Title: Why is time relative? | Physics Forums
Headings: Why is time relative?
Why is time relative?
onestarburns
Answers and Replies
Jimmy Snyder
Farsight
axawire
Rach3
Gelsamel Epsilon
MeJennifer
BoTemp
Rach3
MeJennifer
MeJennifer
Rach3
MeJennifer
Rach3
MeJennifer
RandallB
MeJennifer
MeJennifer
MeJennifer

Content: I believe there was an astronomer which determined observationally that the speed of light as measured on Earth is independent of the speed of the emitter, but I haven't been able to find anything more specific. Jul 20, 2006
#9
Rach3
I meant simultaneity in the usual sense - for two events (t1, x1), (t2, x2), there is no consistent statement of the form "t1 = t2" except in the trivial case in which it holds in only one Lorentz frame (or else x1=x2, also trivial). The point of "does simultaneity 'exist'" seems entirely semantic to me. It is not uniquely defined, and has no usefullness, so in my narrow, pragmatist worldview I'm not concerned. Jul 20, 2006
#10
MeJennifer
1,997
5
Rach3 said: I meant simultaneity in the usual sense - for two events (t1, x1), (t2, x2), there is no consistent statement of the form "t1 = t2" except in the trivial case in which it holds in only one Lorentz frame (or else x1=x2, also trivial). The point of "does simultaneity 'exist'" seems entirely semantic to me. It is not uniquely defined, and has no usefulness, so in my narrow, pragmatist worldview I'm not concerned. It is obvious that simultaneity exists in the universe because otherwise the universe could not have a causal structure. Last edited: