From: Todd W. Thompson
To: All Msg #71, Mar-31-93 01:41PM
Subject: Big Bang/Big Crunch theory discredited?
From: todd@csrnxt1.ae.utexas.edu (Todd W. Thompson)
Message-ID:
Newsgroups: talk.origins
Prelude: I'm taking a class entitled Atheism and its Critics at Rice
University. It requires a paper at the end. My subject is creationism.
Note that I'm not asking for my paper to be written for me, but references
for replies WOULD be nice so that I can do appropriate research.
Ok, on the the important part:
I just read an article entitled Philosophical and Scientific Pointers to
Creatio ex Nihilo by William Lane Craig. It appeared in the Journal of the
American Scientific Affiliation in March of 1980. I have no idea what his
qualifications are, nor those of the scientists he quotes. His basic point
in the article is that the universe MUST have had a beginning. He proves his
point using four proofs, 2 philosophical and dealing with the nature of
actual infinity, and 2 scientific. I'll address the scientific here.
Basic summary of the first:
In 1929 Hubble observed that the universe was expanding in all directions.
The conclusion from that was that at some point in the past, the ENTIRE
KNOWN UNIVERSE WAS CONTRACTED DOWN TO A SINGLE POINT, from which is has been
expanding ever since. [emphasis his] So, if you go far enough back, the
universe finally reaces a point of infinite density (ie. nothingness. If
something were there, it wouldn't be infinite density) He then notes that
this disturbed many scientists, as it was too close to the Christian idea
of the creation of something from nothing for comfort. So, he looks at the
two alternatives, the steady state model and the oscillating model.
He discredits the steady state model (and quotes from physicist Jaki here,
any idea what his reputation is?) through the existence of background radiation
which indicates the universe was once in a very hot and very dense state. In
the steady state model, no such state could have existed. "According to
Ivan King, 'The steady-state theory has now been laid to rest, as a result
of clear-cut observations of how things have changed with time.'"
Question: Is this summary a valid disproof of the steady-state model?
Then he goes on to attack the oscillating model. He says that the key question
is whether or not the univese is open or closed. If it is closed, then the
expansion will reach a certain point, and then the force of gravity will
pull everything together again. (note that he is not speaking of
thermodynamically closed here. That's later) But if the universe is open,
then the expansion will never stop, but will just go on and on forever.
"Scientific evidence seems to indicate that the universe is open. The crucial
factor here is the density of the universe. Scientists have estimated that
if there are more than about three hydrogen atoms per cubic meter on the
average throughout the universe, then the universe would be closed. That
may not sound like very much, but remember that most of the universe is just
empty space. I shall not go into all the technicalities of how scientists
measure the density of the universe, but let me simply report their
conclustions. According to the evidence, the universe would have to be at
least ten times denser than it is for the universe to be closed. Therefore,
the universe is open by a wide margin. Let me share with you the conclusion
of Alan Sandage: (1) The universe is open, (2) the expansion will not reverse,
(3) THE UNIVERSE HAS HAPPENED ONLY ONCE and the expansion will never stop."
"The evidence therefore appears to rule out the oscillating model, since it
requires a closed universe. But just to drive the point home, let me add that
the oscillating model of the universe is only a theoretical possibility, not
a real possibility. As Dr. Tinsley of Yale observes, in oscillating models
' even though the mathematics SAYS that the universe oscillates, there is
no known physics to reverse the collapse and bounce back to a new expansion.
The physics seems to say that those models start from the big bang, expand,
collapse, then end.'"
Ok, there's the first argument. The second one deals with thermodynamics.
First the author goes through a fairly good summary of the basic principles
of entropy and heat death and so on. Actually, rereading this, the second
argument rests on the conclusions of the first, so the evaluation of the
above would be nice. HOWEVER, he says that "as several scientists have pointed
out, each time the model universe expands it would expand a little further
than before. Therefore, ir you traced the expansions back in time they would
get smaller and smaller and smaller. Therefore, in the words of one
scientific team, "The multicycle model has an infinite future, but only a
finite past." As yet another writer points out, this implies that the
oscillating model of the universe still requires an origin of the universe
prior to the smallest cycle."
So, there it is. Are these logical, scientific conclusions or theological
propoganda? With reasons, please, and references, if you can. Or, if you
are unable to tell me the answer, could you direct me to someone who would
know?
Did anyone even get this far? :) Sorry for such a lengthy article, but I
thought it was fascinating. Perhaps this is an appropriate line to employ
against creationists. IF it could be shown that there is a causal force
that spun the universe, the mechanics of evolution or life on earth
would be completely unimportant theologically, since evolution no longer
threatens the concept of the divine hand doing its work, too. Or maybe
that's just wishful thinking. It's something to think about, anyways.
Todd
--
"When the last of a thousand candles burns out, the darkness will always
return; though a thousand voices sing all the hymns of life, silence always
waits upon the inevitable failing of their breath."
-Barbara Hambly, _The Silicon Mage_
====================================================================
From: Tim Thompson
To: All Msg #72, Mar-31-93 05:43PM
Subject: Re: Big Bang/Big Crunch theory discredited?
Organization: Jet Propulsion Laboratory
From: tjt@scn1.Jpl.Nasa.Gov (Tim Thompson)
Message-ID: <1pdhcdINNne4@elroy.jpl.nasa.gov>
Reply-To: tjt@scn1.Jpl.Nasa.Gov
Newsgroups: talk.origins
Basically, the "big bang" model is alive and well. The primary complaint
against a steady state, to the best of my knowledge, is that it is not so
consistent with both known microwave background radiation, and primordial
elemental abundances (and baryon/lepton ratios, I believe). There are
proponents of steady state cosmology; Fred Hoyle just published two lengthy
papers in the las month or so in Astrophysics and Space Science, however, the
large majority accept the big bang, perhaps with "inflation" tossed in.
As for oscillating cosmologies, I am unaware of any work in the area. The
current going opinion is that there is not enough mass to close the universe,
so it is open, and wil expand forever.
You might be interested in a fascinating paper on the subject, "Time Without
End: Physics and biology in an open universe" by Freeman J. Dyson, in Reviews
of Modern Physics, vol. 51, no. 3, July, 1979, pp 447-460. Dyson points out
that the interesting time scales in an open universe are very long. For
instance, stars "evaporate" from galaxies in on the order of 10**19 years. Even
in an open universe, we have a lot of time to play around.
---
------------------------------------------------------------
Timothy J. Thompson, Earth and Space Sciences Division, JPL.
Assistant Administrator, Division Science Computing Network.
Secretary, Los Angeles Astronomical Society.
Member, BOD, Mount Wilson Observatory Association.
INTERnet/BITnet: tjt@scn1.jpl.nasa.gov
NSI/DECnet: jplsc8::tim
SCREAMnet: YO!! TIM!!
GPSnet: 118:10:22.85 W by 34:11:58.27 N
==================================================================
] Basic summary of the first:
] In 1929 Hubble observed that the universe was expanding in all directions.
] The conclusion from that was that at some point in the past, the ENTIRE
] KNOWN UNIVERSE WAS CONTRACTED DOWN TO A SINGLE POINT, from which is has been
] expanding ever since. [emphasis his]
If he managed to draw this conclusion solely from this fact, then I'm
already underwhelmed with his powers of deduction. If all you know is
that the universe appears to be expanding at this time, then there are
still myriad possibilities open--one of them being the above hypothesis,
another being a version of the steady-state model in which everything is
expanding and new matter is being continuously introduced to keep the
average density of space a constant, another being that the known
universe has been expanding from an "original" finite and nonzero size,
and yet another being that all matter is constantly shrinking with
corresponding modifications of physical constants to make everything
appear as it does. Now, at this time it certainly looks like the "big
bang" theory is the one that best fits the available evidence, but not
only does it take a lot more evidence than observations suggesting an
expanding universe, it also doesn't require the known universe ever to
have been contracted down to a single point.
] So, if you go far enough back, the
] universe finally reaces a point of infinite density (ie. nothingness. If
] something were there, it wouldn't be infinite density)
I don't understand the logic behind this at all. It may be worth noting
that many popular theories of quantum behavior posit that leptons
(electrons, muons, taus, and their associated neutrinos) and quarks are
dimensionless points themselves. Following the reasoning above, quantum
electrodynamics would imply that electrons don't exist, an idea that
much of the scientific community would be inclined to dispute.
] He then notes that
] this disturbed many scientists, as it was too close to the Christian idea
] of the creation of something from nothing for comfort.
I seriously doubt that any scientist actually had this particular
feeling. While the "big bang" model was doubtlessly found aesthetically
and emotionally unappealing by some, it is extremely unlikely that
anybody held reservations about the model because it was too close to
Craig's opinion of what "christian ideas" are.
] So, he looks at the
] two alternatives, the steady state model and the oscillating model.
]
] He discredits the steady state model (and quotes from physicist Jaki here,
] any idea what his reputation is?) through the existence of background radiation
] which indicates the universe was once in a very hot and very dense state. In
] the steady state model, no such state could have existed. "According to
] Ivan King, 'The steady-state theory has now been laid to rest, as a result
] of clear-cut observations of how things have changed with time.'"
]
] Question: Is this summary a valid disproof of the steady-state model?
No. The cosmic background radiation is pretty good evidence in favor of
the big bang model and against the steady state model, but I don't think
it qualifies as a "disproof"--indeed, I'd be surprised if some of
steady-state's more stalwart adherents hadn't come up with several
steady-state models that were consistent with the cosmic background
radiation. While big bang is certainly ahead in the polls, I don't
think we can claim that all steady state models have been disproven.
] Then he goes on to attack the oscillating model. He says that the key question
] is whether or not the univese is open or closed. If it is closed, then the
] expansion will reach a certain point, and then the force of gravity will
] pull everything together again. (note that he is not speaking of
] thermodynamically closed here. That's later) But if the universe is open,
] then the expansion will never stop, but will just go on and on forever.
] "Scientific evidence seems to indicate that the universe is open. The crucial
] factor here is the density of the universe. Scientists have estimated that
] if there are more than about three hydrogen atoms per cubic meter on the
] average throughout the universe, then the universe would be closed. That
] may not sound like very much, but remember that most of the universe is just
] empty space. I shall not go into all the technicalities of how scientists
] measure the density of the universe, but let me simply report their
] conclustions. According to the evidence, the universe would have to be at
] least ten times denser than it is for the universe to be closed.
Or, if we wanted to be accurate, the universe would have to contain at
least ten times current estimates of visible matter in the universe.
"Dark matter" such as neutrinos produced during the big bang,
nonluminous gas and dust, yet undiscovered particles, and/or black holes
could all quite possibly contain more than enough mass to close the
universe.
] Therefore,
] the universe is open by a wide margin. Let me share with you the conclusion
] of Alan Sandage: (1) The universe is open, (2) the expansion will not reverse,
] (3) THE UNIVERSE HAS HAPPENED ONLY ONCE and the expansion will never stop."
] "The evidence therefore appears to rule out the oscillating model, since it
] requires a closed universe. But just to drive the point home, let me add that
] the oscillating model of the universe is only a theoretical possibility, not
] a real possibility. As Dr. Tinsley of Yale observes, in oscillating models
] ' even though the mathematics SAYS that the universe oscillates, there is
] no known physics to reverse the collapse and bounce back to a new expansion.
] The physics seems to say that those models start from the big bang, expand,
] collapse, then end.'"
I can't really comment on this one except to say that our understanding
of the forces and interactions that would occur at or near the times of
the big bang or big crunch is very limited--the physical conditions are
just not like anything you can simulate or test in a laboratory and work
on grand unified field theories is still very young. Since we currently
know very little about the physical principles that would operate under
such conditions, I don't think that Dr. Tinsley's quote drives a stake
through the heart of the oscillating model--and, given how it's worded,
I suspect that he doesn't think that it does either.
] Ok, there's the first argument. The second one deals with thermodynamics.
] First the author goes through a fairly good summary of the basic principles
] of entropy and heat death and so on. Actually, rereading this, the second
] argument rests on the conclusions of the first, so the evaluation of the
] above would be nice. HOWEVER, he says that "as several scientists have pointed
] out, each time the model universe expands it would expand a little further
] than before. Therefore, ir you traced the expansions back in time they would
] get smaller and smaller and smaller. Therefore, in the words of one
] scientific team, "The multicycle model has an infinite future, but only a
] finite past." As yet another writer points out, this implies that the
] oscillating model of the universe still requires an origin of the universe
] prior to the smallest cycle."
But is this, in fact, predicted by every oscillating universe model or
just some of them? (Also, since the "laws" of thermodynamics are
statistical abstractions operating under "normal" conditions rather than
physical laws in the way that conservation of mass is, can we be sure
they would apply under big bang and big crunch conditions--indeed, can
we even be sure that conservation laws are still meaningful under those
conditions?)
] So, there it is. Are these logical, scientific conclusions or theological
] propoganda? With reasons, please, and references, if you can. Or, if you
] are unable to tell me the answer, could you direct me to someone who would
] know?
From what you've written here, it sounds like Craig is given to taking
great leaps of logic to his desired conclusions, regardless of how many
other possibilities the evidence points to as well. The logic seems to
be more sleight-of-hand and bold assertion than a genuine effort to
analyze the evidence, so I would suggest reading the book closely and
never taking Craig's word on whether his premises really imply his
conclusions.
Trygve
