Farewell to Reality (50 page)

3
  Isaac Newton,
Mathematical Principles of Natural Philosophy,
first American edition, translated by Andrew Motte, published by Daniel Adee, New York, 1845, p.504.

4
  George Gamow,
My World Line: An Informal Autobiography,
Viking Press, New York, 1970, p.149. Quoted in Isaacson, pp. 355—6.

5
  Albert Einstein,
Zeitschrift für Physik,
16 (1923), p.228

6
  Hubble's law can be expressed as v = H
⁰
D, where v is the velocity of the galaxy, H
⁰
is Hubble's constant for a particular moment in time and D is the so-called ‘proper distance' of the galaxy measured from the earth, such that the velocity is then given simply as the rate of change of this distance. Although it is often referred to as a ‘constant', in truth the Hubble parameter H
⁰
varies with time depending on assumptions regarding the rate of expansion of the universe. Despite this, the age of the universe can be roughly estimated as 1/H
⁰
. A value of H
⁰
of 70 kilometres per second per megaparsec (2.3 × 10
^-18
per second) gives an age for the universe of 43 × 10
¹⁶
seconds, or 13.6 billion years.

7
  On submitting a paper describing their calculations to the journal
Physical Review,
Gamow added the name of fellow émigré physicist Hans Bethe to the list of authors. Bethe had not been involved in the work but Gamow, the author of the successful Mr Thompkins series of popular science books, had a reputation as a prankster. The possibilities afforded by a paper authored by Alpher, Bethe and Gamow had captured his imagination. Inevitably, it became known as the alpha-beta-gamma paper. The paper was published in 1948, on April Fool's Day. Gamow had originally marked it to indicate that Bethe was author
in absentia,
but the journal editor had removed this note. Bethe (who, as it turned out, was asked to review the manuscript) didn't mind. ‘I felt at the time that it was rather a nice joke, and that the paper had a chance to be correct, so that I did not mind my name being added to it.' (Quoted by Ralph Alpher and Robert Herman,
Physics Today,
August 1988, p.28.) However, Alpher was not overly impressed. The subject of the paper was his doctoral dissertation. Both Gamow and Bethe were established
physicists with international reputations. Anyone reading the paper would likely conclude that these more esteemed physicists had done all the work.

8
  Fred Hoyle,
The Nature of the Universe,
BBC Third Programme, 28 March 1949. A transcript of this broadcast was subsequently published in
The Listener
in April 1949. This quote is taken from Hoyle's original manuscript, selected pages of which are available to view online at
http://www.joh.cam.ac.uk/library/special_collections/hoyle/exhibition/radio/
.

9
  Ralph Alpher and Robert Herman,
Physics Today,
August 1988, p.26.

10
  Quoted by Overbye, p.130.

11
  Quoted by David Wilkinson, ‘Measuring the Cosmic Microwave Background Radiation', in P. James, E. Peebles, Lyman A. Page Jr and R. Bruce Partridge (eds.),
Finding the Big Bang,
Cambridge University Press, 2009, p.204.

12
  Quoted by Overbye, p.237.

13
  Guth, p.176.

14
  J. P. Ostriker and P. J. E. Peebles,
Astrophysical Journal,
186 (1973), p.467.

15
  Quoted by Panek, p.240.

Chapter 6: What's Wrong with this Picture?

1
  Albert Einstein, ‘Induction and Deduction in Physics',
Berliner Tageblatt,
25 December 1919.

2
  Why ‘modulus square'? The modulus of a number is its absolute value (its value irrespective of its sign — positive or negative). We use the modulus-square instead of the square of the amplitude because the amplitude itself may be a complex number (containing
i
, the square root of -1) but, almost by definition, the probability derived from it must be a positive real number — it refers to something measurable in the real world. The modulus-square of a complex number is the number multiplied by its
complex conjugate.
For example, if the amplitude is 0.5
i
, the square of this is 0.5
i
× 0.5
i
= -0.25 (since
i
×
i
= -1), which suggests a negative probability of -25%. However, the modulus-square is 0.5i × 0.5(-i) = +0.25 (since
i
×
i
= 1), suggesting a positive probability of 25%.

3
  Letter to Albert Einstein, 19 August 1935. Quoted in Fine, pp. 82—3.

4
  John Bell,
Physics World,
3 (1990), p.34.

5
  In Davies and Brown, p.52.

6
  Albert Einstein, ‘On the method of Theoretical Physics', Herbert Spencer Lecture, Oxford, 10 June 1933.

7
  Lederman, p.363.

8
  The Planck scale is a mass-energy scale with a magnitude around 10
¹⁹
GeV, where the quantum effects of gravity are presumed to be strong. It is characterized by measures of mass, length and time that are calculated from three fundamental constants of nature: the gravitational constant, G, Planck's constant
ħ
divided by 2π, written
h
(pronounced ‘h-bar') and the speed of light,
c.
The Planck mass is given by
and has a value around 1.2 x_ 10
¹⁹
GeV, or 1.2 × 10
²⁸
electron volts. The Planck length is given by
and
has a value around 1.6x10-
³⁵
metres. The Planck time is given by
(the Planck length divided by c), and has a value around 5 × 10
⁴⁴
seconds.

9
  John Irving,
A Prayer for Owen Meany,
Black Swan, 1990, pp. 468—9.

10
  Albert Einstein,
Preussische Akademie der Wissenschaften (Berlin) Sitzungsberichte,
1916, p.688. Quoted in Gennady E. Gorelik and Viktor Ya. Frenkel,
Matvei Petrovich Bronstein and Soviet Theoretical Physics in the Thirties,
Birkhauser, Verlag, Basel, 1994, p.86.

Chapter 7: Thy Fearful Symmetry

1
  Letter to Hans Reichenbach, 30 June 1920.

2
  For the incurably curious, U(l) is the unitary group of transformations of one complex variable.

3
  SU(2) and SU(3) are special unitary groups of transformations of two and three complex variables, respectively.

4
  Interview with Robert Crease and Charles Mann, 29 January 1985. Quoted in Crease and Mann, p.400.

5
  Stephen P. Martin, ‘A Supersymmetry Primer', version 6, arXiv: hepph/9709356, September 2011, p.5.

6
  Kane, pp. 53, 63.

7
  Martin, ‘A Supersymmetry Primer', op cit., p.5.

8
  Woit, pp. 173—4.

9
  Kane, p.67.

10
  Randall,
Warped Passages,
p.269.

Chapter 8: In the Cemetery of Disappointed Hopes

1
  Letter to Heinrich Zangger, 27 February 1938.

2
  Letter to Theodor Kaluza, 21 April 1919. Quoted in Pais,
Subtle is the Lord,
p.330.

3
  Letter to Paul Ehrenfest, 3 September 1926. Quoted in ibid., p.333.

4
  Leonard Susskind,
The Landscape: A Talk with Leonard Susskind,
www.edge.org
., April 2003.

5
  Interview with Sara Lippincott, 21 and 26 July 2000, Oral History Project, California Institute of Technology Archives, 2002, p.17.

6
  Interview with Sara Lippincott, 21 and 26 July, 2000, ibid., p.26.

7
  Woit, pp. 173—4.

8
  Interview with Shing-Tung Yau, 7 February 2007. Quoted in Yau and Nadis, pp. 131—2.

9
  Michael Duff, ‘A Layman's Guide to M-theory', arXiv: hep-th/9805177v3, 2 July 1998.

10
  Kragh,
Higher Speculations,
p.303.

11
  Quoted by Randall,
Warped Passages,
p.304.

12
  Veltman, p.308.

13
  Sheldon Glashow and Ben Bova,
Interactions: A Journey Through the Mind of a Particle Physicist,
Warner Books, New York, 1988, p.25.

14
 
Gordon Kane, ‘String Theory and the Real World',
Physics Today,
November 2010, p.40.

15
  Yau and Nadis, pp. 224—5.

16
  In P. C. W. Davies and Julian Brown, eds.,
Superstrings: A Theory of Everything,
Cambridge University Press, 1988, p.194.

17
  Randall,
Warped Passages,
jacket copy.

18
  Greene,
The Fabric of the Cosmos,
jacket copy.

19
  Hawking and Mlodinow, p.181.

20
  Quoted by John Matson,
Scientific American,
9 March 2011.

Chapter 9: Gardeners of the Cosmic Landscape

1
  Albert Einstein, ‘On the Generalised Theory of Gravitation',
Scientific American,
April 1950, p.182.

2
  ‘Have you noticed that Bohm believes (as de Broglie did, by the way, 25 years ago) that he is able to interpret the quantum theory in deterministic terms? That way seems too cheap to me.' Letter to Max Born, 1952. Quoted in John S. Bell,
Proceedings of the Symposium on Frontier Problems in High Energy Physics,
Pisa, June 1976, pp. 33—45. This paper is reproduced in Bell, pp. 81—92. The quote appears on p.91.

3
  H. D. Zeh,
Foundations of Physics,
1 (1970), pp. 69—76.

4
  These estimates are taken from Roland Omnès,
The Interpretation of Quantum Mechanics,
Princeton University Press, 1994. The original calculations were reported in E. Joos and H. D. Zeh,
Zeitschrift für Physik,
B59 (1985), pp. 223—43.

5
  John S. Bell, ‘Against Measurement',
Physics World,
3 (1990), p.33.

6
  Max Tegmark, ‘What is Reality?', BBC
Horizon,
17 January 2011.

7
  Peter Byrne, ‘Everett and Wheeler: The Untold Story', in Saunders et al., p.523.

8
  Quoted by Peter Byrne, in Saunders, et al., p.539.

9
  Max Tegmark, ‘The Interpretation of Quantum Mechanics: Many Worlds or Many Words?', arXiv: quant-ph/9709032 v1, 15 September 1997, p.1.

10
  Adrian Kent, ‘One World Versus Many: The Inadequacy of Everettian Accounts of Evolution, Probability and Scientific Confirmation', in Saunders, et al., p.309.

11
  Greene,
The Hidden Reality,
p.344.

12
  Andrei Linde, ‘The Self-reproducing Inflationary Universe',
Scientific American,
November 1994, pp. 51—2.

13
  Raphael Bousso and Leonard Susskind, ‘The Multiverse Interpretation of Quantum Mechanics', arXiv: hep-th/1105, 3796v1, 19 May 2011, p.2.