66. More on time

Further to my post 65 on time, here is a google search result on the same question.



From: Chris Ho-Stuart <>
Newsgroups: aus.religion.christian,aus.religion,nz.soc.religion
Date: Friday, 12 March 1999 9:54
Subject: Re: Some hard questions for Able


In aus.religion.christian Able <> wrote:
> >More seriously, I honestly have no idea what "eternity past"
> >means if it does not refer to duration in time; so I am not
> >persuaded that the question was ever meaningful.
>
> Let me put it more simply..
> When did time begin?

About 15 billion years ago.

Note that I really do mean that time itself does not extend
indefinitely into the past. It is not simply the case that
15 billions years ago the universe began, and before that
there was no universe. I mean that the question of time
before 15 billion years is a bit like dividing by zero. It
is not defined. The assumption that time is a continuous flow
against which we measure events turns out to be false. Time
and space and matter are all part of the same structure, and
that structure does not extend indefinitely into the past.

That is, assuming that "eternity past" has something to do
with duration of time into the past, it turns out that there
is no such thing as eternity past.

This answer was not obtained simply by logic. Logic is
nothing more than a disciplined way of reexpressing your
initial assumptions.

It was not obtained by faith.

It was obtained by the usual scientific tools of observe, theorize,
experiment, test, repeat indefinitely. The conclusion is, like
anything else we know, never absolute. We simply do not have direct
access to perfect knowledge. As far as conclusions go in science,
the conclusion of a strict bound to time itself in the past is
pretty solid. By way of contrast, there is not definite conclusion
on whether or not space is open or closed: that it -- unbounded
and infinite or bounded and finite.

These ideas are not easy to explain. Generally, if the universe
is closed then it has a finite extent, and a finite number of
particles, and a finite future: time itself is bounded in past and
future. If the universe is open then it has infinite extent, and an
unbounded number of particles, and time will persist indefinitely.
One of the puzzles of modern cosmology is that the universe appears
to be nears as dammit to "flat"; hence the question of being open
or closed is still an open question.

However, in all these cases time is bounded in the past.

For a brief introduction, I strongly recommend the following
web sites:
Best: Ned Wright' cosmology tutorial; by a professional
cosmologiest at UCLA. Widely recommended by other
scientists.
http://www.astro.ucla.edu/~wright/cosmolog.htm

An introduction to cosmology at Nasa.
http://map.gsfc.nasa.gov/html/web_site.html

Nasa also supports "Ask the Space Scientist"
Many of the topics you touch upon are addressed.
http://image.gsfc.nasa.gov/poetry//ask/askmag.html

For the real nitty gritty, however, nothing beats a solid foundation
provided by careful study in a print library: including the hard work
of getting around a lot of fundamental mathematics and physics; with
the aim of being able to read and comprehend the published scientific
literature. This is not a matter of being exclusive. Anyone with a
reasonable interest, and some aptitude for maths, would be able with
some hard work to get a grasp of modern cosmology. It helps also to
bear in mind that one needs to question some assumptions that are so
deeply grained we are often not even aware of them as assumptions;
and that one will make plenty of errors along the way.

Cheers -- Chris



top