Some notes on Chapter 2: Einstein Called It “Spooky”: And I wish I had known
That evening with Einstein still haunts me (Bruce). And makes me regret (to put it mildly) that my courses in quantum mechanics left me unaware of the weirdness of the theory that Einstein want to talk about.
Something not included in our book: Einstein asked what we knew of David Bohm’s then-recent re-interpretation of quantum mechanics (see p. 163). We knew nothing, of course. We focused on perturbation theory and Feynman diagrams. Interpretations of quantum mechanics would not be on the final exam. When we went blank to his question, Einstein just remarked: “What David did is very interesting, but it is not what I told him to do.” I wonder…
When we discuss this chapter in class we bring up a couple of Einstein quotes. His most quoted remark expressing misgivings about quantum mechanics is, “God doesn’t play dice.” This comment is so often cited because it’s easy to understand. But randomness was not Einstein’s real objection to the theory. (A recent best-selling Einstein biography by a non-physicist has it wrong.)
Einstein’s serious objection to quantum mechanics was the measurement problem, the denial of a real world existing independently of its observation. It’s embodied in his, not-completely-in-jest statement: “I like to think the moon is there even if I am not looking at it.” (See p. 125.) That takes a bit of explaining. At this point, we briefly discuss this comment, and promise students that they will soon understand why Einstein said such a strange thing.
To add a bit to what we tell of our own backgrounds, not only has our physics research prior to our focus on the foundations of quantum mechanics been quite standard, the two of us have serious industry research and management backgrounds. Today, in addition to courses about the quantum enigma, we co-teach a course titled “The Physicist in Industry,” informally subtitled “How to get a good job and do well in it.”
We end Chapter 2, and we discuss this point a bit in class: a course like this would be unlikely years ago. (See p. 13 for a related comment.) When we wrote QE we thought we were at the crest of the wave of interest in the technical and popular interest in the weirdness of quantum mechanics. But interest keeps growing–both legitimate interest and in the unfortunately-best-selling pseudo-science.
Two popular articles we recommend to students are:
“Was Einstein Wrong?: The Weirdness of Quantum Mechanics Challenges Special Relativity,” D. Albert, Scientific American, March 2009 (Available at SciAm.com).
“The Reality Tests,” SEED, June 2008.
“Many Worlds” (Cover article), Nature, 5 July 2007.
And a recent and relevant more advanced book may be of interest:
On Physics and Philosophy, B. d’Espagnat, Princeton Univ. Press, 2009.