Ewol
I think I am right in saying that if a ball is thrown upwards then when it comes down its terminal velocity when it hits the ground should be the same as its initial velocity when it left, assuming no other forces act on it such as friction with the air.

If this is right that initial and terminal velocities are the same in a gravitational field then it follows that at an event horizon around a black hole where escape velocity = speed of light then any terminal velocity of something entering it must be the same. Therefore the surface of a black hole must lie at or just within the event horizon (no singularity). If it was say 1/2 the distance between the center and the EH then the gravitational pull at the surface would be the equivalent of 4 x SoL (inverse square) as the SoL cannot be exceeded then there must be a maximum value gravity can reach and that is at an EH and so there must be a maximum density matter can reach such as that within a BH so how can the matter in the universe be compressed further to the BB singularity?

Secondly is it possible that all the forces could be unified within the extreems of a BH. How would something like the strong force behave if all particles were compressed to the point where they effectively became a single particle i.e absolutely no room for movement for any individual particles Quarks, electrons etc what so ever within the larger mass.

Someone will now tell me that you cannot describe gravitational fields in terms of escape and terminal velocity, so if you like to work out the gravitational field at an EH in mts/s/s and again for a distance 1/2 way between the center and the EH and determine how fast the terminal velocities would be for an object falling in I would be interested to know if it works out any differently.
Robittybob1
QUOTE (Ewol+Oct 28 2011, 03:39 PM)
I think I am right in saying that if a ball is thrown upwards then when it comes down its terminal velocity when it hits the ground should be the same as its initial velocity when it left, assuming no other forces act on it such as friction with the air.

If this is right that initial and terminal velocities are the same in a gravitational field then it follows that at an event horizon around a black hole where escape velocity = speed of light then any terminal velocity of something entering it must be the same. Therefore the surface of a black hole must lie at or just within the event horizon (no singularity). If it was say 1/2 the distance between the center and the EH then the gravitational pull at the surface would be the equivalent of 4 x SoL (inverse square) as the SoL cannot be exceeded then there must be a maximum value gravity can reach and that is at an EH and so there must be a maximum density matter can reach such as that within a BH so how can the matter in the universe be compressed further to the BB singularity?

Secondly is it possible that all the forces could be unified within the extreems of a BH. How would something like the strong force behave if all particles were compressed to the point where they effectively became a single particle i.e absolutely no room for movement for any individual particles Quarks, electrons etc what so ever within the larger mass.

Someone will now tell me that you cannot describe gravitational fields in terms of escape and terminal velocity, so if you like to work out the gravitational field at an EH in mts/s/s and again for a distance 1/2 way between the center and the EH and determine how fast the terminal velocities would be for an object falling in I would be interested to know if it works out any differently.

They are very good questions but I would say keep posting your own solutions to these questions for there are very few here actively posting on this forum.
I'll see if we can find the answer to the questions as well.
boit
Unfortunately there is no quick answers. One has to learn college physics before attempting to comprehend all this. Lessons unfortunately aren't cheap.
Why Not?
Terminal velocity is the maximum speed a given object can achieve when moving through a given medium. As such, to say "assuming no other forces act on it such as friction with the air" makes no sense within the description given. I think the term you are looking for is "Free Fall". Try starting here: http://en.wikipedia.org/wiki/Free_fall It's always good to start by leaning some good old Newtonian physics...
Ewol
Yes Free Fall is what I meant.

The point I was thinking of, if not already worked out, is as the speed of light cannot be exceeded then a body in free fall cannot be accelerated beyond this by a gravitational field such as in a Black Hole. This potentially means that gravity has a maximum value, as gravity is normally related to mass this means that gravity is not caused by mass alone as once the maximum is reached adding mass will not increase the gravitational field which is what all the equations relating to gravity say should happen, presumably adding mass using current equations will just push gravity to higher and higher levels.

The question with Black Holes is where is the surface, I believe it lies at that point where an object in free fall reaches the speed of light which would seem to be the event horizon.

If this is right would it alter any current understanding about gravity and/or black holes.
Why Not?
You're on the right track but it is more complicated than simply saying, "the surface of a black hole is it's event horizon" because the "surface" is relative to the position of the observer. Leonard Susskind has proposed Black Hole Complementarity to deal with this very issue.
Ewol
Have read the BH complimentary but it is different to my idea.

There is no singularity to fall into and you cannot fall through the event horizon the same way you cannot fall through the earths surface. The curvature of spacetime reaches its maximum at the event horizon.

Assuming my concept of information is correct anything falling into a BH will eventually end up as its most fundamental form of sub atomic particles which will just add to the mass of the BH much like adding balls to a childs ball pond where the balls represent electrons, Quarks etc. So information will be inaccessible not lost.

What happens to any energy associated with matter falling in. I dont see how it can remain as energy so is it converted to particles or does it somehow radiate away. I take it kinetic energy cannot be converted to gravitational energy and so radiate away as gravity.

Not sure what you mean by the surface is relative to the position of the observer.

As a matter of interest I keep reading about a difference in gravity when worked out in relativity and newtonian. Would I be right in thinking that einstinian has a slightly higher value than newtonian?
Why Not?
Part of the problem is that your idea is incorrect. I suggest you do some research into blackhole physics and work on understanding the concepts of gravity and general relativity. http://en.wikipedia.org/wiki/Black_hole And then read through some of the 100 or so references at the end of the of the page.

Also, they call it "relativity" for a reason... http://en.wikipedia.org/wiki/Principle_of_relativity

Ewol
Unfortunately in all the information on Black Holes there is nothing to suggest that Gravity may reach a maximum value. All mention singularities at the center where gravity becomes infinite.

The question remains can gravitational attraction reach the point where an object in free fall exceeds the speed of light. If so then the speed of light constant is incorrect, making a big hole in relativity, if not then gravity must have a maximum value making at least some of Black Hole theory incorrect.

I am unable to find any comparisons between einstein and newton regarding gravitational attraction. Is the orbit of mercury explained because relativity shows a higher or lower value for gravity or is there no way to compare the different way they reach thier conclusions.

Why Not?
QUOTE
The question remains can gravitational attraction reach the point where an object in free fall exceeds the speed of light.

Unequivocally this question has been answered and that answer is no. Special relativity explains why. It is impossible to accelerate an object of mass to the speed of light. Look at the subsection - Upper Limits on Speed on this page http://en.wikipedia.org/wiki/Speed-of-light.

QUOTE (->
 QUOTE The question remains can gravitational attraction reach the point where an object in free fall exceeds the speed of light.

Unequivocally this question has been answered and that answer is no. Special relativity explains why. It is impossible to accelerate an object of mass to the speed of light. Look at the subsection - Upper Limits on Speed on this page http://en.wikipedia.org/wiki/Speed-of-light.

I am unable to find any comparisons between einstein and newton regarding gravitational attraction. Is the orbit of mercury explained because relativity shows a higher or lower value for gravity or is there no way to compare the different way they reach thier conclusions.

You can't compare the two in the way that you are trying to compare the two. Newton found the Universal Gravitational Constant, G, which works well in non-relativistic gravity calculations. But it does not work so well in relativistic gravity calculation. Einstein, in formulating General Relativity, showed gravity could better be described as the curvature of four dimensional spacetime.

In relatively flat spacetime, General Relativity reduces to Newtonian gravity. But in high gravitational fields, Newtonian gravity breaks down - shows errors between observation and calculation. General Relativity better deals with high gravitational fields. Thus, the GR calculation of Mercury matches the observations.

QUOTE
if not then gravity must have a maximum value making at least some of Black Hole theory incorrect.

"Gravity" does not have a maximum value, but spacetime curvature does, that is why General Relativity predicts a singularity at the center of a black hole. Black hole theory is far from complete. Because the maths say there should be a singularity at the center of a black hole means on of two things, 1) there is a singularity at the center of a black hole, or 2) there are is new physics yet to be discovered. And there are lots of people working on number 2.

Robittybob1
QUOTE (Ewol+Nov 3 2011, 10:13 AM)
Unfortunately in all the information on Black Holes there is nothing to suggest that Gravity may reach a maximum value. All mention singularities at the center where gravity becomes infinite.

The question remains can gravitational attraction reach the point where an object in free fall exceeds the speed of light. If so then the speed of light constant is incorrect, making a big hole in relativity, if not then gravity must have a maximum value making at least some of Black Hole theory incorrect.

I am unable to find any comparisons between Einstein and newton regarding gravitational attraction. Is the orbit of mercury explained because relativity shows a higher or lower value for gravity or is there no way to compare the different way they reach their conclusions.

What do you do Ewol? You have some strong views on this topic, so where do they come from?
Ewol
I'm just someone with an interest in puzzles one of which is the way the universe works. I've been doing a lot of reading over the last year or so and trying to make sense of things, or work out the underlying reasons why things are as they are. I may ask at lot of what may seem silly questions but you only get to the right one by eliminating the wrong ones and I am sure that not all the questions have been asked even about things we think we know, hence things like extra dimensions. I could accept a twin universe theory though.
Unfortunately I have no-one with the knowledge to discuss things with and have to resort to sites such as this to get questions answered which makes things even more difficult.

Take gravity and relativity for example, the classic example is the rubber sheet one but while ok in 2 dimensions it makes no sense in 3 dimensions and even in 2d the earth does not orbit the top of the sun but the middle. If you use 2 objects with the same mass they will just sit in their own depressions. I can see the curvature of spacetime and its effects caused by gravity but not as the cause of gravity.

Then there is time dilation, speed = distance/time but at c d and t = 0 which gives us for an object moving at c c=0/0. I can see that if you are moving at the same speed as somthing else then relative speed = 0 but if time stops relative to the rest of the universe then that is another matter you get left behind relatively speaking, I do realise it has been proven but it still leaves the underlying question as to why the universe works in such a way.

I think there is a relationship between gravity and energy with the extreems being the speed of light and an event horizon but how do you express them in the same units. There must be a reason why G is what it is, I thought perhaps it was related to density but apparently not. The universe must work within finite mathematical boundaries but where are they.

There is the last answer given by whynot an excellent answer but it does not explain how or why newton breaks down in high gravitational fields, perhaps if the distance between the shwartzchild radii was use rather than the actual centers it would make a difference but would it be in the right direction?

I do not like the idea of singularities, if you start at the EH of a Black Hole and work inwards halving the radius each time gravitational force will go up and up and must reach the point where an object in free fall would exceed the speed of light which takes us back to my last post. but you will never reach a singularity at 0. But a BH can be any size independant of its mass but dependant on its density which leads us to -

The density of a sub atomic particle, if an electron as a particle has no internal structure it must be as dense as or very near to the matter found in a BH. So if it was possible could 2 electrons in reality be squeezed into the volume occupied by 1? Why does an electron not vanish into a BH, I suspect it is something to do with its wave/particle nature.

The 2nd law of thermodynamics and the cup falling on the floor example is another one. The cup has been artificialy organised and is just trying to get back to its origional state. To me it should say that all things will try to reach their lowest stable energy state, heavy sub atomic particles decay into lower energy particles, heavy elements decay into lighter stable ones and large stars are less stable than smaller ones burning out more quickly.

There is more but I'll see how we get on with the above.

niels
QUOTE (Ewol+Oct 28 2011, 03:39 PM)
I think I am right in saying that if a ball is thrown upwards then when it comes down its terminal velocity when it hits the ground should be the same as its initial velocity when it left, assuming no other forces act on it such as friction with the air.

If this is right that initial and terminal velocities are the same in a gravitational field then it follows that at an event horizon around a black hole where escape velocity = speed of light then any terminal velocity of something entering it must be the same. Therefore the surface of a black hole must lie at or just within the event horizon (no singularity). If it was say 1/2 the distance between the center and the EH then the gravitational pull at the surface would be the equivalent of 4 x SoL (inverse square) as the SoL cannot be exceeded then there must be a maximum value gravity can reach and that is at an EH and so there must be a maximum density matter can reach such as that within a BH so how can the matter in the universe be compressed further to the BB singularity?

Secondly is it possible that all the forces could be unified within the extreems of a BH. How would something like the strong force behave if all particles were compressed to the point where they effectively became a single particle i.e absolutely no room for movement for any individual particles Quarks, electrons etc what so ever within the larger mass.

Someone will now tell me that you cannot describe gravitational fields in terms of escape and terminal velocity, so if you like to work out the gravitational field at an EH in mts/s/s and again for a distance 1/2 way between the center and the EH and determine how fast the terminal velocities would be for an object falling in I would be interested to know if it works out any differently.

IMO you address some of the fundamental questions that I have been pondering about.

Matter - energy etc is IMO fundamentally a derived function of observer and therefore of anthropic character (nothing new in this) - however IMO the anthropic part is often ignored or neglected.

And this brings me to the definition of PHYSDICAL as being intimately bound to the concept of DIMENSION - how to establish a 3D metric, because IMO physical is something being perceived as a dymanically changing "3D wholeness". The question is "what is changing - and how someting can change" - in other words how to understand "WHAT" and "HOW".

In order for me to get a better understanding the best idea leading to least paradoxes in its out-folding, is the idea of "Large Extra Dimensions" - actually not only large but a number of dimensions that approaches true infinite - without ever reaching infinite.

IMO - PHYSICAL is being fundamentally of FINITE character. "Perceiving takes discretions".

This implicate that spacetime (noumenal world) is being made of something that cannot be zero or nothing. It means that physical requires a metaphor that is not zero - and at the same time being the most fundamental (not simple !) metaphor that is required in order to describe and define a dynamically changing wholeness.

This implicate that space-time can be seen as something being composed of such objects of sameness organized in ever diluting scales like a Russian Doll structure, where each scale can be seen as a 3D grid, where points in one scale can be seen as another 3D grid structure in the next following scale - and how the playing of points in a 3D grid structure in one scale defines or express wavefunctions, that is seen as points in the next following scale.

Change is effected via reconfigurations of such signaling points (on off) and a signal involve a kind of movement - but such a movement is the result of re-configurations of smaller points in lower scale - ad infinitum - so the concept of movement is expressed via reconfiguratin of patterns - so movement will always be relative to a scale. Similar for existence of points - will always be relative to a repetitive pattern in a said scale. This is what explains HOW and WHAT.

And then the question WHY - why do points in the grid reconfigure. My idea is that "Universe strives after best fit - strives after obtaining least free void". Imagine how such points is positioned shoulder by shoulder - they will strive after getting best fit (according to their shape) to their neighbors - and once a point has changed its position then one of the neighbors will get the "least better fit" and such adjustments will spread domino-like over the grid - introducing a wave like the rising arm showing the"wave" by the public in an arena.

Photon is wave-patterns played by the 3D grid in the scale below physical scale, and provided that these waves enter into repetition - we get particle expression in our physical scale. The threshold for human sensing is photon /electron. A black hole can be seen as a volume of space-time where the playing of the 3D grid is suppressed, because every point (pixel) in such a pixel grid has a mute period after having signalled, and provided that there is too many signals coming from all directions in the grid, and with high intensity, the result will be a BH that cannot translate information into the next following scale.

The event horizon is equivalent to the radius of the mute area of the 3Dgrid and depending on the variation of incoming wave-functions (equivalent to how matter in universe fluctuate and organize) any black hole will absorb or evaporate information. Everything is being related to scales and the relative position of observer.

Real physical is one specific scale of space-time - being observed by similar stuff in the same scale (human Qbit) who can be seen as a fairly unstable repetitive pattern lasting about 100 years and with the ability of self-sensing - self perceiving the surrounding information. The result is a time-capsule like observation where human mind integrate space-time interferences with surrounding universal space-time so as to create this vivid impression of a"real physical world" dynamically changing.

Universe or space-time does not show any movement - except when being integrated as flash-pattern expressions by human mind, and this is a process giving rise to time-quants - the period constructed by human mind when integrating flashes in order to put together a movie-strip that can be perceived as "something". The longer the period of integration (observation time) the longer the movie-strip - the more information being put together - and the bigger the events (particles) can be seen.

Inertiaand mass is the equivalent of period of movie-strip, is about how many pixels involved in the repetion of a wave-pattern that defines said particle and gravity perhaps best can be seen as the phenomenon of the change itself - and therefore cannot be assigned any kind of existence - because no time can be assigned to the very concept of "change".

Ewol
Not getting on very well so I'll try another one.

Just when we think the formation of the solar system was explained even though we dont know where the mattwer came from I have heard it said that the shockwave caused by the ignition of the sun should have blown most of the accretion disc away so the planets should not have formed.

niels
QUOTE (Ewol+Nov 6 2011, 09:32 PM)
Not getting on very well so I'll try another one.

Before getting to another one I would suggest to put focus on some other issues -

I still miss that the questions about Observer and Scale is seen in the light ot the anthropic principle.

And the fundamental question - about whether physical and true infinite can live together in the same basket.

And the fundamental questions about whether there can be a time axis without CP- violation

Ewol
Your post is not easy to follow.
You seem to be talking about fields that scale up and down. I have thought about all being controlled by a gavity field in one direction and energy field at right angles making 3d spacetime, it sort of works when you picture it, it can up to a point explain Black Holes and the orbits of the planets and will scale from Quantum up to the universe, but I have no way of telling how accurate it is or how to include the other forces as its based on gravity and kinetic energy.

Infinity is a common question, my view is that it is a concept not a number and can only exist outside the finite.

Not sure where you are going with time, there must be a reason for time dilation perhaps time scales as well as the rest of the universe.

Does science contain as many inconsistencies as it claims the bible contains. How much is being swept under the carpet because it is inconsistent with accepted theory?
niels
QUOTE (Ewol+Nov 7 2011, 10:36 AM)
Your post is not easy to follow.
You seem to be talking about fields that scale up and down. I have thought about all being controlled by a gavity field in one direction and energy field at right angles making 3d spacetime, it sort of works when you picture it, it can up to a point explain Black Holes and the orbits of the planets and will scale from Quantum up to the universe, but I have no way of telling how accurate it is or how to include the other forces as its based on gravity and kinetic energy.

Infinity is a common question, my view is that it is a concept not a number and can only exist outside the finite.

Not sure where you are going with time, there must be a reason for time dilation perhaps time scales as well as the rest of the universe.

Does science contain as many inconsistencies as it claims the bible contains. Quote: "How much is being swept under the carpet because it is inconsistent with accepted theory?

hi Ewol

You are right - it is probably not easy to follow - not even for myself - because the ideas are not mainstream - and they are not directly explainable via mathematics - which by the majority is beieng seen as a tremendous weakness - and there is no established nor accepted language.

(imagine if you had to introduce concepts like imaginary particles - event horizon - rubber sheet being effected by mass and not vice Versa - instantaneous - continuous etc etc etc)

My opinion is that when mathematics is being applied to any idea / theory, then at the same time the said insight is being limited to mathematic metaphors and the axiomatic rules of mathematics, which is not necessarily a good thing when we are dealing with the fundamental insight of Universe.

Universe is NOT mathematics - Universe is about how we humans perceive Universe. Human mind IS the interface between noumenal world and fenomenal world, respectively. Physics is about how we humans understand and explain noumenal world by use of metaphors and in this way human tries to explain and understand this translation - which is being governed not only by our so-called physical senses. Copy-paste Wiki: "Senses are physiological capacities of organisms that provide inputs for perception. The senses and their operation, classification, and theory are overlapping topics studied by a variety of fields, most notably neuroscience, cognitive psychology (or cognitive science), and philosophy of perception."

Quote: "You seem to be talking about fields that scale up and down. I have thought about all being controlled by a gavity field in one direction and energy field at right angles making 3d spacetime"

I am not in favor of ideas being dependent on vaquely defined and different "fields" - because there must be something more fundamental behind such fields. And this is where the concept of my fundamental metaphor in the form of "object of sameness" comes into play. And this metaphor can be out-folded in the idea about how such objects of sameness organize themselves scale-wise in a matter-wave dualism, and where universe best can be seen as scales, and how such scales (a scale will by its very definition be finite - whereas there can be an infinite number of scales) can be turned into existence by an observer belonging to the same scale - and observer being made of the same "stuff" as the scale. Yours controlling fields belongs to similar or better to say identical organized scales - but in the next-following Russian Doll scale.

Imagine that gravity IS a derived function of the very phenomenon of change - and that energy fields are the derived functions of what the change has effected. Not easily graspable - but IMO giving rise to a consistent idea.

Time is a derived function of change - and time logically scales as well as rest of universe scale towards smaller and smaller without ever reaching zero. Any time increment can be thought smaller just like any "particle-like" expression can be thought smaller. Mathematics cannot handle such a system IMO, and mathematics cannot as far as I can understand, express the phenomenon of this dynamic ping pong between existence and change. It is more of a philosophical insight.

Quote: "How much is being swept under the carpet because it is inconsistent with accepted theory?"

A lot - I would say.
Ewol
I agree about maths, while it is an excellent way to describe the universe it is the interpretation of those maths that is important and also knowing the limitations the universe applies the the numbers, hence this thread. All I know is that if the universe came out of nothing then when all the numbers are put together the answer must be 0.
Singularities cannot exist because of the limits imposed by the speed of light so any theory that goes to a singularity must go beyond any universal limits.
Logically mass cannot exist so I think theory of everything will be field theory from which mass will emerge, of course that does not explain where the fields come from in the first place. We just have to trust Quantum theory.
Mainstream seems to have problems with tunnel vision, specialists seem to be unable to look outside their own fields, how many of the greats could be described as mainstream.
Take the BB we hear about matter and antimatter anhilation but this must have origionated from energy, anti-energy, perhaps one was attractive and one repulsive the attractive one formed matter leaving gravity as a residual force which is why it is so weak.

Ewol

Regarding redshift I have found out that andromeda is blue shifted, being our closest neighbour in time and distance this suggests that the universe is in fact now collapsing.
AlexG
QUOTE (Ewol+Nov 24 2011, 11:08 AM)

Regarding redshift I have found out that andromeda is blue shifted, being our closest neighbour in time and distance this suggests that the universe is in fact now collapsing.

No.

Andromeda is within our local galactic group, and is too close for expansion to effect it. It is gravitationally bound to the Milky Way and is physically moving towards us.
Ewol
Fair enough but that obviously leads to the following questions.
Everything that is moving away was obviously closer together in the past and so would have been close enough to be gravitationally bound so how did the expansion of space break those gravitational bonds.
By thre same reasoning andromeda must have been a lot further away, presumably far enough not to be gravitationally bound, so must always have been heading in our direction, how does that fit in with the BB and expansion of space.

Are there no explainations as to how the 2d rubber sheet example for gravity works in 3d, I would be most interested in a pictorial example if anyone knows where one can be found.
Ewol