Insyght
I was pondering over the thought that infinate energy would be needed to accelerate an object with mass to the speed of light and thought of this mental exercise below which fascinated me.

Supposed you have sphere, say the size of the sun, with two long arms, which are - lets say 1/2 a light year long. The spherical device is able to spin @ half the speed of light before energy requirements become too much to spin any faster.

You attached to the end of one of the arms a ship/probe

you spin the sphere to half of the speed of light.

How fast would the probe be travelling? would it reach/even exceed the speed of light?

Assumptions: Ultra strong, rigid material for the arms which would not bend (Impossible I know). The sphere has enough energy to spin to half speed of light, carrying the arms with it (Impossible I know).

What do you think would happen?
Daein
I think that space would twist in this case. There are two satilites in orbit now to test this theory since it's unconfirmed.
Christoph
so, this sun is half the diameter of the arms? seems unnecesary. it's just a question of rotating any object (bar, sphere, sun, a chevy) such that the outermost point reaches C. what i immediately thought of was a motor and flywheel travelling through space near the speed of light. plausible. then you spin up the flywheel, and try to break the speed of light with the resultant velocity vector of the flywheel's edge, which would be following a helical path.
solidspin
unfortunately, C for an object whose deBroglie wavelength (lambda = h/p) is too large will never be reached w/o driving the mass of the object to infinity - all due to Einstein's SR. It won't matter whether you're in space or in Iowa.

Ck out Ronald Mallett's paper on rotational hv, however. His idea does apparently not conflict theoretically.

http://www.csmonitor.com/2002/0516/p12s02-stss.html

Good Elf
Hi Insyght,

QUOTE
You attached to the end of one of the arms a ship/probe

you spin the sphere to half of the speed of light.

How fast would the probe be traveling? would it reach/even exceed the speed of light?

Assumptions: Ultra strong, rigid material for the arms which would not bend (Impossible I know). The sphere has enough energy to spin to half speed of light, carrying the arms with it (Impossible I know).

What do you think would happen?

You said that you are spinning it at only 1/2 the speed of light. Well thats all you are going to get. It is your assumption. According to the Special Theory of Relativity and ignoring other GR effects, you would have some apparent length contraction in the direction of motion and none in a direction perpendicular to the direction of motion. The circumference of the "system" will shrink slightly but the radius will not. You will "invalidate" C = 2R where R remains constant but C will be shrinking the faster it goes.

I suppose you realize you are making an interesting sandwich spread out of the occupants of the probe.

Now assume the arms are made from something "impossible" that will not break and you have the energy to "go as fast as you like". It is going to curve spacetime but ignore that for the moment. The circumference will shrink continuously but not the radius as seen from the plane of rotation internally. What you see will depend on your vantage point and where you are viewing from. The tips (probe) cannot move at the speed of light but the circumference can apparently shrink to near zero. Between the center of the system and the tips the "spokes" will be "wound up" at or near the rim (probe). Actually the probe would be apparently "rotated" almost 90 degrees from the direction of progress into a direction perpendicular to all normal orthogonal directions (length contraction seen as spatial rotation). This is in the literature. Seen from the inside it will be smeared into a continuous band (reflecting the almost zero diameter of the external circle of rotation). This will mostly occur within a few centimeters of the rim and the spokes will otherwise appear unaffected.

The (probe) rim will be almost "suspended" in time due to the Clock Paradox. It will have more frequency character than any temporal reference (1/T instead of T character) in that state with de Broglie phenomena predominating. Its dimensions will not be measurable due to optical rotation (length contraction) It will not be locatable via position and momentum simultaneously with any normal observation. The folding of spacetime will occur but it will be far beyond the normal range of "linear algebra" that tensors are based on that maths will not be able to be correctly applied there without some radical revision. Externally... I "imagine" a kind of "dumbbell" effect where the middle waist will appear to be shrunk to nearly zero circumference with an "optical" halo due to the extreme curvature of the surrounding spacetime forming two "spheres" top and bottom distorting what is seen there. An effect not dissimilar from Einstein's Rings.

Interestingly the "lorentzian rotation" seen on the outside will always be away from the direction of motion and the observer... the same as seen from the inside. You could say it is "curled" into higher spaces!!

Cheers
moron
Wow! That is amazing. I'd never thought... no; the only "thought" I'd had in this topic was to wonder once, many years ago, if it would someday be possible to somehow increase the spin on a single electron dramatically, and get _that_ torqued up to lightspeed -- what would happen? I couldn't imagine. Other than to wonder if the experiment wouldn't somehow "tear" a small hole in spacetime -- a wormhole of some kind, perhaps. Who knows? I don't. Would such an experiment even be interesting? How would it be accomplished?
Good Elf
Hi moron and Insyght,

QUOTE
Other than to wonder if the experiment wouldn't somehow "tear" a small hole in spacetime -- a wormhole of some kind, perhaps. Who knows? I don't. Would such an experiment even be interesting? How would it be accomplished?

The "probe" would not be possible to build (so to many it is not "interesting") since any mechanical material structure could not sustain such forces. The radius of the system would shrink to fit the structure and visa versa. If the arms were twice the length it would approach the speed of light much sooner in angular velocity (at lower rotation rate) and length contraction (rotation) would occur there sooner at a greater radius. "Interesting" experiments are contrived to support existing theory not bring it down, this is definitely not an "interesting" place to go since direct measurement will not be possible.

All existing experiment rely on direct measurement. There is another way to proceed but it is harder. For all that it matters it may as well be a rent in spacetime since at that point it will then be no longer possible to do measurements anyway. You are dealing with "Schrodinger's Cat" in a box... not only is it "dead" or is it "alive" but is it licking it paws or watching TV... etc? Quantum Theory does not deal with unobserved phenomena and is a recognized difficulty called the Measurement Problem. All the interesting questions about "what happens next" are taboo to Quantum Theory and have no answers. Do your measurement and you have destroyed the quantum phenomenon. Yet he whole Universe is largely an "unobserved Phenomenon", in our inflated ego we have maintained that nothing occurs without man's personal observation to "collapse" the state of the superimposed systems to one. . A bit much to expect from even ye "gods in the making"! Yet this is the current theory.

The radius of the wheel would remain more or less unchanged again at the larger radius and the problems will only occur close to that radius where once again things would appear to being "wound up". The reason for this apparent compression is the optical effects of approaching the speed of light is highly skewed toward to the last couple of percent of approaching the speed of light and in this system the linear velocity is increasing rapidly for small changes in radius. For the radius inside that last critical percent spacetime will appear relatively normal all the way to the center. Internally increasing the rate of rotation would simply progress the "horizon" down along the arms compressing the tips on to a surface along with the arms. This would follow the velocity of the specific point on the arms that was now approaching the speed of light. At no point would any part of the structure actually reach the speed of light, otherwise it would be a violation of the Special Theory. Stuff that was formerly beyond that point would now appear compressed onto the new "approaching" 2D surface, an optical effect only. It would not be "intelligible" or able to be understood by measurement or observation. It is debatable if you would see anything at all... this phenomena would probably be as invisible as normal quantum events since light will barely be able to progress to or from that region - as I said before it is undergoing "extreme" clock paradox phenomena and for photons to "work" there they need a frequency and this is something they will not have - no time and hence no frequency. I think it will be interaction-less. Events will have "ceased" on this "event horizon".

All these individual effects are able to be calculated "roughly" using Special and General Relativity and by application of be Broglie's Principle and Heisenberg's Uncertainty relationships. Will this operation have quantized spacetime? All attempts to show that it has... have resulted in failure. Quantum Gravity sucks. The attempt goes on to find this granularity, stable states that might be measured. Think about the physical situation and think again.... and again.

The interesting fact is this "probe" would be a physical object that probably does indeed have a position and momentum but is now acting beyond the predictions of Quantum Theory in a space that will not map into a flatspace (3D + T) that Quantum Theory needs for that interpretation since the theory of the Quantum does not have extra dimensions beyond 4. Naturally internally you would begin to see the effects of this General Relativistic Curvature as well. Everything 'falls" apart in this process and only "New Physics" would allow this to be interpreted. I suggest that Special and General Theory alone are capable of handling this process since it already deals with curved spaces and the Quantum Theory does not. Ditch it!

Anybody can comment... with Insyght's permission of course. It is always a good question and it is not engraved in stone. To me it is one of the more important thought experiments in Physics.

Cheers
moron
QUOTE (Good Elf+Jul 31 2005, 02:04 AM)
The "probe" would not be possible to build (so to many it is not "interesting") since any mechanical material structure could not sustain such forces.

Well, no -- of course you're right; manipulating a single electron's spin behaviour with a "probe" made of matter is not possible. But -- what about light? Or some other as-yet-unknown energy field? I wouldn't think it'd be _completely_ impossible... after all; we've barely scratched the thinnest sliver of surface in our meager "discoveries", so far.
xymox
I think using only my common sense and not using any wierd equation, That you could exceed the speed of light, Its my opinion that things routinely travel at speeds greater than C. However we are unable to observe it. If the long outstreatched arms of the rotating sphere were moving faster than the speed of light? how could you tell? We could not observe the result.

I remember a post a while ago about 2 stars each traveling at .6 c in opposite directions. In reality i believe that the perception, by a creature able to see things on a cosmic level, would be more than C, But we as observers on either star would never see the other star retreating. We should be able however to make an educated observation that the net result is 1.2 C between the two stars if were smack dab in the middle.

Can anybody refute this? Please keep an emphasis on what we are able to perceive. No tricky calculations!
solidspin
xymox -

Incorrect on 2 counts. The stars are travelling in opposite directions, so you will not have 1.2©. You will have a redshift, but light doesn't work like that. The redshift will be a function of the distance b/t them, increasing in wavelength proportional to the distance. Oops, you can't handle any "math", so I may have overstepped my bounds.

To prove this, simply go out to Brookhaven National Lab. The physicists can't get the electrons producing x-rays higher than about 0.62©, b/z relativistic effects make the electron mass greater than what the wiggler magnets can handle. The signal degrades. This is a very real experiment, since you can see the degradation. I very much need to get them to get my high-E x-rays to look at my crystals.

Listen, you very much need math and to criticize it as "fancy" just tells me you need to learn a lot more math, and admit when you're ignorant. I admit that I'm ignorant every day, for if I did not, I would cease to learn, as you seem to have done.

-ss
xymox
Well, I admit that I am ignorant of most things. Even tho I have a Bachelors degree in Math. I know very little when you consider all that there is to know.

I am familiar with the pa expiraments and how the faster they travel the bigger they get and all that jazz

What would happen if those 2 stars were connected by a really big bungee cord for instance, so we can forget about photons for a second. There is litterally mass connecting the 2, and should have nothing to do with the speed of light, how fast, or at what rate, I should say, would the cord be streaching?

kikiki62
QUOTE (Insyght+Jul 29 2005, 02:40 PM)
I was pondering over the thought that infinate energy would be needed to accelerate an object with mass to the speed of light and thought of this mental exercise below which fascinated me.

Supposed you have sphere, say the size of the sun, with two long arms, which are - lets say 1/2 a light year long. The spherical device is able to spin @ half the speed of light before energy requirements become too much to spin any faster.

You attached to the end of one of the arms a ship/probe

you spin the sphere to half of the speed of light.

How fast would the probe be travelling? would it reach/even exceed the speed of light?

Assumptions: Ultra strong, rigid material for the arms which would not bend (Impossible I know). The sphere has enough energy to spin to half speed of light, carrying the arms with it (Impossible I know).

What do you think would happen?

light speed can be exceeded if u want to know more i can show u how it is done serious inquiry only!!!!
krash661
QUOTE (kikiki62+May 19 2012, 06:13 AM)
light speed can be exceeded if u want to know more i can show u how it is done serious inquiry only!!!!

I'm interested.
kikiki62
QUOTE (krash661+May 19 2012, 04:57 PM)
I'm interested.

here is how it is done u need a radiometer,next u will need a laser beam mounted on a revolving motor like a helicopter blade the laser is mounted at the ends of the shaft and thus spun at different rpms and the radiometer is measured with another laser rpm speed detector and u will see the rpms will rise as the shaft turns faster.Einstein said light is not affected by an objects speed,make this experiment for your self and u will see he was wrong.
flyingbuttressman
QUOTE (kikiki62+May 21 2012, 11:15 AM)
here is how it is done u need a radiometer,next u will need a laser beam mounted on a revolving motor like a helicopter blade the laser is mounted at the ends of the shaft and thus spun at different rpms and the radiometer is measured with another laser rpm speed detector and u will see the rpms will rise as the shaft turns faster.Einstein said light is not affected by an objects speed,make this experiment for your self and u will see he was wrong.

Have you personally conducted this experiment?
AlexG
QUOTE (kikiki62+May 21 2012, 10:15 AM)
here is how it is done u need a radiometer,next u will need a laser beam mounted on a revolving motor like a helicopter blade the laser is mounted at the ends of the shaft and thus spun at different rpms and the radiometer is measured with another laser rpm speed detector and u will see the rpms will rise as the shaft turns faster.Einstein said light is not affected by an objects speed,make this experiment for your self and u will see he was wrong.

A simple piece of nonsense.

So as the shaft turns faster, the shaft turns faster. So what? In what way is c exceeded?
kikiki62
QUOTE (flyingbuttressman+May 21 2012, 05:07 PM)
Have you personally conducted this experiment?

Of course!!!! I have talked with many scientist if they new of any experiment that could do such a thing,(Without revealing my intentions ) they (all) said it was a useless
endeavor to even think that was possible!!! mind you it is a precise experiment that leaves nothing for error!!!!
flyingbuttressman
QUOTE (kikiki62+May 21 2012, 02:46 PM)
Of course!!!! I have talked with many scientist if they new of any experiment that could do such a thing,(Without revealing my intentions ) they (all) said it was a useless
endeavor to even think that was possible!!! mind you it is a precise experiment that leaves nothing for error!!!!

You do realize that there is no such thing as a "laser rpm speed detector" right?
AlexG
This certainly has the smell of garbage which has sat for a week or two.
kikiki62
QUOTE (flyingbuttressman+May 21 2012, 08:53 PM)

You do realize that there is no such thing as a "laser rpm speed detector" right?

I see I am talking with ignorance,had your chance!!!! Gone for good!!!
flyingbuttressman
QUOTE (kikiki62+May 21 2012, 11:28 PM)
I see I am talking with ignorance,had your chance!!!! Gone for good!!!

hpdrdoom
If an object exceeds the speed of light then it would be invisible and if it is "not in vacuum" then the object will burn out due to friction caused by the particles around it.

Though no particle other than photons can go faster than light because basically photons have no mass at all.
Quantum_Conundrum
QUOTE (hpdrdoom+Jun 5 2012, 09:05 AM)
If an object exceeds the speed of light then it would be invisible and if it is "not in vacuum" then the object will burn out due to friction caused by the particles around it.

Though no particle other than photons can go faster than light because basically photons have no mass at all.

No, not true.

If an object could somehow exceed the speed of light, it is not necessarily invisible anyway. Suppose some Quantum effect somehow allows a particle to "jump" the limit at v equals c...

Suppose it is radiating infrared energy, then that would be detectable...just because the object moved away doesn't mean light or other EM radiation moving back towards the viewer would never reach you. The only exception to that is the hypothetical "Light Horizon" at the edge of the universe, caused by space-time itself expanding at the speed of light.

But for "proper motion" you are wrong.

If you could somehow get an object above the speed of light, it should still produce radiation visible to viewers behind it, there would just be extremely freaky delays in each successive photon's arrival to the viewer.
Blu3dud3
Im Very interested in this. And to see how this works.

Also As i might have mis-understood earlyer.

You were using a Bike peddle lets say how it turns a tire using different variations of Gears ( in different Diameters )

So if you where to get the peddles moving at nearly the speed of light wouldn't the Gears ( Rotating the tire ) Be moving faster then the Peddles pushing the bike?

I know there is no way that we have anything strong enough to test this theory and the forces apply'd to the gears or the peddles.

Maybe i mis-understood something in the texts before but wouldnt it be plausible?
LaurieAG
QUOTE (flyingbuttressman+May 22 2012, 06:53 AM)
You do realize that there is no such thing as a "laser rpm speed detector" right?

Hi flyingbuttressman,

I have one of these and it just uses a LED combined with an optical sensor to send out consistent pulses and count how many times those pulses rebound off the rotor blades. No sign of any FTL travel though.

http://www.hobbyking.com/hobbyking/store/_...PM_Sensor_.html

QUOTE
FrSky RPMS-01 Telemetry RPM Sensor
RPM sensor reads RPM data by using an optical sensor.

Measurement Range: 0~60000r/min
Installation: Point the RPM sensor straight up at any accessory that requires RPM reading.
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