[time-nuts] UTC and leap seconds

[Mike S]

At 10:46 AM 6/11/2010, iovane at inwind.it wrote...
>(Speculative hint: We accept that the universe is expanding. Might 
>this affect
>the fine structure of matter, including cesium atoms? Is there any 
>adverse
>proof? What is easier to think? a) the expansion of the universe 
>doesn't affect
>at all the properties of matter. b) it might.).

If the expansion affected everything, how would we know? Are you 
claiming that it affects different things differently? Why? (if it 
affects all things equally, then both the earth and clocks would 
slow/speed the same, and we wouldn't observe the earth slowing down)

The universe, as a whole, is expanding. The matter and objects within 
it are not (generally - some things like my beer belly are, but that's 
unrelated to universal expansion). The result is objects, on an 
universal scale, stay the same size but get farther apart. To your 
point (expansion affecting small structure), why would expansion take 
effect at very large scales, and very small scales, but not at the 
scales in between?

But, relativity (not just Einstein's form) can apply everywhere. One 
can create complex math/physics which allows the Earth to be at the 
center of the universe, with everything else revolving (in very complex 
orbits) around it. Having done so, no one can "prove" that it's not 
true. But, that's not what most people accept as "fact," because it is 
FAR from the simplest explanation of what we observe. So, if you want 
to believe that clocks speed up, and the earth's rotation remains 
constant, you can. But don't expect others to accept that.