RE: [asa] Theory of gravity

One interesting point that was mentioned in the PBS show was that "theory"
is much more powerful and interesting in science that "fact". The facts are
observed things; a bone here, a fossil there, an action (e.g. gravity)
working in a certain way. But a scientific theory is what takes these
discrete observations and disconnected facts, and draws a grand picture, a
universal explanation, a set of describing equations, etc.
 
This is opposite of the common perception that "facts" are more important
than theories. As the popular saying goes, "evolution is a theory, not a
fact." But that's not true in the scientific sense, as you say a
"smokescreen", confusing popular and scientific terminology. There are
facts (fossil record, DNA evidence, observations of trait inheritance), and
there are theories ("random" mutation, natural selection, gene transfer, DNA
splicing, copying errors, now possibly epigenetics) to explain those facts
and tie them together. I may not be comfortable with some of the present
theories, but the facts can't just be easily dismissed. And, considering
the nature of scientific discovery and the present state of knowledge, I
don't see any reason why there couldn't be discovered a "grand covering
theory" for much of the current theory of evolution. I would dare say
intelligent design (if not the Intelligent Design Movement) could claim to
be such a covering theory, but given the analogy with Einstein I don't know
why one would expect the covering theory to all of a sudden be an overtly
supernatural one. Most modern Christians who know anything about Einstein
don't consider relativity to be a threat to the idea that God is in and
through all things, and the Creator of all.
 
 
Jon Tandy
 <http://www.arcom.com/>

-----Original Message-----
From: George Murphy [mailto:gmurphy@raex.com]
Sent: Wednesday, November 21, 2007 7:17 AM
To: Jon Tandy; 'ASA'
Subject: Re: [asa] Theory of gravity

IMO one can worry too much about what to label a "law," what a "theory" &c.
"Gravity" is a fact in the sense that things fall to the earth. Newton's
theory included the claim that this was a universal property of matter (&
not just the earth) described by the inverse square law. He declined,
however, to make any definite statement on the cause of gravity - i.e., to
give any deeper explanation of why masses attract that way. Newton's theory
was good in the sense that it explained a lot of data & predicted others,
but Einstein's theory is better (i.e., explains & predicts more things), in
part because it goes deeper into the cause of the phenomena by connecting
the presence of matter & space-time geometry. Thus Einstein's is a
"covering theory" for Newton's. But it isn't perfect - it can be shown that
a quantum theory of gravitation is a necessity, even though we have no
actual observational discord with Einstein's classical theory.
 
Interestingly, while people do refer to Newton's F = -GMm/r^2 as a "law" of
gravitation, I have seldom seen Einstein's R^mn - (1/2)Rg^mn = - 8piT^mn
called a "law" - in spite of the fact that the latter agrees better with
oberservations. It's just "Einstein's field equations." So much for the
precision of these terms!
 
Evolution as a fact is not quite as well established as the fact that things
fall downward but it's close. I.e., without a lot of very special pleading,
the the fossil record & other data show that there has been widespread
descent with modification. Darwin & Wallace provided an explanation - a
theory - for how this has happened. Like Newton's theory it is well
supported but not perfect. In this case, however, necessary corrections may
be minor touch-ups rather than a grand covering theory a la Einstein.
 
I think a lot of the "fact - theory - law" rhetoric is just
anti-evolutionist smokescreen.
 
Shalom
George
http://web.raex.com/~gmurphy/

----- Original Message -----
From: Jon <mailto:tandyland@earthlink.net> Tandy
To: 'ASA' <mailto:asa@calvin.edu>
Sent: Wednesday, November 21, 2007 7:23 AM
Subject: [asa] Theory of gravity

Having now finally watched the rest of the PBS special on the Dover trial, I
have a few questions. I'll just start with one for now.
 
I recall it being mentioned that the "theory of gravity" is the same as the
"theory of evolution" -- both are tentative and could potentially be
disproved, although both have substantially large bodies of evidence in
support of them. I thought that was a good argument at the time, but later
I imagined that someone will criticize that argument on the grounds that
Newton's "laws" are no longer considered scientific theory but laws. As an
example of the confusion of terms, Wikipedia's article "Newton's law of
universal gravitation"
(http://en.wikipedia.org/wiki/Newton%E2%80%99s_law_of_gravitation) starts
with the statement: "Isaac Newton's THEORY of universal gravitation is a
physical LAW describing the gravitational attraction between bodies with
mass."
 
As someone with a fair amount of education in science, I realized I didn't
have a completely solid grasp of the difference between a law and a theory.
My first thought was a law is more sufficiently proven or demonstrated than
a theory. However, on reflection, I think a better explanation is that a
scientific law attempts to describe an observation in nature with
empirically derived analytical formulas, while a scientific theory attempts
to explain the observations (causes, etc.). So is gravity a law or a
theory? If I'm not mistaken, it's both. The law of gravity (Newton's
generalization, now superceded by Einstein's equations) is given by
F=G(m1*m2)/r^2. This is empirically derived and demonstrable (again, with
qualification by Einstein in special cases). However, the theory of gravity
seeks explanation by proposing the source of the force of gravity, such as
gravitons, etc., which is still in the theoretical stages, with various
alternative proposals. Is this a fair assessment? Is it true that
gravitation, or at least some aspect of it, is still "only a theory" (to use
derogatory YEC-speak)?
 
The "theory of evolution" attempts to explain the mechanisms of observed
phenemona. It's clear that this is still a theory in flux, with new
discoveries such as lateral gene transfer, DNA replication errors, etc.,
contributing to biological development in ways not completely understood.
But if a "scientific law" describes observations in nature, at what point
could the observations of evolutionary inheritance be called a "law"? Could
there come a point where certain observations or mechanisms of biological
evolution could become quantified to an extent like Newton's formula for the
law of gravity? Is it there yet? I don't know of anyone using the
terminology "law of evolution" on either side of the debate, although there
was something (either in the program or in a forum discussion on our local
PBS station after the program), where the assertion was made by ID advocates
that "evolution is not the 'law of evolution', but only the 'theory of
evolution' ".
 
 
Jon Tandy
 

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Received on Wed Nov 21 09:09:17 2007