by Livio, Mario
“Only the inertia of tradition”: Eddington 1920. Quoted also in full in the 1988 edition of The Internal Constitution of the Stars (Cambridge: Cambridge University Press), in the foreword (by S. Chandrasekhar), p. x.
the strong, attractive nuclear force: At distances that are very small compared to the size of the nucleus, the nuclear force itself becomes repulsive, because particles such as protons (fermions) resist being crowded. This quantum effect is known as the Pauli exclusion principle.
Using this quantum mechanical effect: The probability of penetrating the barrier created by the Coulomb force increases exponentially with increasing energy of the particles. At the same time, the distribution of the particles at a given temperature is such that at high energies the number of particles decreases exponentially. The product of these two factors results in a peak (known as the Gamow peak) at which the nuclear reaction is most likely to occur. These ideas were first published in the late 1920s.
In a remarkable paper published: Bethe 1939.
the proton-proton (p-p) chain: For those with some nuclear physics background, the two main channels contributing to the energy production in the Sun are the pp I branch: p + p → D + e+ + νe, D + p → 3He + γ, 3He + 3He → 4He + 2p, and the pp II branch: 3He + 4He → 7Be + γ, 7Be + e- → 7Li + νe, 7Li + p → 24He.
“There is no way in which nuclei”: Bethe 1939, p. 446.
the results were published in the April 1: Alpher, Bethe, and Gamow 1948. Gamow had already presented the idea of nucleosynthesis in the big bang in Gamow 1942 and Gamow 1946.
often referred to as the “alphabetical article”: In his book The Creation of the Universe, Gamow jokes “There was, however, a rumor that later, when the α, β, γ theory went temporarily on the rocks, Dr. Bethe seriously considered changing his name to Zacharias” (Gamow 1961, p. 64).
“stubbornly refuses to change his name”: Gamow 1961, p. 64.
Even the great physicist Enrico Fermi: Fermi examined the problem together with physicist Anthony Turkevich, even though they never published their results. A good description of the work on the mass gap problem can be found in Kragh 1996, pp. 128–32.
was an epoch-making paper: Hoyle 1946.
“I sat in the RAS auditorium”: Hoyle made the presentation on November 8, 1946. Margaret Burbidge was at the time Margaret Peachey; she was to marry astronomer Geoffrey Burbidge in 1948. The quote is from a lecture Margaret Burbidge gave at St. John’s College, Cambridge, on April 16, 2002. An excellent popular description of Hoyle’s work on nucleosynthesis can be found in Mitton 2005, chapter 8.
that particular student decided to ditch: The incident is described in Hoyle 1986b.
Ernst Öpik proposed in 1951: Öpik 1951.
Salpeter examined the triple alpha process: Salpeter 1952. (Also Bondi and Salpeter 1952.) Salpeter went on to have a distinguished career in astrophysics.
“Bad luck for poor old Ed”: Hoyle 1982, p. 3.
“had to go a lot faster”: Hoyle 1982, p. 3.
Hoyle calculated that for carbon production: While there had been some earlier suggestions for resonances around 7.4 MeV or so, those had never been confirmed, and in any case, no resonant level had been suggested (before Hoyle’s prediction) above 7.5 MeV.
What happened at that meeting: After many years, the participants had somewhat different recollections of the events. A good summary of the various versions can be found in Kragh 2010.
“Here was this funny little man”: Interview by Charles Weiner, American Institute of Physics, in February 1973. Cited in Kragh 2010.
“To my surprise, Willy didn’t”: Hoyle 1982, p. 3.
Ward Whaling and his colleagues: Described also in Fowler’s Nobel lecture, “Experimental and Theoretical Nuclear Astrophysics; the Quest for the Origin of the Elements,” given on December 8, 1983.
In their just-over-one-page: Dunbar, Pixley, Wenzel, and Whaling 1953. The paper and its significance is described also in Spear 2002.
Despite his amazingly successful prediction: Given that life as we know it is carbon based, much has been made of the anthropic significance of the resonant level in carbon. This issue is beyond the scope of the discussion here. I should note that in 1989, I, along with colleagues, showed that even if that energy level had been at a slightly different value, stars still would have produced carbon (Livio et al. 1989). This conclusion was confirmed later by more detailed work by Heinz Oberhummer and colleagues (Schlattl et al. 2004). For a detailed review, see Kragh 2010.
more than a half year passed: Hoyle et al. 1953.
“In a sense this was but a minor”: Hoyle 1986b, p. 449.
“In the beginning God created”: Gamow 1970, p. 127. Gamow really wanted to express his objections to the steady state theory (discussed in chapter 9) proposed by Hoyle, Bondi, and Gold, but he ended up nevertheless acknowledging Hoyle’s contribution.
“Perhaps his [Hoyle’s] most important”: Crafoord Prize 1997 press release.
In this paper, published in 1954: Hoyle 1954.
The 1957 landmark paper: Burbidge, Burbidge, Fowler, and Hoyle 1957. A very lively, popular account of the history of the theory of nucleosynthesis is Chown 2001. Tyson and Goldsmith 2004 provide a clear, humorous, multidisciplinary tour of cosmic evolution, from cosmology to biology.
Both Fowler and Hoyle presented their results: Hoyle 1958, p. 279; Fowler 1958, p. 269.
a summary of the entire meeting: Hoyle 1958, p. 431.
felt that Hoyle should have also: For an online discussion of the issue of Hoyle’s not winning the Nobel Prize, see, eg, www.thelonggoodread.com/2010/10/08/fred-hoyle-the-scientist-whose-rudeness-cost-him-a-nobel-prize.
“The theory of stellar nucleosynthesis”: Burbidge 2008. Nuclear astrophysicist Donald Clayton also explained the enormous significance of Hoyle’s 1954 paper; Clayton 2007.
“I also discovered that I had”: Cited in Burbidge 2003, p. 218.
and these collaborative exchanges: Described beautifully in an interview with Tommy Gold by historian of science Spencer Weart. The interview took place on April 1, 1978, for the American Institute of Physics.
Hoyle suggested cosmology as the topic: Described in a fascinating interview with Fred Hoyle, in Lightman and Brawer 1990, p. 55.
Chapter 9: The Same Throughout Eternity?
“not only the laws of nature”: Milne 1933.
“In a sense, the steady-state”: Hoyle 1990. In his excellent account of the history of the steady state theory, Kragh 1996 raised doubts about the authenticity of the film story. However, shortly after the New York Times reported (on May 24, 1952) on a lecture by the Astronomer Royal, Sir Harold Spencer Jones, Hoyle wrote him a letter in which he specifically mentioned the film story. The fact that this letter was written as early as 1952 gives this account more credibility.
“What happened was that there was”: Weart 1978.
in a paper published in 1929: Hubble 1929a.
the Russian mathematician Aleksandr Friedmann: Friedmann 1922.
a passionate debate flared up: A few of the articles about the credit for the discovery of cosmic expansion are Way and Nussbaumer 2011, Nussbaumer and Bieri 2011, Van den Bergh 2011, and Block 2011.
astronomer Vesto Slipher had measured: Described, eg, in Van den Bergh 1997.
Arthur Eddington listed those: Eddington 1923, p. 162.
Georges Lemaître published (in French) a remarkable paper: Lemaître 1927.
from brightness measurements by Hubble: Hubble 1926.
Edwin Hubble obtained a value: Hubble 1929a.
Based solely on what I have described: A brief summary of the events can be found in Livio 2011. See also Nussbaumer and Bieri 2009, Kragh and Smith 2003, and Trimble 2012 for more detailed descriptions.
The English translation of Lemaître’s: Lemaître 1931a.
Canadian astronomer Sidney van den Bergh: Van den Bergh 2011.
David Block went even somewhat further: Block 2011.
First, I obtained
a copy: I am grateful to the Archives Georges Lemaître in Louvain, Belgium, and to Mme. Liliane Moens for providing me with a copy.
any intent of extra editing: Block thought that the “©©1–n” in the letter should be read as “©©1–72” because of the way the symbol “n” was written. He also interpreted the text as saying that Lemaître was given freedom to translate only the first seventy-two paragraphs of his paper. He further concluded that paragraph seventy-three was precisely Lemaître’s equation determining the value of the Hubble constant. None of these was convincing. (See Livio 2011 for a discussion.)
in the minutes of the council: RAS 1931.
The second piece of evidence: RAS, RAS correspondence 1931.
“The Expanding Universe”: Lemaître 1931b.
“Dinner was a little late”: Bondi 1990, p. 191.
Bondi and Gold proposed their Perfect Cosmological Principle: Bondi and Gold 1948.
Hoyle embarked on a more mathematical: Hoyle 1948a.
“causes unknown to science”: Hoyle 1948a.
“Neutron creation appears to be the most likely”: Hoyle 1948a.
“I shall not require of a scientific”: Popper 2006, p. 18.
“Modern astrophysics appears to be”: Hoyle 1948b, p. 216.
“Cosmology is one department of astronomy”: Greaves 1948, p. 216.
“I am overawed by the whole”: Born 1948, p. 217.
“inferior and detestable species”: Hoyle 1994, p. 270.
one in the New York Times: Appeared on May 24, 1952. The article in the Christian Science Monitor appeared on June 7, 1952.
he and his student John Shakeshaft: Described in the Proceedings of Meeting of the Royal Astronomical Society 886, pp. 104–6.
“glad to see that there is now”: Gold 1955.
Bondi was also skeptical: Bondi 1955.
“Was I being uncharitable in thinking”: Hoyle 1994, p. 410.
The discovery of extremely active galaxies: For an excellent popular description of the discovery of quasars, of the microwave background, and their significance see, eg, Rees 1997.
could all still be explained: Hoyle 1990.
he published a book entitled: Hoyle, Burbidge, and Narlikar 2000. Livio 2000 is a review of the book.
Narlikar suggested that Hoyle’s: Interview with the author on March 5, 2012.
Eggleton remembered Hoyle as a person: Interview with the author on July 1, 2011.
to describe the Victorian scholar Benjamin Jowett: Jowett was appointed a fellow of Balliol College in Oxford at the age of twenty-one. He was satirized by:
First came I; my name is Jowett.
There’s no knowledge, but I know it.
I am the Master of this college
What I don’t know isn’t knowledge.
Faulkner admitted that he himself: Interview with the author on August 19, 2011. See also Faulkner 2003.
Martin Rees, Astronomer Royal: Interview with the author on September 19, 2011. See also Rees 2001.
“The problem with the scientific”: Hoyle 1994, p. 328.
“From my very youth I despised”: Cited, eg, in Boorstin 1983, p. 345.
Biologist Richard Dawkins labeled: Hoyle’s original argument was against abiogenesis—the theory for the origin of life on Earth—not against Darwin’s theory of evolution. Dawkins expands on the discussion of Hoyle’s fallacy in Dawkins 2006.
Denial seldom evokes sympathy: Kathryn Schulz gives a fascinating discussion of the sentiments involved in being wrong in Schulz 2010.
Physicist Alan Guth proposed inflation: He described the model beautifully in his popular book, Guth 1997.
These are precisely the properties: The relation between the steady state universe and the inflationary universe is discussed by Barrow 2005.
contributed important studies to big bang: In particular, Hoyle and Tayler 1964 and Wagoner, Fowler, and Hoyle 1967.
Chapter 10: The “Biggest Blunder”
Einstein himself first attempted: Einstein 1917.
Edwin Hubble confirmed unambiguously: The definitive results were published in Hubble 1929b.
“That term is necessary only”: Einstein 1917, p. 188 in the English translation.
he modified his equations in such: For the mathematically inclined, the original equations were: Gμν = 8πG Tμν, where G is the gravitational constant, Tμν is the stress-energy tensor, and Gμν is Einstein’s curvature tensor representing the geometry of space-time. The modified equations were: Gμν – 8πG ρΛ gμν = 8πG Tμν, where ρΛ could be taken as an energy density associated with the cosmological constant, and gμν is the space-time tensor that defines distances.
Eddington was the first to point out: Eddington 1930.
Einstein insisted that the distribution of matter: Einstein relied here on what is known as Mach’s principle, after Austrian physicist and philosopher Ernst Mach, who suggested that motion and acceleration cannot be felt at all in an empty universe. An excellent discussion on the modern interpretation of Mach’s principle can be found in Greene 2004.
In his theory of special relativity: There are many good popular books describing special and general relativity. Two that I found particularly engaging are Kaku 2004 and Galison 2003. Reading Einstein 2005 is always rewarding. In Tyson’s witty 2007 collection of essays, he tackles many related topics beautifully.
even for relative speeds as low: Chou, Hume, Rosenband, and Wineland 2010.
The theory was based largely: Einstein himself explained the principles in Einstein 1955. Hawking 2007 presents a collection of Einstein’s papers. In the scientific biography of Einstein, Pais 1982 explains the principles beautifully. Greene 2004 puts the theory in layperson’s terms in the context of modern developments.
“If a person falls freely”: The Kyoto Lecture was delivered on December 14, 1922. It was translated into English by Y. A. Ono, from notes taken by Yon Ishiwara (Physics Today, August 1932).
the deviations recorded by his team: The results were described in Dyson, Eddington, and Davidson 1920.
Experiments have confirmed this effect: New generations of clocks continuously improve the accuracy; eg, Tino et al. 2007.
there were a few theoretical disappointments: Earman 2001 gives a detailed, excellent (technical) discussion of Einstein’s introduction of the cosmological constant and its early history. A clear exposition is also North 1965 (see also Norton 2000).
Willem de Sitter found a solution: de Sitter 1917.
“If there is no quasi-static world”: Einstein’s letter to Weyl on May 23, 1923.
In a paper published in 1931: Einstein 1931.
in a paper Einstein published together: Einstein and de Sitter 1932.
In an article entitled “The Evolutionary Universe”: Gamow 1956.
in his autobiographical book: Gamow 1970, p. 44.
“Einstein would meet me in his study”: Gamow 1970, p. 149.
in his book Ordinary Geniuses: Segrè 2011, p. 155.
Albrecht Fölsing, who wrote one: Fölsing 1997.
he inquired with the army: The entire episode is described in Brunauer 1986.
Gamow asked for Einstein’s opinion: Letter written on September 24, 1946. Document 11-331 in the Albert Einstein Archives.
Gamow attached his paper: Letter written on July 9, 1948. Documents 11-333 and 11-334 in the Albert Einstein Archives.
Einstein replied politely to Gamow’s: Eg., on August 4, 1948. Document 11-335 in the Albert Einstein Archives.
Einstein’s letter of August 4, 1946: Document 70-960 in the Albert Einstein Archives.
any other of his more intimate friends and colleagues: The Physics Department at Princeton University held a symposium on relativity in honor of Einstein’s seventieth birthday. Gamow was among the many who were invited. (A letter from Assistant to the Chairman at Princeton Paul Busse on March 15, 1949, informs him of travel arrangements.) However, Gamow’s name does not appear on the list of people accepting the invitation, from March 1
7, 1949.
“The introduction of the ‘cosmological member’”: Einstein 1955, p. 127.
“If Hubble’s expansion had been discovered”: Einstein 1955, p. 127.
included a supplementary footnote: Pauli 1958, p. 220.
“Our experience up to date”: Einstein 1934, p. 167.
He articulated his feelings in a letter: Letter written on September 26, 1947. Document 15-085.1 in the Albert Einstein Archives.
This was a reply to a letter: In his letter to Einstein on July 30, 1947, Lemaître says that he is making “some effort to modify” Einstein’s attitude against the cosmological constant. Document 15-084.1 in the Albert Einstein Archives.
“Since I have introduced this term”: Einstein’s letter to Lemaître from September 26, 1947. Document 15-085.1 in the Albert Einstein Archives.
Did he think then that this was: Laloë and Pecker 1990 also did not think that Einstein had used this language, but the evidence they presented was much weaker.
The laws of physics thus resemble: This comparison was used also by Weinberg 2005.
University of Manchester astronomer: Leahy 2001.
Einstein has become the embodiment: Among the many biographies of Einstein, I want to mention in particular Isaacson 2007, Fölsing 1997, and a book that presents other aspects of his personality beautifully: Overbye 2000.
Physicist Richard C. Tolman: Letter on September 14, 1931. Document 23-031 in the Albert Einstein Archives.
a universe with a cosmological constant: Lemaître’s ideas about galaxy formation were expressed, eg, in Lemaître 1931b, 1934.
While this particular idea was shown: Brecher and Silk 1969.
“Return to the earlier view”: Eddington 1952, p. 24.
“There are only two ways”: Eddington 1952, p. 25.
The inflationary model: Described beautifully in Guth 1997.
he distinguished presciently between: McCrea 1971.
Chapter 11: Out of Empty Space
Newton was the first to consider: Calder and Lahav 2008 discuss how Newton’s work alludes at least to some aspects of the effects of “dark energy.”