From 34afc48993c57efa3d94f2adef6db15bf76c36aa Mon Sep 17 00:00:00 2001 From: kuahyeow Date: Sat, 17 Jul 2010 23:02:20 +1200 Subject: [PATCH] Elements were not all created during the Big Bang --- gamow.txt | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/gamow.txt b/gamow.txt index 7cc8f7c..14f2d21 100644 --- a/gamow.txt +++ b/gamow.txt @@ -1,4 +1,6 @@ http://en.wikipedia.org/wiki/Alpher–Bethe–Gamow_paper + + In physical cosmology, the Alpher–Bethe–Gamow paper, or αβγ paper, was created by Ralph Alpher, then a physics PhD student, and his advisor George Gamow. The work, which would become the subject of Alpher's PhD dissertation, argued that the Big Bang would create hydrogen, helium and heavier elements in the correct proportions to explain their abundance in the early universe. While the original theory neglected a number of processes important to the formation of heavy elements, subsequent developments showed that Big Bang nucleosynthesis is consistent with the observed constraints on all primordial elements. Gamow humorously decided to add the name of his friend—the eminent physicist Hans Bethe—to this paper in order to create the whimsical author list of Alpher, Bethe, Gamow, a play on the Greek letters α, β, and γ (alpha, beta, gamma). Bethe was listed in the article as "H. Bethe, Cornell University, Ithaca, New York." In his 1952 book, The Creation of the Universe, Gamow explained Hans Bethe's association with the theory thus: @@ -6,7 +8,9 @@ Gamow humorously decided to add the name of his friend—the eminent physicist H Alpher, at the time only a graduate student, was generally dismayed by the inclusion of Bethe's name on this paper. He felt that the inclusion of another eminent physicist would overshadow his personal contribution to this work and prevent him from receiving proper recognition for such an important discovery. He expressed resentment over Gamow's decision as late as 1999.[ The theory originally proposed that all atomic nuclei are produced by the successive capture of neutrons, one mass unit at a time. However, later study challenged the universality of the successive capture theory. No element was found to have a stable isotope with an atomic mass of five or eight. Physicists soon noticed that these mass gaps would hinder the production of elements beyond helium. Just as it's impossible to climb a staircase one step at a time when one of the steps is missing, this discovery meant that the successive capture theory could not account for higher elements. -It was eventually recognized that most of the heavy elements observed in the present universe are the result of stellar nucleosynthesis in stars, a theory largely developed by Bethe. + +http://en.wikipedia.org/wiki/Stellar_nucleosynthesis +Stellar nucleosynthesis is the collective term for the nuclear reactions taking place in stars to build the nuclei of the elements heavier than hydrogen. Some small quantity of these reactions also occur on the stellar surface under various circumstances. For the creation of elements during the explosion of a star, the term supernova nucleosynthesis is used. Text is available under the Creative Commons Attribution-ShareAlike License; additional terms may apply. See Terms of Use for details. http://creativecommons.org/licenses/by-sa/3.0/