2024-08-16

  • Toward the end of Einstein’s life, Pauli visited Einstein to discuss QM.

  • Einstein reiterated his refusal to accept that a system can be defined only by specifying the experimental method of observing it.

  • Perhaps Einstein was referring to something like the measurement of the spin of a spin-1/2 system.
  • The measured spin is always entirely along the axis of the measurement-device, even though the experimenter may choose arbitrarily how to orient the device before the experiment is conducted.
  • Also, the measured spin is directed either up or down along the axis of the device, and it is often or even usually impossible to predict the measured direction.
  • So there seem to be at least two possible objection’s in Einstein’s mind.
    1. The objection to the fact that, regardless of how the spin might have been prepared before measurement, the measured spin is always entirely along the axis chosen arbitrarily by the experimenter.
    2. The objection to the fact that, if the incoming system, just before measurement, be not in an eigenstate of the device’s measurement-operator, then it is impossible with certainty to predict the result of the measurement.

  • It seems to me that the second of these is Einstein’s main objection, though it is not entirely independent of the first.

  • Ben's schedule this weekend:

  • 22-rifle, Aug 18 (Sun)

    • Hunt, 12:00, Range 3, Lane 4
    • Scope, 13:00, Range 6, Lane 17

  • air-rifle, Aug 18 (Sun)

    • 08:00, Relay 11, Firing Point 1

  • Booked room at SCP southern Colorado Springs for Saturday night.

  • St. Dominic nearby has Mass at 5pm Saturday.