Darren New <dne### [at] sanrrcom> wrote:
> >   No. Space expands, the brick doesn't.

> That doesn't really make sense.

  It makes sense when there's a force opposing the expansion.

  Think about it this way: The distance between atoms in a molecule is
determined by the bounding forces between atoms. These are proportional
to the charge of the electrons, or whatever. It's a constant. It doesn't
change. If you tried to separate the atoms of a molecule, this force would
resist it.

  I suppose it's not too much different than the cause why you don't
drop to the center of the Earth due to gravity: Because there's a force
stopping you from doing so.

>  "Everything gets longer, except your 
> rulers."  It would seem to be changing fundamental physical constants.

  Not everything gets longer. Only intergalactic space, far away from
the galaxies, gets longer.

> >   AFAIK space doesn't expand inside galaxies.

> OK. More weirdness. Have you heard any postulates on why that would be 
> the case? Space only expands where the gravity is sufficiently low? 

http://en.wikipedia.org/wiki/Hubble%27s_law

"In using Hubble's law to determine distances, only the velocity due
to the expansion of the universe can be used. Since gravitationally
interacting galaxies move relative to each other independent of the
expansion of the universe, these relative velocities, called peculiar
velocities, need to be accounted for in the application of Hubble's
law. The Finger of God effect is one result of this phenomenon
discovered in 1938 by Benjamin Kenneally. In systems that are
gravitationally bound, such as galaxies or our planetary system, the
expansion of space is (more than) annihilated by the attractive force
of gravity."

-- 
                                                          - Warp

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