You do realize that we've been using wheel speed to mean the angular velocity times the radius and that anything round that rolls has an identical quantity?

QUOTE (->
 QUOTE You just shot down your own "proof of concept" video. It doesn't even have a wheel speed. The mountain of evidence is going down to anthill size.

You do realize that we've been using wheel speed to mean the angular velocity times the radius and that anything round that rolls has an identical quantity?

Post the battery/notebook link again. You know, the one where the battery stops rolling due to molecular adhesion from kinetic friction.

1) Kinetic friction occurs when two surfaces slide past each other. No such sliding occurred in the video.

2) Kinetic friction and rolling resistance are both independent of velocity for the velocities achieved by the battery. If either one were the explanation the battery would not have rolled down the ramp while it was stationary.

3) The video is significantly less than 1/10 of the evidence I have presented. Even if you had a point, and you don't, it doesn't even dent the case that has been made.

NoCleverName
In case you were wondering, Lasand, the "mountain of evidence" comprises three "popular" accounts of the plane-on-a-conveyor problem and a handful of textbook references to problems involving weights dropped over a pulley system. Not exactly on point.

And he right that the video is less then 1/10 of the "evidence" since it's not even that convincing.
QUOTE (NoCleverName+Mar 24 2011, 07:02 PM)
In case you were wondering, Lasand, the "mountain of evidence" comprises three "popular" accounts of the plane-on-a-conveyor problem and a handful of textbook references to problems involving weights dropped over a pulley system. Not exactly on point.

And he right that the video is less then 1/10 of the "evidence" since it's not even that convincing.

[SIZE=7] For the third time Noclevername how did you derive the Rolling resistance coefficient for the 777 most of the research I have done is for the 747-400. Off to work again so If you reply I'll catch up with it when I get home. Thanks
RTS-Eng
QUOTE (Sithdarth+Mar 24 2011, 02:17 AM)
I presented evidence. No one else has presented evidence. My conclusion is correct. Anyone that disagrees is wrong.

Yes, you have presented "evidence". However, the scientific community has safeguards in place to prevent faulty evidence from becoming accepted as scientific fact. Part of those safeguards is the review and defense of that evidence. It is not considered scientific fact unless it can survive the review process. Yours has not yet completed the review process, as there are still valid arguments presented.

You've been content to discuss this topic for nearly 200 pages, as long as the arguments have not approached anything resembling a valid argument. To your credit, you've even refuted the same "unfounded" arguments several times. I applaud your patience in this regard.

However, now when a potentially valid argument does comes up, you suddenly throw up your arms and say you won't discuss it. You claim to have discussed this topic before, but you have neither discussed it on this forum, nor have you provided the citations to support that you have previously discussed it elsewhere.

This is a new topic that you have not previously address. Instead, you run away from the discussion before it can even begin. If my assertions are baseless, then it should be quite easy for you to refute them in a scientific manner. That doesn't mean a drive-by answer such as, "wrong". It means a discussion about them and why they are wrong.

Subduction Zone
RTS, if you are referring to the variations you have made on your first claim, then yes it has been dealt with. Just because you don't like an answer does not mean that the debate is still open. You need to come up with an original complaint. Don't keep rehashing an old busted one.
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