Mass and angular momentum, left ambiguous by Einstein, get defined
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Mass and angular momentum, left ambiguous by Einstein, get defined
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Re: Mass and angular momentum, left ambiguous by Einstein, get defined
#2The most eye-opening thing I've learned about relativity in the past few years is that the notion that space has no preferential direction is an axiom in the theory.
There's nothing about the way we measure the speed of light that would disambiguate if light traveled instantaneously in one direction and at half the measured speed of light in the other. We just don't have a way to know, because time measurements require information to re-converge at the original site of the experiment's beginning.
It's a pretty good axiom, because we also have no reason to believe there's a preferred direction in space... But it's an axiom.
Re: Mass and angular momentum, left ambiguous by Einstein, get defined
#3The most eye-opening thing I've learned about relativity in the past few years is that the notion that space has no preferential direction is an axiom in the theory. There's nothing about the way we measure the speed of light that would disambiguate if light traveled instantaneously in one direction and at half the measured speed of light in the other. We just don't have a way to know, because time measurements requi…
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Re: Mass and angular momentum, left ambiguous by Einstein, get defined
#4The most eye-opening thing I've learned about relativity in the past few years is that the notion that space has no preferential direction is an axiom in the theory. There's nothing about the way we measure the speed of light that would disambiguate if light traveled instantaneously in one direction and at half the measured speed of light in the other. We just don't have a way to know, because time measurements requi…
Veritasium has a nice video about it on YouTube. We can only measure the average back and forth speed of light.
Re: Mass and angular momentum, left ambiguous by Einstein, get defined
#5No post body was provided.
Re: Mass and angular momentum, left ambiguous by Einstein, get defined
#6I really appreciate articles that don't just say what a new thing reveals, but puts it in a context of what we still don't know.
Re: Mass and angular momentum, left ambiguous by Einstein, get defined
#7Maybe a year ago, possibly here, I finally saw gyroscopic precession demonstrated in a way that didn’t invoke magic thinking. The person simply pointed out that the mistake is in thinking of the rotating mass as a stationary object, when in fact you are applying the lateral force to a different spot on the object at each time interval, leading to very strange vectors.
Re: Mass and angular momentum, left ambiguous by Einstein, get defined
#8The most eye-opening thing I've learned about relativity in the past few years is that the notion that space has no preferential direction is an axiom in the theory. There's nothing about the way we measure the speed of light that would disambiguate if light traveled instantaneously in one direction and at half the measured speed of light in the other. We just don't have a way to know, because time measurements requi…
> But it's an axiom.
I don't agree. If light traveled instantaneously in one direction, then if we looked in the opposite direction (where such light originates from) we would be seeing stars and galaxies at much more recent time (now). Also, their light would have traveled a much longer distance (due to the ongoing expansion of space) and so would be redshifted much more. All in all what we see on the sky would look very differently in terms of redshifts, matter distribution and so on – unless of course there's no isotropy, i.e. unless there's some cosmos-sized conspiration that fine-tuned matter distribution, distances etc. in such a way that the universe looked isotropic to us even though it is not.
Re: Mass and angular momentum, left ambiguous by Einstein, get defined
#9The most eye-opening thing I've learned about relativity in the past few years is that the notion that space has no preferential direction is an axiom in the theory. There's nothing about the way we measure the speed of light that would disambiguate if light traveled instantaneously in one direction and at half the measured speed of light in the other. We just don't have a way to know, because time measurements requi…
That’s not an axiom, it’s an assumption. Anyway, it’s the assumption of isotropy.
Re: Mass and angular momentum, left ambiguous by Einstein, get defined
#10The most eye-opening thing I've learned about relativity in the past few years is that the notion that space has no preferential direction is an axiom in the theory. There's nothing about the way we measure the speed of light that would disambiguate if light traveled instantaneously in one direction and at half the measured speed of light in the other. We just don't have a way to know, because time measurements requi…
> But it's an axiom. I don't agree. If light traveled instantaneously in one direction, then if we looked in the opposite direction (where such light originates from) we would be seeing stars and galaxies at much more recent time (now). Also, their light would have traveled a much longer distance (due to the ongoing expansion of space) and so would be redshifted much more. All in all what we see on the sky would look…
I get what you are saying, it suggests there is no preferred direction, but it is just an inference. The point is one cannot create an experiment to measure the speed of light other than a round trip average speed.