Beyond the God Particle (48 page)

15
. See “Higgs boson,”
http://en.wikipedia.org/wiki/Higgs_boson
(site last visited 3/8/2013).

16
. Leon M. Lederman and Dick Teresi,
The God Particle: If the Universe Is the Answer, What Is the Question?
(Mariner Books, 2006); see also
http://en.wikipedia.org/wiki/The_God_Particle:_If_the_Universe_Is_the_Answer,_What_Is_the_Question%3F
(site last visited 4/8/2013).

CHAPTER 2. A BRIEF HISTORY OF THE BIG QUESTIONS

1
. See “Democritus,”
http://en.wikipedia.org/wiki/Democritus
; see also “Classical element” and references therein,
http://en.wikipedia.org/wiki/Classical_element
(sites last visited 3/8/2013).

2
. Chemists write this as a chemical reaction: CH
₄
+ 2O
₂
→ CO
₂
+ 2H
₂
O, which translates into “one methane (CH
₄
) and two oxygen molecules (2O
₂
) react to make one carbon dioxide (CO
₂
) and two water molecules (2H
₂
O).” Note that the total number of oxygen
atoms
on the left side of the reaction is 2 × 2 = 4, since there are two O
₂
molecules, each containing two O atoms; the total afterward is 2 + 2 = 4, since 2 O atoms enter the CO
₂
molecule and two O atoms are present in the two water molecules.

3
. See our book
Quantum Physics for Poets
(Amherst, NY: Prometheus Books, 2010).

4
. See “Energy,”
http://en.wikipedia.org/wiki/Energy
, “Electron volt,”
http://en.wikipedia.org/wiki/Electronvolt
(sites last visited, 4/2/2013).

In discussing atoms and subatomic things, we use a very tiny quantity of energy, the
electron volt
, or
eV
. One electron volt is the energy that
a one-volt battery expends pushing a single electron
(the fundamental particle that orbits all atoms)
through an electric circuit
.

Most biological chemical reactions involve delicate, weaker chemical bonds, usually less than an electron volt per bond. Much of the entire stratum of biological processes is in the smaller energy range, around 0.1 eV. In contrast, the explosion of acetylene gas with oxygen liberates the energy of a triple carbon chemical bond—about 10 eV per acetylene molecule, and that is found to make a very loud bang—a shock wave in the surrounding air due to the release of chemical energy in the kinetic form. Indeed, high explosives such as TNT or fracking explosives can contain even higher energy bonds. Thus, around 10 eV, we enter the stratum of high-energy chemistry. By contrast, a proton and neutron can form a “deuteron,” which is the simplest compound nucleus, the nucleus of deuterium, or “heavy hydrogen,” and the energy released by this nuclear binding is about 2.23 MeV (million eV); this is a small nuclear binding energy. See
http://en.wikipedia.org/wiki/Deuterium
(site last visited 4/2/2013).

The conversion to larger energy units used in everyday engineering and macrophysics shows just how tiny this is. In the meter-kilogram-second system (mks), we use the energy unit “joule,” which is one watt of power for one second. A 60-watt light is consuming
60 joules of energy per second
. This is the electrical power (energy per time) consumed by the lightbulb. An automobile driving down the road at 50 mph typically has a kinetic energy (energy of motion) of 450,000 joules.

The conversion of joules to eV is 1 joule = 6.24150974 × 10
¹⁸
eV
. (That's approximately 6 followed by eighteen zeros.) The electron volt is a tiny unit of energy more appropriate for single atoms or particles, while joules are used for large macroscopic assemblages of atoms, such as mechanical engineering or electrical power applications.

Einstein's famous formula E = mc
²
implies that any particle at rest has an energy, E, that is equivalent to its inertial mass, m. We can therefore use energy units to quantify an elementary particle's mass. For example, the proton mass, which is 1.67262158 × 10
^-27
kilograms, can be restated in terms of electron volts, using the conversion 1 GeV/c
²
= 1.783 × 10
⁻²⁷
kg, so a proton mass is 0.938 GeV/c
²
(1 GeV = 1 billion eV; 1 MeV = one million eV).

We'll often drop the “/c
²
” and make a rough approximation, taking the proton and neutron masses to be approximately 1 GeV/c
²
, abbreviated to 1 GeV. The electron mass, likewise, is 0.511 MeV/c
²
, abbreviated to 0.5 MeV.

5
. Chemists write this as a chemical reaction: CH
₄
+ 2O
₂
→ CO
₂
+ 2H
₂
O + heat, which translates into “one methane (CH
₄
) and two oxygen molecules (2O
₂
) react to make one carbon dioxide (CO
₂
) and two water molecules (2H
₂
O).” Note that the total number of oxygen
atoms
on the left side of the reaction is 2 × 2 = 4, since there are two O
₂
molecules, each containing two O atoms; the total afterward is 2 + 2 = 4, since 2O atoms enter the CO
₂
molecule and two O atoms are present in the two water molecules.

6
. See “J. J. Thompson” and references therein,
http://en.wikipedia.org/wiki/J._J._Thomson
(site last visited 3/10/13).

7
. See “Ernest Rutherford,”
http://en.wikipedia.org/wiki/Ernest_Rutherford
(site last visited 3/10/13). “Good with his hands (unlike his mentor J.J. Thompson) and contemptuous of the head-in-the-clouds theoretical physicists, Rutherford was famous amongst his post-docs for acerbic quotes like the following: ‘Oh, that stuff (Einstein's relativity). We never bother with that in our work,’” quoted in David Wilson,
Rutherford. Simple Genius
(Hodder & Stoughton, 1983); Richard Reeves,
A Force of Nature: The Frontier Genius of Ernest Rutherford
(New York: W. W. Norton, 2008).

8
. Ibid.

9
. Ibid.

10
. Jan Faye,
Niels Bohr: His Heritage and Legacy
(Dordrecht: Kluwer Academic Publishers, 1991). See “Niels Bohr,”
http://en.wikipedia.org/wiki/Niels_Bohr
(site last visited 3/10/13).

11
. See “Cosmic ray,”
http://en.wikipedia.org/wiki/Cosmic_ray
(site last visited 4/2/2013).

12
. See “Nuclear physics,”
http://en.wikipedia.org/wiki/Nuclear_physics
, “Atomic nucleus,”
http://en.wikipedia.org/wiki/Atomic_nucleus
, “Protons,”
http://en.wikipedia.org/wiki/Proton
, “Neutrons,”
http://en.wikipedia.org/wiki/Neutron
. These are generically called “nucleons,”
http://en.wikipedia.org/wiki/Nucleons
. All atoms are characterized by the number of protons in their nucleus, or their “atomic number,”
http://en.wikipedia.org/wiki/Atomic_number
. The number of neutrons can vary, from zero for hydrogen, to well over 150 for heavy unstable atoms, etc. For a fixed number of protons, the number of neutrons can vary, leading to “isotopes,”
http://en.wikipedia.org/wiki/Isotopes
(all sites last visited 3/10/13).

13
. See “Hideki Yukawa,”
http://en.wikipedia.org/wiki/Hideki_Yukawa
, “Pion,”
http://en.wikipedia.org/wiki/Pion
, “Strong force,”
http://en.wikipedia.org/wiki/Strong_force
(all sites last visited 3/10/13).

The pion, like all strongly interacting particles, is actually a composite particle, made of a light quark (either “up” or “down”) with a light anti-quark (either “anti-up” or “anti-down”).

14
. See “Muon,”
http://en.wikipedia.org/wiki/Muon
(site last visited 3/10/13). Throughout this book we'll be placing emphasis on the muon because it is a truly point-like elementary particle (lepton) that has played a key role in unraveling the mystery of mass. It may also provide an avenue to the next generation of ultra-high-energy particle colliders, i.e., the Muon Collider. See
http://en.wikipedia.org/wiki/Muon_collider
(site last visited 3/10/13). Muons at rest live only about two millionths of a second (2 × 10
^-6
seconds). But because of a remarkable effect in relativity, as particles approach the speed of light, time slows down for them, and their lifetimes are extended; the muons are produced with energies that are hundreds of times their masses, and they can live hundreds of times longer, and this gets them down to the surface of the earth for detection.

15
. See “Manhattan Project,”
http://en.wikipedia.org/wiki/Manhatten_project
, and “Atomic bombings of Hiroshima and Nagasaki,”
http://en.wikipedia.org/wiki/Atomic_bombings_of_Hiroshima_and_Nagasaki
(sites last visited 3/10/13).

CHAPTER 3. WHO ORDERED THAT?

1
. See “Pion,”
http://en.wikipedia.org/wiki/Pion
(site last visited 3/10/13). The positively charged
π
⁺
is the “antiparticle” of the negatively charged
π
^–
. Antimatter was theoretically predicted by the young genius Paul Dirac in 1926, who merged quantum theory together with Einstein's theory of special relativity, as we discuss this in
chapter 9
. A few years after Dirac's prediction, the antielectron, dubbed the “positron,” was discovered in experiment. The theoretical prediction of antimatter is considered to be one of the greatest triumphs of twentieth-century physics. Each particle has a corresponding antiparticle species in nature. In some cases, like the photon and the neutral
π
⁰
, a particle can be its own antiparticle (we call such a particle “self-conjugate”; only electrically neutral particles can be self-conjugate).

2
. The
Wikipedia
article on the muon reads as though we wrote it:
http://en.wikipedia.org/wiki/Muon
(site last visited 3/13/13).

3
. The
Wikipedia
article on I. I. Rabi (pronounced “Robby”), a Nobel laureate, mentor of Leon Lederman, and a great and influential scientist, is well worth taking time to read:
http://en.wikipedia.org/wiki/Isidor_Isaac_Rabi
(site last visited 3/13/13). We quote the moving last paragraph from this article: “Rabi died at his home in Riverside Drive, Manhattan, from cancer, on 11 January 1988. In his last days, he was reminded of his greatest achievement in a poignant fashion when his physicians examined him using magnetic resonance imaging, a technology that had been developed from his ground-breaking research on magnetic resonance. ‘I saw myself in that machine,’ he remarked, ‘I never thought my work would come to this.’”

4
. See, e.g., the article on the Standard Model:
http://en.wikipedia.org/wiki/Standard_model
(site last visited 3/13/13). There are also many books and documentaries describing the history of particle physics and the Standard Model and beyond.

5
. See “Muon-catalyzed fusion,”
http://en.wikipedia.org/wiki/Muon_catalyzed_fusion
(site last visited 3/13/13).

6
. See the Fermilab site for the Muon Collider:
http://www.fnal.gov/pub/muon_collider/
. Searching online for “Muon Collider” pulls up stuff like:
http://www.dvice.com/archives/2012/07/muon-collider-c.php
(sites last visited 3/13/13).