Re: [asa] historical versus experimental sciences - resend

That is interesting.   Another moment of closeness, but no cigarness. :)
 
"Coope"
 

--- On Sat, 7/11/09, George Murphy <GMURPHY10@neo.rr.com> wrote:

From: George Murphy <GMURPHY10@neo.rr.com>
Subject: Re: [asa] historical versus experimental sciences - resend
To: "George Cooper" <georgecooper@sbcglobal.net>, "ASA" <asa@calvin.edu>
Date: Saturday, July 11, 2009, 11:31 AM


Another historical point worth noting is that there was evidence for the MWB before its detection in the 60s.  In 1941 McKellar found that the absorption spectrum of CN in some interstellar clouds indicated that the molecules were at a temperature of ~2.3K.  (I.e., the 1st excited rotational state was populated to this extent.)  After the discovery of the microwave radiation by Penzias & Wilkinson it was realized that this earlier observation was seeing the effect of the radiation at a shorter wavelength.  Weinberg gives more detail on this & related measurements in Gravitation and Cosmology, pp.512-515.
 
Shalom
George
http://home.roadrunner.com/~scitheologyglm

----- Original Message -----
From: George Cooper
To: ASA
Sent: Saturday, July 11, 2009 11:06 AM
Subject: Re: [asa] historical versus experimental sciences - resend

Regarding the CMBR as it relates to the BBT, it is interesting to note that this ubiquitous radiation was a prediction of the theory, which became a very powerful argument for favoring BBT.  Further, the CMBR contained additional powerful support from the information discovered within the CMBR: the degree of isotropy and anisotropy, power spectrum, the dipole, etc.  All objective evidence supporting the theory in a very impressive way. 
 
"Coope"
 

--- On Sat, 7/11/09, George Murphy <GMURPHY10@neo.rr.com> wrote:

From: George Murphy <GMURPHY10@neo.rr.com>
Subject: Re: [asa] historical versus experimental sciences - resend
To: "George Murphy" <GMURPHY10@neo.rr.com>, "Cameron Wybrow" <wybrowc@sympatico.ca>, "asa" <asa@calvin.edu>
Date: Saturday, July 11, 2009, 6:36 AM

This from last evening doesn't seem to have gotten to the list so ....
 
Cameron -
 

You're right that the "remnant radiation from the big bang" is a theoretical inference from observations of the microwave background.  But "historical" data are not unique in this regard.  When particle physicists say that they've "observed" the top quark, e.g., that's really a theoretical inference from knowledge of the particles involved in collisions (itself a theoretical inference), electronic signals from detectors &c.  Again, there's no sharp distinction between historical & experimental sciences.

On supposed "patches" of current cosmological theory, you have to realize that "big bang theory" is a very broad term that really covers a wide variety of cosmological models.  "Hot big bang" means just that the universe was once in a much denser & hotter state than it is now & has been expanding & cooling down since that time.  That model is what now seems quite well supported by data - galactic recession, MWB & light element abundances - & basic physical theories such as general relativity, thermodynamics, & nuclear & electromagnetic theory.  But general relativity allows for a huge number of such models.  The discovery that expansion seems to be accelerating, e.g., came as a big surprise but in fact fits models of general relativity with a cosmological term (which, contrary to many statements, is no mere "fudge factor"), & in any case doesn't challenge the basic "hot big bang" scenario. 

Most of the modifications of BB theory that you hear about don't involve getting rid of that scenario but are attempts to penetrate into the first fractions of a second of expansion - i.e., in a sense to provide a more detailed picture of the "bang" itself.  (The first physics paper I published, in 1972, was in this category, as is my most recent a couple of years ago.  Or they may be trying to get back before the big bang.  Some of these theories are motivated by observations & some are clearly attempts to get rid of what looks to some disturbingly like a "moment of creation."  But since the 2.7K background confirmed a prediction of hot BB theory the steady state theory & other competitors of the BB have found few competent defenders.  There are still a few diehard steady state people but they're sort of like those news stories that appeared occasionally in the 50s & 60s of Japanese soldiers on Pacific Islands who didn't realize that the
 war was over. 

Theories of biological evolution have to do primarily with the development of the biosphere over relatively long time scales, & the ability of modern evolutionary theory to make sense of data having to do with that development is the major point in its favor.  But I think you underestimate its significance for day to day biological science.  In the July issue of Physics Today that just came in the mail there’s a short article “Analysis reveals when evolution favors one mode of gene regulation over another.”  The point there isn’t that evolution predicted a particular laboratory result but that it allows geneticists to make sense of what they found.  Score one more for Dobzhansky.

Shalom
George
http://home.roadrunner.com/~scitheologyglm

To unsubscribe, send a message to majordomo@calvin.edu with
"unsubscribe asa" (no quotes) as the body of the message.
Received on Sat Jul 11 15:25:29 2009