I LIGO & Special Relativity: Is Spacetime Distortion Real?

[zoltrix]

Hello

Is the distortion of spacetime by gravitational waves directly related to the contraction of objects in motion predicted by special relativity ?
In other words
Besides the existence of the gravitational waves , did the LIGO experiment definitely confirm the contraction of the bodies in motion which had never been observed so far ?

 

[PeterDonis]

Is the distortion of spacetime by gravitational waves directly related to the contraction of objects in motion predicted by special relativity ?

No. SR length contraction involves no "distortion of spacetime" at all.

Besides the existence of the gravitational waves , did the LIGO experiment definitely confirm the contraction of the bodies in motion

No. See above.

 

[Dale]

the contraction of the bodies in motion which had never been observed so far

Lorentz certainly believed that Michelson and Morley had observed it. I tend to agree with him on that point.

 

[Nugatory]

... the contraction of the bodies in motion which had never been observed so far ?

It's worth googling for "purcell magnetism length contraction"

 

[Ibix]

At least some sources (e.g. the experimental basis of SR FAQ linked from this forum) do say that there have been no direct tests of length contraction. They mean that we've never actually carried out the rod and barn paradox experiment, and never imaged something moving fast enough that we'd expect to see length contraction. But there are many experiments that have been carried out that require length contraction for their interpretation - for example the cosmic ray muons, as well as the Michelson-Morley experiment and Purcell's explanation of the field around a current carrying wire already mentioned by others.

LIGO does not have anything to do with length contraction. Length contraction is closely related to the fact that a cylindrical rod, sliced diagonally, has an elliptical cross-section. A 3d slice (what we call "an object, now") through a 4d worldtube has a different shape depending on the angle between the worldtube and your definition of "now" - i.e., the object's velocity relative to you. This is a completely separate phenomenon from the specific type of curvature of spacetime which we call gravitational waves.

 

[A.T.]

At least some sources (e.g. the experimental basis of SR FAQ linked from this forum) do say that there have been no direct tests of length contraction.

Where "direct" is a matter of convention. One could argue that all measurements we make are indirect. Is the point that length contraction was not tested for macroscopic objects?

 

[Ibix]

Is the point that length contraction was not tested for macroscopic objects?

That's my reading of it, yes - we haven't done the rod-and-barn paradox scenario in practice. As you say, the distinction between a "direct" and "indirect" test is arguable, but at least some respectable sources do phrase it that way.