Doug Pensinger wrote:
>
>> >1) Why do some galaxies collide if everything is supposed to be expanding? I
>> >assume that the reason is some post BB phenomenon, but have no idea what that
>> >might be.
>> >
>> No, the reason is simpler than that. The expansion of the big U is a *global*
>> phenomenon, that doesn't prevent local collisions.
>
>I don't get it, could you expand on that?
>
Ok.
Global means that we are taking the big U as a whole mess of stuff
Local means that we just looking at small part of it.
For example, let's talk about Global Warming. The Earth, as a whole,
is getting warmer. But some parts of it may be cooling. This cooling is
a local phenomenon.
>
>>The *problem* with BB Theory is explaining *why* there are galaxies, and not
>>just a uniform soap of atoms :-)
>>
>
>But this seems far more intuitive to me. Wouldn't matter have a tendency to
>congeal with the forces that caused the attraction in the first place
>increasing as the mass increased?
>
No! It's a Buridan's ass's case: why would matter go into any direction, if all
directions pull with the same force?
Alberto Monteiro
