These and Those

Musings from Students of the Pardes Institute of Jewish Studies in Jerusalem

Quantum Mechanics and Baba Metzia

Posted on November 17, 2011 by S. Rotenberg

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I was studying Talmud and came across this connection to quantum mechanics.

In quantum mechanics, one of the many mysteries goes as follows: 

A particle x is shot at a device which measures if it is black or white. The scientist has no idea if the particle shot is black or white. In fact, the only thing the scientist knows is that ALL particles are black 50% of the time, and white 50% of the time*.

In the Talmud, in perek ב of tractate Baba Metzia, there is a concept of the owner of an object becoming in despair of his or her lost object. Raba argues that one is in despair at the moment the object is lost, even if he or she does not yet realize he lost it. Abaye argues that one is in despair as soon as he or she realizes the object is lost, and not a moment before.

This Talmudic question about emotional identity is being played out 2000 years later in the philosophy of quantum mechanics. If the particle does have a color before it is measured, it is by dint of the fact that it will be measured later. We can infer this because in further understanding of the particle, it is shown that this measurement determines that it have a definite color at all**.

This is what relates so heavily to the Talmud. To recap: if a particle has color before it is measured, it is believed to be only because its color will be measured in the future. Rabbi Raba defended this point 2000 years ago; the owner is in despair at the moment he looses his object, and it is because he is certain to be in despair later.

So, does the fact that the owner will come to know his object is lost make him in despair, even though currently he does not know the object is lost?  To take a lesson from quantum mechanics – possibly. In fact, I think that this understanding of this quantum mechanical mystery actually supports Rava in claiming that the owner is in despair even before he knows it.

*Although this is a simplification of the actual measurement that occurs, it is a perfectly parallel way to explain it. I did not come up with this – it is a common way used to describe the physics.

**If the particle is not measured, it will remain in a wave-state without a definitive color, but only possess the potential to be black 50% of the time and white 50% of the time.