The Perfect Theory (40 page)

[>]
a difficult, open problem that hardly anyone wanted to work on: While Peebles and his contemporaries really established the field of physical cosmology, the idea that there is some fundamental connection between the expanding hot Big Bang model and the formation of galaxies appears first in Lemaître (1934) and Gamow (1948).

[>]
large structures: The ideas leading up to the formation of large-scale structure can be found in Silk (1968), Sachs and Wolfe (1967), Peebles and Yu (1970), and Zel'dovich (1972).

[>]
“No one paid any attention to our paper”: J. Peebles, private communication, 2011.
“stream of galaxies . . . supergalaxy”: G. de Vaucouleurs in Lightman (1988a).
“We have no evidence for the existence”: Ibid.

[>]
“Superclustering is nonexistent”: Ibid.
“good observations are worth more than another mediocre theory”: M. Davis on Peebles in Lightman and Brawer (1990).
“flabbergasted . . . I wrote some pretty vitriolic papers with examples”: J. Peebles in Lightman (1988b).

[>]
“inner space and outer space”: A historic conference on connecting “inner space” and “outer space” was held at Fermilab in 1984 and written up in Kolb et al. (1986).

[>]
“The density of luminous matter”: F. Zwicky in Panek (2011), p. 48.

[>]
“we think it likely that the discovery of invisible matter”: Faber and Gallagher (1979).
“I didn't take it at all seriously”: J. Peebles, private communication, 2011.

[>]
“There was a lot of net casting in the eighties”: J. Peebles in Smeenk (2002).

[>]
Y. Zel'dovich's estimate of the cosmological constant: Zel'dovich (1968).
“We argue here that the successes”: Efstathiou, Sutherland, and Maddox (1990).

[>]
“a universe having critical energy density”: Ostriker and Steinhardt (1995).

“The problem with the choice”: Peebles (1984).
“A non-zero cosmological constant”: Efstathiou, Sutherland, and Maddox (1990).
“requires a seemingly implausible”: Blumenthal, Dekel, and Primack (1988).
“How can we explain the non-zero”: Ostriker and Steinhardt (1995).

[>]
“If you're religious, this is like looking at God”: G. Smoot press conference at Lawrence Berkeley Laboratory, 1992.

[>]
“The findings also appear to breathe”:
Washington Post,
January 9, 1998.
“Exploding Stars Point to a”: Glanz (1998).
“stunned the universe may be accelerating”: CNN, February 27, 1998.
“My own reaction is somewhere between amazement and horror”: B. Schmidt in the
New York Times,
March 3, 1998.

[>]
“The best explanation for what the data”: J. Peebles, private communication, 2011.

[>]
“After a genie is let out of the bottle”: Zel'dovich and Novikov (1971), p. 29.
dark energy: The term
dark energy
was first proposed in Huterer and Turner (1998).

 

12.
THE END OF SPACETIME

 

The modern history of quantum gravity is fraught and fascinating. To get a grand overview, Rovelli (2010) has an appendix with the various major stages, discoveries, and shifts. DeWitt-Morette (2011) describes the genesis of the “Trilogy” and how DeWitt viewed the development of the field. For a hugely successful and articulate summary of string theory, you need to turn to Greene (2000). Yau and Nadis (2010) takes a mathematician's viewpoint of string theory. The alternative paths to quantum gravity, such as loop quantum gravity, are well described in Smolin (2000). The two books that led to the vicious backlash against string theory are Smolin (2006) and Woit (2007). It is worth looking at some of the blogs and following the discussions to see how heated they became. I would look at the following and wind back to when the books were published:

http://blogs.discovermagazine.com/cosmicvariance/

http://asymptotia.com/

http://www.math.columbia.edu/~woit/wordpress/

The black hole information paradox is an ongoing story, and even though I haven't discussed “black hole complementarity,” I highly recommend Susskind (2008) for a personal and energetic account of how the paradox has developed over the years. Solutions are still cropping up: as I was finishing this book, another proposal, “the firewall,” which modifies one of the fundamental tenets of general relativity, was being heatedly debated. For a description of the proposal, see
http://blogs.scientificamerican.com/critical-opalescence/2012/12/14/when-you-fall-into-a-black-hole-how-long-have-you-got/
.

 

[>]
“Is the End in Sight for Theoretical Physics?”: S. Hawking's lecture is published in its entirety in Boslough (1989).

[>]
Hawking's lecture: A colorful description of Hawking's talk can be found in Susskind (2008).

[>]
“Trilogy”: DeWitt-Morette (2011).

“Wheeler got tremendously excited”: Ibid.

[>]
“a sort of patron of string theory . . . a conservationist . . . I set up a nature reserve”: Interview with M. Gell-Mann in
Science News,
September 15, 2009.

[>]
“M stands for Magic”: E. Witten in interview with Swedish public radio, June 6, 2008.

[>]
“I think all this superstring stuff is crazy . . . I don't like that they're”: R. Feynman in Davies and Brown (1988), p. 194.
“superstring physicists have not yet shown”: S. Glashow in Davies and Brown (1988).
“The long-standing crisis of string theory”: Friedan (2002).

[>]
“In viewing string theory”: DeWitt-Morette (2011).
“should be confined to the dustbins of history . . . violates the very spirit of relativity”: Ibid.
“the Wheeler-DeWitt equation is wrong”: Ibid.
“elegant . . . apart from some”: Ibid.
“We have made tremendous progress with string and M-theory”: M. Duff, private communication, 2011.
“M-theory is the
only
candidate”: Hawking and Mlodinow (2010), p. 181.

[>]
“quantum gravity . . . loop quantum gravity”: M. Duff, private communication, 2011.
“They can't even calculate what a graviton does”: P. Candelas, private communication, 2011.
“A lot of people are frustrated that this community”: L. Smolin in
Wired
, September 14, 2006.
annual string theory meeting: In 2008, at the annual jamboree for string theory—Strings 2008 held at CERN—Rovelli was finally invited to make the case for loop quantum gravity.

[>]
“It's a deal breaker”: Episode 2, Series 2, of
The Big Bang Theory,
Chuck Lorre Productions/CBS.

[>]
“approximate, emergent, classical concept”: Witten (1996a).
“geometry in the small”: Wheeler (1955).

 

13.
A SPECTACULAR EXTRAPOLATION

 

Not a lot has been written on modified theories of gravity that I can recommend. Barrow and Tipler (1988) and Barrow (2003) do an excellent job of discussing the large number problem that intrigued Dirac, which is also discussed in Farmelo (2010). Sakharov's scientific interests are cursorily discussed in Lourie (2002) and his own autobiography, Sakharov (1992). I recommend you take a peek at his collected works in Sakharov (1982) to see how concise he was. For the history of Milgrom and Bekenstein's theory, it is probably best to read one of Bekenstein's reviews; for example, Bekenstein (2007) is quite technical but will give you a flavor of what is going on. Peebles (2004) is a statesmanlike review of why looking beyond general relativity might be a good thing, and a more lay account can be found in Ferreira (2010).

 

[>]
“The beauty of the equations provided by nature”: P. Dirac, interviewed on Canadian radio, 1979.
“Experimentalists, especially those at NASA . . . as time went by”: Brans (2008).

[>]
“a man of universal interests”: A. Sakharov on Y. Zel'dovich in Sakharov (1988).
“I don't understand how Sakharov thinks”: Y. Zel'dovich on A. Sakharov,
http://www.joshuarubenstein.com/KGB/KGB.html
.

[>]
“People like Hawking are devoted to science”: Y. Zel'dovich on A. Sakharov in Sunyaev (2005).
“I felt compelled to speak out”: Sakharov (1992).

[>]
“The elegant logic of general relativity . . . a spectacular extrapolation”: Peebles (2000).

[>]
“At some point, I felt”: J. Bekenstein, private communication, 2011.
“Some looked at me as if I told them”: Ibid.

[>]
“a dirty word”: N. Turok, private communication, 2005.
“By no means have we ruled out MOND”: J. Peebles in Smeenk (2002).
“One has to take into account”: J. Bekenstein, private communication, 2011.
“I decided that it was time”: Ibid.
Bekenstein's theory: Bekenstein (2004).

 

14.
SOMETHING IS GOING TO HAPPEN

 

If you want to come to grips with the multiverse, you might want to try two of its most eloquent advocates, such as Susskind (2006) and Greene (2012), but temper them with the contrasting view of Ellis (2011b). If you want to follow the big experiments, you should check out websites such as the following:

http://www.skatelescope.org/

http://www.eventhorizontelescope.org/

http://www.ligo.caltech.edu/
These are full of interesting facts about what is actually going on at the coal face of observational research in general relativity.

 

[>]
textbooks: The two classic textbooks I describe are Misner, Thorne, and Wheeler (1973) and Weinberg (1972).

[>]
Event Horizon Telescope: A description of the Event Horizon Telescope can be found at
http://www.eventhorizontelescope.org/
.

[>]
“Black Hole Confirmed in Milky Way”:
http://news.bbc.co.uk/2/hi/science/nature/7774287.stm
.
“Evidence Points to Black Hole”:
New York Times,
September 6, 2001.
recent observation of a quasar: M. Capellari is asked about the biggest black hole discovered to date at
http://www.bbc.co.uk/news/science-environment-16034045
.

[>]
black holes at the LHC: An entertaining example of a response against black holes in the LHC can be found at
http://www.lhcdefense.org/press.php
.
“That is like asking what is north of the North Pole”: Jocelyn Bell Burnell, private communication, 2011.

[>]
“I do not believe the existence”: Ellis (2011b).
“The multiverse argument is a well-founded”: Ellis (2011a).
“I hope the current”: E. Witten in Battersby (2005).

BOOKS

 

Barrow, J.,
The Constants of Nature,
Vintage (2003).

Barrow, J., P. Davies, and C. Harper Jr.,
Science and Ultimate Reality: Quantum Theory, Cosmology and Complexity,
Cambridge University Press (2004).

Barrow, J., and F. Tipler,
The Anthropic Cosmological Principle,
Oxford University Press (1988).

Baum, R., and W. Sheehan,
In Search of the Planet Vulcan: The Ghost in Newton's Clockwork Universe,
Basic Books (1997).

Berendzen, R., R. Hart, and D. Seeley,
Man Discovers the Galaxies,
Science History Publications (1976).

Berger, A.,
The Big Bang and Georges Lemaître,
D. Reidel (1984).

Bernstein, J.,
Oppenheimer: Portrait of an Enigma,
Ivan R. Dee (2004).

Bernstein, J., and G. Feinberg,
Cosmological Constants: Papers in Modern Cosmology,
Columbia University Press (1986).

Bird, K., and M. Sherwin,
American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer,
Atlantic (2009).

Bodanis, D.,
E=mc
²
: A Biography of the World's Most Famous Equation,
Pan (2001).

———,
Electric Universe: How Electricity Switched On the Modern World,
Abacus (2006).

Bondi, H.,
Cosmology,
Cambridge University Press (1960).

Boslough, J.,
Stephen Hawking's Universe,
Avon (1989).

Burbidge, G., and M. Burbidge,
Quasi-Stellar Objects,
W. H. Freeman (1967).

Chandrasekhar, S.,
Eddington: The Most Distinguished Astrophysicist of His Time,
Cambridge University Press (1983).

Christensen, S., ed.,
Quantum Theory of Gravity: Essays in Honor of the 60th Birthday of Bryce S. DeWitt,
Adam Hilger (1984).

Close, F.,
The Infinity Puzzle,
Oxford University Press (2011).

Collins, H.,
Gravity's Shadow: The Search for Gravitational Waves,
University of Chicago Press (2004).

Cook, N.,
The Hunt for Zero Point,
Arrow (2001).

Cornwell, J.,
Hitler's Scientists: Science, War, and the Devil's Pact,
Penguin (2004).

Danielson, D.,
The Book of the Cosmos: Imagining the Universe From Heraclitus to Hawking,
Perseus (2000).

Davies, P., and J. Brown, eds.,
Superstrings,
Cambridge University Press (1988).

DeWitt, C., and B. DeWitt, eds.,
Relativity Groups and Topology,
Gordon and Breach Science Publishers (1964).

———, eds.,
Black Holes,
Gordon and Breach Science Publishers (1973).

DeWitt, C., and D. Rickles,
The Role of Gravitation in Physics: Report from the 1957 Chapel Hill Conference,
Edition Open Access (2011).

DeWitt-Morette, C.,
Gravitational Radiation and Gravitational Collapse,
D. Reidel (1974).

———,
The Pursuit of Quantum Gravity: Memoirs of Bryce DeWitt From 1946 to 2004,
Springer (2011).

Dickens, C.,
A Detective Police Party,
Read Books (2011).

Doxiadis, A., and C. Papadimitriou,
Logicomix: An Epic Search for Truth,
Bloomsbury (2009).