Cecil Moore wrote:


Not to worry. Any relativistic motion on our part will only effect
the clocks in the other reference frames. And we can't even
communicate with any of those people. :-)


But, Jim, that other reference frame may be yesterday
on Earth. A second today may be shorter than a second
was yesterday. I can prove that seconds are getting
shorter. It takes me many more seconds to run 100
yards than it once did.

I'm pretty sure that first second after the Big
Bang wasn't anywhere near the length of a second now.

The point is that you have to compare clocks in different reference
frames to know it. The second remains the same in each frame of
reference. Since everything we perceive is perceived with respect to
our own reference frame, we really need only concern ourselves with
our own reference frame. But you can still worry about the other ones
if you really want to. ;-)

73, Jim AC6XG