Quantum mechanics and a moral dilemma
This past spring for my quantum mechanics course, I again used Schumacher and Westmoreland’s book Q-PSI which I had the good fortune to test over the past couple of years, prior to its publication. But I also used, as a supplement, Aharonov and Rohrlich’s Quantum Paradoxes. Interestingly enough, they couch Schrödinger’s cat ‘paradox’ in terms of morality. For readers not familiar with the paradox, here is the way Schrödinger envisioned it.
Place a cat in a box that also contains a vial of cyanide gas, a hammer, a Geiger counter, and a single radioactive atom. The hammer is connected to the Geiger counter in such a way that when the atom decays and the decay product is detected by the Geiger counter, the hammer swings down to break open the vial of cyanide gas killing the cat. According to Schrödinger, quantum mechanics tells us that, until we open the box and look inside, the cat is simultaneously both alive and dead – it is in a superposition of the two states. This is because the decay of the atom is probabilistic and we can have no way of knowing (until we open the box) whether the decay has happened or not (and thus whether or not the cat is dead).
There’s a subtlety here though. This paradox has been at the heart of discussions of the ‘measurement problem’ in quantum mechanics since it was proposed. That is, does the act of measurement cause the state to collapse to a definite outcome? In other words, does the opening of the box have an effect on the outcome? Schrödigner’s point in proposing this paradox was to show that the answer to the latter ought to be ‘no’ because it sounds absurd. And yet it is fairly well-accepted that, indeed, the act of measurement can have an effect (and it’s not hard to imagine scenarios – even classical ones – in which this is the case).
Aharonov and Rohrlich take this one step further. Let us assume that killing the cat is immoral, i.e. since we know that opening the box might kill the cat, we can’t unintentionally kill it. Now if the act of measurement does not have an effect on the state of the cat and the cat’s state is solely determined by the random process of the decaying atom, then, if it dies before we open it, whomever built the fiendish contraption is guilty of the cat’s murder. However, if the act of measurement does have an effect on the state of the cat, i.e. it truly exists in a superposition of states until the box is opened, and we find it dead upon opening the box, then we are guilty of the cat’s murder!
While fairly far-fetched, it nevertheless highlights the fact that science does not occur in a vacuum. There may be consequences – sometimes subtle – to what we do as scientists. It also highlights the importance of foundational research. I can envision a future in which a clearer understanding of the measurement problem could be morally important depending on the nature and state of technology. Let us hope funding agencies, politicians, and even corporations realize this.