Is Veizer and Shaviv's GCR Theory Accepted in Mainstream Science?

  • Thread starter Thread starter Norman
  • Start date Start date
  • Tags Tags
    Science
Click For Summary

Discussion Overview

The discussion revolves around the acceptance of Veizer and Shaviv's Galactic Cosmic Ray (GCR) theory within mainstream science, particularly in relation to geological and atmospheric studies. Participants explore the implications of the theory, critiques of the original paper, and the validity of the claims made regarding cosmic ray flux and its effects.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant, a particle physicist, questions whether Veizer and Shaviv's work is considered mainstream and if there is any refutation or consensus regarding their claims.
  • Another participant suggests that the GCR power density variability might be significant and critiques the assumption that cosmic ray flux is negligible compared to solar flux.
  • A participant provides a link to a free version of the Veizer and Shaviv paper, indicating accessibility issues with the original source.
  • One participant shares a critique of the original paper, highlighting concerns about the validity of using meteorite clusters to infer cosmic ray flux variability and the appropriateness of regression analysis over different time scales.
  • Another participant discusses the potential relationship between cosmic ray ionization, cloud cover, and solar activity, suggesting that changes in cosmic ray flux could partially explain discrepancies in temperature records.

Areas of Agreement / Disagreement

Participants express differing views on the validity of Veizer and Shaviv's claims and the critiques of their work. There is no consensus on whether the theory is accepted in mainstream science, and multiple competing perspectives are present.

Contextual Notes

Some limitations are noted regarding the assumptions made in the critiques, particularly concerning the time scales used in the analysis and the interpretation of cosmic ray data.

Norman
Messages
895
Reaction score
4
Hi all,

I am a particle physicist who deals with transport of radiation through materials. That is to say I am directly involved with the shielding of astronauts from galactic cosmic rays. I came across a paper a paper that said the http://www.gsajournals.org/gsaonline/?request=get-abstract&doi=10.1130%2F1052-5173(2003)013%3C0004:CDOPC%3E2.0.CO%3B2[".
It is a paper by Veizer and Shaviv that looks at geological records and compares them to some models of the GCR spectrum.

My question is, is this considered main stream science? That is to say, has there been any work that refutes this or superceedes it? Has a consensus in the atmospheric and geological realms been reached on the validity of their statements? Admittedly, I have not read the paper in detail, just a quick skim. I will withold any more comments until the people who are more knowledgeable than me in this realm comment.
Cheers,
Ryan
 
Last edited by a moderator:
Earth sciences news on Phys.org
"Somewhat?" Can't argue with a word like that --- (1/T)dT ~ (1/4q"dot")dq"dot". If they come up with a GCR power density variability of tenths of watts, no one can argue --- it's more rigorous bookkeeping than assuming, "The cosmic ray flux" is insignificant when compared to the solar flux.

Comment on the link: if it's a "subscribers only" site, include a brief summary of the pertinent information, such as "Found a GCR flux of x watt/m2.

Edit: Sorry 'bout the missing "(1/T)" --- now corrected.
 
Last edited:
Sorry didn't realize it was subscriber only... I could access so I didn't think of it. Still haven't had a chance to read it thoroughly.

The paper can be found for free http://www.envirotruth.org/docs/Veizer-Shaviv.pdf"
 
Last edited by a moderator:
Here is a good critique of the previous paper.
http://www.soest.hawaii.edu/GG/FACULTY/POPP/Rahmstorf%20et%20al.%202004%20EOS.pdf"

The critique finds two main problems with the article.

First. The fact that meteorite cluster can give information about the cosmic ray flux variability seems dubious. The original article draws some conclusions that don't seem to be reasonable, especially about the movement through the 4 galactic arms being so unperiodic.

Second. They use a very simple regression analysis which assumes variation on the scale of millions of years. The use of this on time scales of decades or centuries is a little questionable they contend (and I agree with).
 
Last edited by a moderator:
Okay, learn sumpin' every day --- cosmic ray ionization of troposphere leads to increased cloud cover. From there we move to correlation of high CRF (cosmic ray flux) with reduced solar "constant" (less shielding), and the suggestion that the discrepancy between changes in solar "constant" and change in global mean temperature as derived from meteorological records ("gray body" effect of 2-4 watt increase over past century suggests 0.15 - 0.3 K increase compared to an unreviewed increase of 0.6 K in screen height air temperature measurements) can be explained, at least partly, by reduced cloud cover resulting from lower CRF due to increased solar activity.

That the way you read their "problem" statement, Norman? Don't wanta get too far gone critiquing their treatments or the critics' assessments 'til we're on the same page.