sananda Posted August 31, 2009 Posted August 31, 2009 If one has a very long stick, say 1 light year long that is not compressible and one moves it through space. Ignoring inertial problems isn't one sending data from one side of the stick to an observer at the other at a speed faster than light. Discuss.
Bob_for_short Posted August 31, 2009 Posted August 31, 2009 If one has a very long stick, say 1 light year long that is not compressible and one moves it through space. ... isn't one sending data from one side of the stick to an observer at the other at a speed faster than light? Discuss. Yes, one does. The problem is in impossibility to physically create such a non-compressible stick. Physycally you create a sound wave or a shock wave in the stick to start moving the other side. 1
Sisyphus Posted August 31, 2009 Posted August 31, 2009 What that thought experiment demonstrates is that there is an upper limit on the rigidity of an object. The motion can't travel down the stick as fast or faster than the speed of light. Moving one end would create a wave moving at sublight speeds down its length.
insane_alien Posted August 31, 2009 Posted August 31, 2009 as bob says. the problem is you are trying to apply physics to something that is inherintly physically impossible. so any answer is neither right or wrong. just completely irrelevant. assuming that the rod is a stiff as physically possible(which is still far stiffer than any known material even some hypothetical ones) the signal will travel at the speed of light.
sananda Posted August 31, 2009 Author Posted August 31, 2009 What about the experiment with 2 electrons separated by space, observation of one affects the other... Is that not faster than light data transmission? could space-time be like the stick, and gravity like the push on the stick?
insane_alien Posted August 31, 2009 Posted August 31, 2009 quantum entanglement does not transmit information.
swansont Posted August 31, 2009 Posted August 31, 2009 Or, to be more specific, quantum entanglement cannot be used to transmit information FTL. The summary the "observation of one affects the other" is easily and often misinterpreted.
sananda Posted August 31, 2009 Author Posted August 31, 2009 yes but could gravity be used to transmit information? has it been proven to be = light speed or is it just a theory?
ajb Posted August 31, 2009 Posted August 31, 2009 has it been proven to be = light speed or is it just a theory? You can show that in the context of general relativity that gravity travels at the speed of light in the sense that the ripples in space-time caused by varying an object travel at the speed of light. That is the effect of "something happening " can be transmitted via gravity at the speed of light. (Just as electromagnetic effects travel at the speed of light. ) This is in agreement with astronomical data. I am sure if you google you will find some experimental bounds.
sananda Posted August 31, 2009 Author Posted August 31, 2009 has it been proven though, this link says it is at least 20 times as fast as light http://www.metaresearch.org/cosmology/speed_of_gravity.asp This would support a hypothesis suggesting that gravity is a flow of ZPF energy, where as light is a wave through that same medium. Correct?
Sisyphus Posted August 31, 2009 Posted August 31, 2009 That link actually says 2*10^10 C, or 20,000,000,000 times the speed of light. However, that is not a scientific paper, just some dude's thoughts. General relativity predicts that gravity propagates exactly at C, and experiments, though still insufficiently precise, support that.
sananda Posted August 31, 2009 Author Posted August 31, 2009 looking at wikipedia it seems disputed that the expirements have any merit and that they simply calculate c in a roundabout way.
ajb Posted September 2, 2009 Posted September 2, 2009 (edited) has it been proven though, this link says it is at least 20 times as fast as light It has been proven in the sense that you can write down solutions to the linearised field equations of general relativity and show that the wave solutions travel at the speed of light. These are the gravitational waves. These waves are how, at least classically small fluctuations in gravity are transmitted. This seems to agree with just about all experimental/observational evidence that I am aware of. Including careful study of binary pulsars, which so far provide the best evidence of gravitational waves. So, I would accept that the speed of gravity is calculated in a round about way. One assumes that physical gravitational waves travel at the speed of light then show that the predicted effects of gravitational radiation agree with theory, and thus we confirm that gravitational waves travel at the speed of light. A direct observation of gravitational waves would be great and people are working on this. Maybe at some point a Michelson–Morley type experiment could be carried out. Edited September 2, 2009 by ajb
D H Posted September 2, 2009 Posted September 2, 2009 has it been proven though, this link says it is at least 20 times as fast as light http://www.metaresearch.org/cosmology/speed_of_gravity.asp What Van Flandern did in that link was to create a straw man of general relativity and then prove that that straw man version of general relativity is false. Van Flandern's reasoning would be correct if the only difference between general relativity and Newtonian mechanics was that general relativity adds a finite transmission speed for gravity to Newtonian mechanics. That of course is not all there is to general relativity. There are effects in general relativity such as frame dragging that nearly cancel the effects of a finite transmission speed of gravity, particularly for objects well removed from and moving slowly with respect to a gravitational source. General relativity reduces to Newton's law of gravity under these conditions (far from and moving slowly with respect to a massive body). What about cases where those conditions don't quite apply? Mercury is close to the Sun and is moving fairly fast with respect to the Sun. One well known problem in physics at the end of the 19th century was that measurements of the precession of Mercury did not agree with predictions based on Newtonian mechanics. General relativity fully explained the discrepancy, and did so with no tweaking to make it match observation. The gravitational aberration upon which Van Flandern bases much of his argument is also incorrect. See http://arxiv.org/abs/gr-qc/9909087 for details. Van Flandern never understood general relativity, but he certainly did know how to misinterpret it.
Gasparri Posted September 2, 2009 Posted September 2, 2009 yes but could gravity be used to transmit information? has it been proven to be = light speed or is it just a theory? The whole notion of transluminal speeds is interesting. I have found at least one case (that implies there are more) where light seems to travel faster than light. This I see as virtual but the fact is the question remains unanswered as far as I know. Here it is, you can plainly see this laid out in black & white here: Two things are big hangups as they are non entities. These are Gravity and Time. Neither exist in reality but in the virtual world of the human mind they do, as mirages that cannot be approached. Gravity is a result, nothing more. It has no entity, no particle, no wave. No graviton will ever be found by CERN. Time is simply a method of metrication of motion and nothing more. Motion and time are one in the same thing equally resolvable as as something they are not. There will be no time travel. A trillion years ago and 1 day from now are the same instance timewise but motionwise things are always changing. Obama wants change? Look at the universe, that's all it is. Change. I await my asschewing by those that 'know' the truth.
Sisyphus Posted September 2, 2009 Posted September 2, 2009 If you wouldn't pull things out of it and put them on the internet, it probably wouldn't get chewed as much.
ydoaPs Posted September 2, 2009 Posted September 2, 2009 The whole notion of transluminal speeds is interesting. I have found at least one case (that implies there are more) where light seems to travel faster than light. This I see as virtual but the fact is the question remains unanswered as far as I know. Here it is, you can plainly see this laid out in black & white here: Two things are big hangups as they are non entities. These are Gravity and Time. Neither exist in reality but in the virtual world of the human mind they do, as mirages that cannot be approached. Gravity is a result, nothing more. It has no entity, no particle, no wave. No graviton will ever be found by CERN. Time is simply a method of metrication of motion and nothing more. Motion and time are one in the same thing equally resolvable as as something they are not. There will be no time travel. A trillion years ago and 1 day from now are the same instance timewise but motionwise things are always changing. Obama wants change? Look at the universe, that's all it is. Change. I await my asschewing by those that 'know' the truth. I've traveled here from 1988 to ask you what you're smoking and if I can have some.
swansont Posted September 3, 2009 Posted September 3, 2009 (edited) I've traveled here from 1988 to ask you what you're smoking and if I can have some. Be nice, and remember you are subject to random urinalysis. ———————— I really dislike videos as a substitute for writing, even when they aren't from some speaking slowly and sketching badly. You can't quote them to address specific topics, and much like simply copy-paste word wallpapering from some other site, it's far too easy to simply create a BS overload. If you want a critique, take the time to type in a summary of the hypothesis. Merged post follows: Consecutive posts merged Mod note: mobius strip discussion moved here Edited September 3, 2009 by swansont Consecutive posts merged.
<Ragnarok> Posted September 3, 2009 Posted September 3, 2009 Gravity is a constant. Light is but isn't. If you say put a slit of wood infront of that light it stops being lit. try to put a slit of wood in gravity...nothing. =D
D H Posted September 3, 2009 Posted September 3, 2009 umm what? Full moon is tomorrow, September 4, at 16:05 UTC. We are being attack by a wave of lunatics.
Sisyphus Posted September 3, 2009 Posted September 3, 2009 I think he's just saying you can block light but not gravity. True, but not clear what his point is.
Gasparri Posted September 3, 2009 Posted September 3, 2009 Full moon is tomorrow, September 4, at 16:05 UTC. We are being attack by a wave of lunatics. You live under the same moon as they do. When is someone going to address the acceleration of light? Is there such a thing and if so can it be expressed as zero to 300,000 Km in one second flat? :-D
insane_alien Posted September 3, 2009 Posted September 3, 2009 light doesn't accelerate. it can't go at an speed other than c
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