Expanding Universe & Red Shift

Rulers are not expanding.

The acceleration of expansion (discovered about ten years ago) is due to something given the name "dark energy". No one knows what it really is, although it seems to be related to the "Cosmological Constant" in general relativity.

 

The Perlmutter study injected dark energy into the mix. See
http://physicsworld.com/cws/article/print/31910

 

Bound systems - held together by gravity or electromagnetic forces - can oppose the expansion so they don't change. At least for now.

Newton still holds, but we presently don't know what is causing the observed acceleration. There are lots of theories, but no definite answers as yet. That's why we're still making bigger and better telescopes to study it further. If we knew why, then the need for the scopes would be less.

Beware of physicists with too many answers. They might be trying to sell you something ;-)

 

universe is expanding. maybe not! think if the photons ,we see in Hables telescope, are with more or less energy they change colors spectre - so if in middle of universe is huge super-massive black hole , which evidence universe , then on its way photon loose energy and we see it as red or violet or blue..

 

Dex, check out Professor Ned Wright's discussion of why "Tired Light" models don't work to explain the red-shift.

 

uh thanks!!! thats help a lot....
anyway - do we have thread - how universe is made?

btw it was idea i made myself - that i liked ;(

 

Start that thread yourself over in the https://www.physicsforums.com/forumdisplay.php?f=69".