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I always struggle with the time concept when it comes to general relativity. In the recent discovery the gravitational waves have been detected by the "displacement" of the mirrors and the difference that occurred between the "lengths" of the two arms. Which seems to me that it only dealt with the spatial parameters to see the ripples.

My question is that, we have seen that chirp from the spatial point of view, but what was the effect of the passage of such a "space-time" wave on our clocks? I mean, if we saw the distortion of the space, what change could we see in time?

user2326844
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  • If it has been answered direct me to the link please. – user2326844 Feb 12 '16 at 06:37
  • see the link above or my answer here which also addresses this: http://physics.stackexchange.com/questions/233394/space-time-and-gravitational-fields/233521#233521 – JPattarini Feb 12 '16 at 07:09
  • yes, I know the link to the question - but all I saw there were comments and a couple of answers which did not really address the question. To me, lasers are electromagnetic waves which are not "space-time" waves. How could we use them as a gauge to detect a more general concept like "space-time" gravitational waves? How can we rationalize this separation we have done in measuring spatial properties from time when they seem to be so entangled in this matter? – user2326844 Feb 12 '16 at 07:40
  • Please read my full answer that I linked you to above, it directly addresses this. We have no difficulty comparing the "tick" rate of highly accurate clocks placed at different altitudes, nor traveling at different speeds. In fact we have to take this into account in order to use GPS. Likewise, we can use a ranging laser to measure the width of a room (done every day). A gravitational wave can be detected in deltas to both: the width of my room may suddenly read slightly larger/smaller, and my clock may suddenly lose synchronicity with a synched partner. – JPattarini Feb 12 '16 at 08:47
  • yes, your last paragraph has explained your point of view. As far as I understood you are saying that we can narrow down the concept of "space-time" to the scales we have at hand to detect the existence of the gravitational waves. But, I am still not convinced. I believe that user3688410 link is right. LIGO experiment could have been done by satellites with synchronized clocks and at the same time laser detectors. At least in this way, we could detect and at the same time "measure" what was detected. – user2326844 Feb 12 '16 at 10:58

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