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A comment on Seven earth-sized planets discovered circling a star 39 light years from Earth. Parent comment

Re:Seven earth-sized planets discovered circling a star 39 l... by Symmetry on Wednesday February 22, 2017 @04:06PM (#13709154)
Special relativity says that no matter what your velocity is relative to Earth you can proclaim that you're actually at rest and it's the other guy that's moving. So your velocity is always continuously being "reset". And in each of the frames of reference of everything in existence nothing else is traveling faster than the speed of light.
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Re:Seven earth-sized planets discovered circling a star 39 l... by 4_more_ken on Thursday February 23, 2017 @04:26PM (#13717944)
The 1905 Special Relativity Theory (1905 SRT) version of reciprocity implies that the other guy in a different inertial frame than your own will be the one that is moving. The consequence of this implication is the "Twin Paradox" (i.e. both twins in different inertial frames have been accelerated and are both aging slower than the other twin). A different version of reciprocity that implies that the accelerated twin is moving and the apparent movement of the twin that has remained stationary is only an aberration (or mirage) is axiomatic because movement first requires acceleration.
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Re:Seven earth-sized planets discovered circling a star 39 l... by wallace_f on Wednesday February 22, 2017 @10:27PM (#13711389)
Assuming spacetime is not expanding, let's say 1 galaxy is moving away from us at .9c. I leave our galaxy and catch it by travelling at .99c. Then a citizen of that galaxy, at rest, accelerates to .9c. So his velocity relative to earth is .89c? I think I need to go watch a youtube video on special relativity. Intertial reference frames are really weird.
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