From: Hubert Mania (humania@t-online.de)
Date: Fri Aug 16 2002 - 00:53:18 MDT
A few words to everybody who commented on the balloon picture:
This balloon picture is not supposed to be a complete cosmological *model*
of the expanding universe. It is no 1:1 correspondence of reality. Like
every analogy it can only serve as a rough but most convenient picture on
the first page of, let's say, "A Young Person`s Guide To Cosmology". Most of
your
comments on the balloon start with a few solid facts about the universe as a
whole and then quickly turn into beliefs, speculations, and scifi-dreams
that are too fancy for this simple analogy to persist. There is one single
objection that I would accept: when you blow up the balloon, the color dots
on the skin expand too and that just doesn`t fit with the observations.
Galaxies themselves - the matter which the galaxies are composed of -
certainly do not expand.
But on the other hand...look at the dough:
Has anyone of you ever made a raisin dough by yourself? The formerly dry
raisins DO expand with the moisture of the dough. So, actually this 3d
expansion of the matter-component within this picture is not fundamentally
different from the expanding color dots which are supposed to be the
2d-equivalent of matter on the ballon skin which itself serves as a "deputy"
of space time.
I guess raisin dough and balloon should both be taken for what they are:
rough sketches that were never intended to hold THE truth and which must
pitifully fail when examined painstakingly. But in order to show that it is
the expansion of space time and NOT of matter, I personally feel the balloon
picture altogether more appealing than the raisin dough.
humania
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