137: Jung, Pauli, and the Pursuit of a Scientific Obsession Part 16

"from the physicist's mode of thinking": Mach (1910), p. 37.

"to any G.o.d, authority or 'ism'": Pauli to von Franz, February 17, 1955: PLC6 [2019].

"will visual imagery be regained": Pauli to Bohr, December 12, 1924: PLC1 [74].

Bohr applauded Pauli's "wonderful results": Bohr to Pauli, November 25, 1925: PLC1 [109].

Pauli had done it "so quickly": Heisenberg (1960), p. 40; and Heisenberg to Pauli, November 3, 1925: PLC1 [103].

they had the theory right: Heisenberg and Jordan (1926).

"and by the lack of visualizability": Schrodinger (1926), p. 735.

"visualizability of his theory I consider c.r.a.p": Heisenberg to Pauli, June 8, 1926: PLC1 [136].

how the two sets of spectra arise: Heisenberg (1926). See Miller (1995), pp. 912 for details.

"who is calculating H+2 according to Schrodinger": Pauli to Wentzel, June 11, 1926: PLC1 [138].

wave functions that Burrau had deduced: Heisenberg to Pauli, November 23, 1926 [148]. See Burrau (1926/1927).

"state of almost complete despair": Heisenberg to Pauli, November 23, 1926: PLC1 [148].

in the end Born took the credit: Pauli included it as footnote to one of his papers on magnetism-Pauli (1927), p. 83.

"every time I reflect on it": Heisenberg to Pauli, November 4, 1926: PLC1 [145]; the letter Heisenberg referred to is Pauli to Heisenberg, October 19, 1926: PLC1 [143].

apply such words with great care: To give you a taste of the weirdness of quantum mechanics, the "numbers" it uses are of a nonstandard sort. So nonstandard that when Heisenberg published his original paper on the quantum mechanics he, himself, was confused. He found that when he multiplied the x-and y-coordinates for the position of a particle as xy, it was not the same as the value for the reverse order, yx-mathematicians say that in this case the property of commutativity does not apply: xy is not the same as yx. The numbers we deal with in our daily life possess the property of commutativity, which means that 3 2 = 2 3. Numbers like 2 and 3 commute.

But this is generally not so for quantum mechanics, where the mathematical symbols for position (Q) and momentum (P) do not commute. It boils down to the appearance of Planck's constant. If Planck's constant were zero, then Q and P would commute, that is, QP = PQ. Rather in quantum mechanics the relevant equation is: .

who had given him the key idea: Heisenberg to Pauli, February 23, 1927: PLC1 [154].

"It becomes day in the quantum theory": Heisenberg (1960), p. 40.

light and electrons behaved like particles: Heisenberg had concluded that collisions between electrons and light quanta were the root of uncertainties in any measurement of the electron's position and momentum. In this way he missed the critical point of examining how the accuracy of the measurement of the position of an electron is limited by how a microscope resolves the light entering its eyepiece.

To give more depth to the uncertainty principle, Bohr improved on Heisenberg's method of deducing the uncertainty relations by a.n.a.lyzing how the wavelength of the light bouncing off an electron is measured by a microscope.

In this way Bohr showed how important the wave-particle duality of light and electrons was in deducing the uncertainty principle.

context of waves and particles: Bohr went on to elucidate the critical role that Planck's constant played in measurements because if Planck's constant were zero, then there would be neither a wave-particle duality nor an uncertainty relation.

An electron's momentum (an aspect of its particle nature, p), and its wavelength (an aspect of its wave nature, ) are related by Planck's constant h as follows: p = h/. According to Heisenberg's uncertainty relation, the product of the error in the measurement of its position (x) and the error in the measurement of its momentum (p) is xp > h/2. Although Planck's constant h is very small-a tenth of a billionth of a trillionth of a trillionth-it is not zero. If it were zero then the electron's momentum and wavelength would be unrelated (there would be no more wave-particle duality) and the uncertainty relation would disappear as well.

This can be summarized schematically:

wave (h) particle error in position measurement (h) error in momentum measurement

In other words, Planck's constant determines the relationship between wave and particle and between the error in measurement of the position and momentum of an electron. So when if h (Planck's constant) is zero, we return to the world of our daily experiences in which there is wave-particle duality and there is no uncertainty relation.

This led Bohr to conclude that when any measurement is carried out in the world of atoms, the system undergoing measurement (in this case the electron) and the measurement system (the light which strikes it and caroms into a microscope) are inextricably linked, changing the properties of the system being measured in ways that cannot be exactly determined. In Newtonian science, on the other hand, we do not have to take into consideration the effects of light hitting a falling stone as we observe it.

"distinction between subject and object": Bohr (1961), p. 91.

he entirely agreed with Bohr's thesis: Bohr to Pauli, October 11, 1927: PLC1 [172]; Pauli to Bohr, October 17, 1927: PLC [173].

"wave and light quantum descriptions": Dirac (1927), p. 245.

"saddest chapter in modern physics": Heisenberg to Pauli, July 31, 1928: PLC1 [204].

"'I should have taken Bethe'": Interview with Weisskopf by Karl von Meyenn, July 10, 1963, in PLC2, p. xxi.

"applications of special relativity theory": Pauli (1940), p. 722.

Chapter 7 * Mephistopheles.

"And n.o.body understood anything": Interview with George Uhlenbeck by T. S. Kuhn, AHQP, March 30, 1962, p. 5.

"I like your publications better than I like you": Cline (1987), p. 138.

"only ONE G.o.d's whip (Thank G.o.d!!!)": Ehrenfest to Pauli, November 26, 1928: PLC1 [211].

at the appropriate time, use it: Interview with T. D. Lee by the author, Columbia University, April 23, 2008.

unified theory of gravitation and electromagnetism: Pauli to Einstein, December 19, 1929: PLC1 [239].

"So you were right, you rascal": Einstein to Pauli, January 22, 1932: PLC2 [288].

"not even accorded Bohr": Pauli to Sommerfeld, December 2, 1938: PLC2 [537a].

"may I formulate it this way": Weisskopf (1989), p. 160. Herr Geheimrat is usually translated as "Privy Chancellor." In this case Pauli meant it as "Honored Teacher."

"not sung to me in the cradle": Pauli to Pais, August 17, 1950: PLC4 [1147].

"without having Pauli read it first": The first quote is from Heisenberg to Pauli, November 21, 1925: PLC1 [107]; the second is from Hermann (1979), p. XLII.

"conscience of physics": Weisskopf (1989), p. 159.

"wicked stepmother": P/J [69P], October 23, 1956.

"which one had to find (and polish) oneself": Telegdi (1987), p. 433.

"demonic aura surrounding this queer man": Quoted from von Meyenn (2007), p. 248.

"with a rucksack on my back": Pauli to Weyl, November 9, 1955: PLC1, p. 443.

"Scherrer circus": Enz (2002), p. 198; and interview with Igal Talmi by the author, Weizmann Inst.i.tute, Rehovot, Israel, January 24, 2007.

"it is all right, but also wrong": Weisskopf (1989), p. 160.

"contradict me with detailed arguments": Pauli to Kronig, November 22, 1927: PLC1 [175].

"reinvigorate my interest in physics": Pauli to Bohr, January 16, 1929: PLC [214].

"I would like to meet you. Scherrer": Postcard written June 4, 1928: PLC1 [199]. In 1933 Jordan openly declared his membership in the National Socialist (n.a.z.i) party and became a Storm Trooper. This was no doubt why he never received a n.o.bel Prize. During the war Jordan worked for the n.a.z.i advanced-weapons program at Peenemunde.

Afterward Pauli stood up for his former pal "PQQP," and urged his reinstatement into academia, which occurred in 1953, paving the way for Jordan's return to the University of Hamburg. Soon afterward he was elected to the German parliament in the Adenauer days, as a member of the right-wing Christian Democratic Party. In this capacity he lobbied for arming the Bundeswehr with tactical nuclear weapons. Born, Heisenberg, and Pauli, among other scientists, strongly protested. As Pauli pungently put it, "Alas, good Jordan! He has served all regimes in utmost faithfulness" (Enz [2005], p. 47).

"he is already a.s.serting the opposite": Peierls (1985), pp. 4647.

"and psychoa.n.a.lysis as a vocation": Quoted from Pais (2006), pp. 1718.

"Not for the curious": Wentzel (1960), p. 51. The two papers are Heisenberg (1929, 1930). See Miller (1995), chapter 3, for details.

"rather introspective-i.e., Buddha-like": Pauli to Kronig, December 22, 1949: PLC3 [1067].

"Jew from the waist up": Interview with Igal Talmi by the author, Weizmann Inst.i.tute, Rehovot, Israel, January 24, 2007.

married only in a very "loose way": Pauli to Klein, March 10, 1930: PLC2 [243a].

"This gave him great satisfaction": Interview with Kathe Deppner by Jagdish Mehra, March 12, 1974, in Mehra and Rechenberg (1982), p. x.x.xvii.

"but with an average chemist": Interview with Franca, who was Pauli's second wife, by Charles Enz, March 21, 1971, in Enz (2002), p. 211.

"vehemently plagued by jealousy": Weyl to Hecke, May 28, 1930: PLC5, p. xxi.

Kathe married her chemist, Paul Goldfinger: After the war, from time to time, Kathe used to show up unexpectedly at Pauli's home in the small town of Zollikon, just outside Zurich. Franca did not at all appreciate this and refused to let her in, so Pauli went on long walks with her. Interview with Karl von Meyenn by the author, November 14, 2006.

plus the discharged electron: At the time physicists were debating about whether there were electrons as well as protons inside the nuclei of atoms. But this model of the nucleus led to certain properties that clashed with those measured in the laboratory. The discovery of the neutron, in 1932, clarified the situation. The neutron has about the same ma.s.s as the proton and the same spin, but it has no electric charge. In beta-decay the neutron transforms itself into an electron, a proton, and a neutrino, and the electron is immediately expelled from the nucleus.

"We must still be prepared for new surprises": Bohr (1930), p. 371.

"that something was missing": Interview with Igal Talmi by the author, Weizmann Inst.i.tute, Rehovot, Israel, January 24, 2007.

"which further behaved foolishly": Pauli to Delbruck, October 6, 1958: PLC8 [3075].

a ball at the splended Baur au Lac: Pauli to Meitner et al., December 4, 1930: PLC2 [259].

"But under 'dryness' I don't suffer at all": Pauli to Peierls, July 1, 1931: PLC2 [279].

"until my bones are whole again-very tedious": Pauli to Peierls, July 1, 1931: PLC2 [280].

"like a traffic cop signalling": Tippys to Goudsmit, August 19, 1931: PCL2, p. 84.

inverse Pauli effect: Quoted from PCL2, p. 84.

raised his hand in a "Heil Hitler" salute: Quoted from PLC2, p. 84.

"second-order acquaintances": Pauli to Wentzel, September 7, 1931: PLC3 [283a].

"very simple and very neat here": Pauli to Wentzel, September 7, 1931: PLC3 [283a].

"Your old Pauli": Pauli to Wentzel, September 7, 1931: PLC3 [283a].

"two problematic temperaments": Pauli to Weisskopf, December 30, 1940: PLC3 [615].

"increase her publicity with your help": Pauli to Delbruck, October 6, 1958: PLC8 [3075].

infuriating grin and a long tail: Gamow (1985), pp. 165214.

delighted to be cast in this role: Schucking (2001), p. 46. For more on this spoof, see Segre (2008).

Chapter 8 * The Dark Hunting Ground of the Mind.

three for extremely important: Pauli's personal library is housed in La Salle Pauli in CERN.