Theory of relativity in the world of bats.

[Bart]

Has anyone wondered how it looked to the theory of relativity, in the world of bats?

 

Assume that in this world there is no light, and the bats know nothing about it.

 

The only medium to measure the speed and distance, are the waves of sound of their maximum speed of 340 m / s.

 

Do according to their theory of relativity, the speed limit for the particles, therefore, was to 340 m / s?

 

Do as it approaches of their vehicle to the speed of sound, would have also changed their time and mass in the same way as in SR?

 

Please do not use in considerations the speed of light, because for the bats it does not exist.

Edited October 13, 2011 by Bart

[insane_alien]

no, maximum particle velocity would not be 340 m/s

 

you could still build a gun that has a muzzle velocity of 900m/s and fire it.

 

from the bats perception the bullet arrived before the gun was fired but this is not actually the case.

 

and you can't exclude light even if it can't be percieved. it is still there, photons are still exchanged and are required for there to be matter.

[John Cuthber]

There would not, in principle, be anything to stop a bat flying supersonically. It would be impractical and take a lot of energy, but it's perfectly feasible.

[Janus]

Has anyone wondered how it looked to the theory of relativity, in the world of bats?

 

Assume that in this world there is no light, and the bats know nothing about it.

 

The only medium to measure the speed and distance, are the waves of sound of their maximum speed of 340 m / s.

 

Do according to their theory of relativity, the speed limit for the particles, therefore, was to 340 m / s?

 

Do as it approaches of their vehicle to the speed of sound, would have also changed their time and mass in the same way as in SR?

 

Please do not use in considerations the speed of light, because for the bats it does not exist.

 

No. The speed of sound is not invariant, it is measured relative to the medium ( in this case, the air), light requires no medium to propagate. If a bat were to perform the sound equivalent of the M and M experiment while flying, it would be able to get a result that gave its velocity with respect to the the air. What makes anything traveling at c special is that everyone gets the same answer for its value when measured with respect to themselves. This does not happen with sound. You can change the speed at which sound moves relative to yourself by moving with respect to the air that the air is moving through.

[swansont]

As an example of what Janus said, in the lesser known movie "Bats on a Train" a bat in an enclosed train car makes a sound and it travels at the speed of sound + the speed of the train, according to an observer on the ground. Not the kind of result you would get for light.

[Moontanman]

As an example of what Janus said, in the lesser known movie "Bats on a Train" a bat in an enclosed train car makes a sound and it travels at the speed of sound + the speed of the train, according to an observer on the ground. Not the kind of result you would get for light.

 

 

Swansont you are a spoil sport, but always accurate, but let us take the analogy further, lets say the bats and sound in their reality is equivalent to ours and light in our reality but both of us are unaware of transmissions faster than sound or light, could such motion be explained, inside of relativity if they were discovered? Sound and light are not equivalent, I do understand that but I am always full of "what if" questions (not to mention other stuff ) and I wonder just how resilient the idea of nothing can travel faster than light really is, what if we did find a way to transmit information faster than light, would it redefine causality or relativity or neither?

Edited October 13, 2011 by Moontanman

[DrRocket]

Has anyone wondered how it looked to the theory of relativity, in the world of bats?

 

Assume that in this world there is no light, and the bats know nothing about it.

 

The only medium to measure the speed and distance, are the waves of sound of their maximum speed of 340 m / s.

 

Do according to their theory of relativity, the speed limit for the particles, therefore, was to 340 m / s?

 

Do as it approaches of their vehicle to the speed of sound, would have also changed their time and mass in the same way as in SR?

 

Please do not use in considerations the speed of light, because for the bats it does not exist.

 

The speed of a compression wave in air is NOT the "speed of sound. The speed of such a wave is weakly dependent on the amplitude of the wave, as well as the temperature. The "speed of sound" is the limit of the speed of propagation under given conditions as the amplitude vanishes. Moreover the "speed of sound" is relative to the preferred reference frame in which the air is stationary. A flying bat would not represent that frame.

 

Thus the speed of a compression wave in air does not mimic the axiom of special relativity under which the speed of light in a vacuum is independent of the inertial reference frame , and there would not be any analogous "theory of relativity" for bats.

[Schrödinger's hat]

All of the strange effects of relativity come from the concept that there is a speed that is the same in all frames.

It is not really important that it is the speed of light. It could be the speed of sandwich and it would have the same effect.

Although, even if it were the speed of sandwich, you would still be unable to pass such a speed with finite momentum.

 

would it redefine causality or relativity or neither?

 

It would do at least one of these things.

Causality could stay intact if there was a detectable absolute reference frame (thus breaking lorentz symmetry). If this was the case, things would only be able to exceed the speed of light in some directions/frames of reference. In this absolute frame, the past would always effect the future.

In other reference frames, there would be a seemingly arbitrary hard limit on the speed you could send a signal.

If Lorentz symmetry were retained, then superluminal travel is equivalent to time travel, at least in principle.

[baric]

OK, we are assuming that bats evolve enough intelligence to grasp the concept of relativity.

 

And, just like us, they will eventually build devices to send and detect photons at wavelengths invisible to their sight (radio, gamma, etc). And remember that, for most of history, humans could not "see" light traveling. It was always considered to be instantaneous. We had to use equipment to realize that light traveled at a certain speed.

 

Once chiropteran scientists can also build this equipment, they will quickly surmise that all radiation travels at c.

 

Their theory of relativity will be no different.

Edited October 14, 2011 by baric

[imatfaal]

OK, we are assuming that bats evolve enough intelligence to grasp the concept of relativity.

 

And, just like us, they will eventually build devices to send and detect photons at wavelengths invisible to their sight (radio, gamma, etc). And remember that, for most of history, humans could not "see" light traveling. It was always considered to be instantaneous. We had to use equipment to realize that light traveled at a certain speed.

 

Once chiropteran scientists can also build this equipment, they will quickly surmise that all radiation travels at c.

 

Their theory of relativity will be no different.

 

Just as a note (and because I find it pretty amazing) Empedocles in the 4th century BC claimed that the speed of light was finite (although I believe we have lost his actual argument) - additionally the Arab thinkers Avicena and Alhazen in late 12th and the English monk Roger Bacon in the 13th all had logical theories that they felt proved the finite speed of light.

[J.C.MacSwell]

Has anyone wondered how it looked to the theory of relativity, in the world of bats?

 

Assume that in this world there is no light, and the bats know nothing about it.

 

The only medium to measure the speed and distance, are the waves of sound of their maximum speed of 340 m / s.

 

Do according to their theory of relativity, the speed limit for the particles, therefore, was to 340 m / s?

 

Do as it approaches of their vehicle to the speed of sound, would have also changed their time and mass in the same way as in SR?

 

Please do not use in considerations the speed of light, because for the bats it does not exist.

 

With sound you have a preferred reference frame, that of the rest frame of the air.

[Bart]

OK, we are assuming that bats evolve enough intelligence to grasp the concept of relativity.

 

And, just like us, they will eventually build devices to send and detect photons at wavelengths invisible to their sight (radio, gamma, etc). And remember that, for most of history, humans could not "see" light traveling. It was always considered to be instantaneous. We had to use equipment to realize that light traveled at a certain speed.

 

Once chiropteran scientists can also build this equipment, they will quickly surmise that all radiation travels at c.

 

Their theory of relativity will be no different.

 

 

I wonder if we are not such symbolic Batmans who use light waves instead of sound waves?

 

 

What will be with SR theory if, at some future, it appears that there is unknown to us (like a light for bats), ultra-fast medium UFM, in which information signals may be transmitted to a million or more times faster than light, and this medium is already commonly used by more advanced civilizations in the cosmos.?

[Schrödinger's hat]

I wonder if we are not such symbolic Batmans who use light waves instead of sound waves?

 

 

What will be with SR theory if, at some future, it appears that there is unknown to us (like a light for bats), ultra-fast medium UFM, in which information signals may be transmitted to a million or more times faster than light, and this medium is already commonly used by more advanced civilizations in the cosmos.?

 

If that happens one of two assumptions must be abandoned:

Causality -- Effects happen after causes.

The principle of relativity -- There is no preferred reference frame.

 

The problems with the former are probably self-apparent, but there are also issues with the latter. Instead of a nice unified theory, we'd have a hodgepodge of different mathematical relationships that just happen to be lorentz invariant.

[farmboy]

With regards to what I think the OP was asking, an inability to sense light (i'm not sure that this is actually true in all bats) would probably have retarded our discovery of relativity. WOuld it have prevented it completely or led us to come to some crazy conclusion about the speed of sound? No.

[Schrödinger's hat]

With regards to what I think the OP was asking, an inability to sense light (i'm not sure that this is actually true in all bats) would probably have retarded our discovery of relativity. WOuld it have prevented it completely or led us to come to some crazy conclusion about the speed of sound? No.

 

Hmm. I'm not even sure if this is the case.

The precursor to our discovery of relativity was knowledge of Maxwell's equations. This in turn came from knowing about magnetism, which we can't sense directly.

Certainly the idea that light had a speed (which was proposed since classical times) would have helped, but discovering the concept of a speed as a law of physics is what lead to relativity.

I think it could even be argued that not being used to light and thus used to the idea of knowing about remote things immediately (or indistinguishably close to immediately) could be helpful for understanding relativity.

If we'd never developed a concept of the present, but instead only thought of 'things we are effected by', 'things we can effect', and 'other' then I think relativity would seem quite natural, and maybe even self-apparent upon discovering the equations governing radio waves.

 

But this is all wild speculation, there's no way of knowing this unless we genetically engineer completely blind but super-intelligent bats and watch them for a few Millennia without interfering in their development.

[Bart]

If that happens one of two assumptions must be abandoned:

Causality -- Effects happen after causes.

The principle of relativity -- There is no preferred reference frame.

 

The problems with the former are probably self-apparent, but there are also issues with the latter. Instead of a nice unified theory, we'd have a hodgepodge of different mathematical relationships that just happen to be lorentz invariant.

 

Is very quick receiving information about a distant event, not an effect after the cause?

 

 

If I understand correctly, with this causality is perhaps now not everything so clear. Light signals reaching us from distant galaxies, show us their state before the billions of years from now. At the moment many of these very distant galaxies may well no longer exist.