Some Koans of Quantum Mechanics

After a two-week sesshin, and in deep meditation, a Zen disciple is tapped on the shoulder by a monk so the disciple can visit his Zen master about his assigned koan. He arises in the silent zendo, padding past others in lotus position, and enters a room for dokusan with his roshi. With a gassho to the Zen master, the disciple sits and waits for his teacher to speak. The roshi studies him silently. Then, rather than asking the student to show him Mu, the Roshi poses these to him, and they are all quantum puzzles:

~How can Schrödinger's cat be both half-alive and half-dead?

~Picture a massless particle. (That, however, is the case.)

~How can one change the past by delaying choice? (This, from John Wheeler's delayed choice experiment.)

~Show me velocity without location in space; show me location without velocity.(Heisenberg Uncertainty Principle.)

~Show me a tendency to exist. (Quantum Entanglement, or violation of the Locality Principle.)

~What are the other worlds in which wave functions collapse? (Hugh Everett's Parallel Universes.)

~ How can something exist as two wholly different things at the same time, a particle and a wave? (Wave-Particle Duality.)

The student sits, quietly frustrated. They gaze at one another. Then the disciple stands, gasshos, and returns to his zafu, or meditation cushion. He is perplexed, wondering if he now must learn theoretical physics in order to satisfy the Zen Master.

Of course, this is an absurd situation, as unlikely as a pianist playing Rachmaninoff on a sand dune deep in the Sahara.

In a sense, it is no more absurd than the problems posed by modern physics. Niels Bohr wrote "those who are not shocked when they first come across quantum theory cannot possibly have understood it." Of wave-function collapse and the Uncertainty Principle, Bohr said to Werner Heisenberg: "We may have to learn what the word understanding really means." Richard Feynman said, "I think I can safely say that nobody understands quantum mechanics."