Tuesday, August 01, 2023

A Mechanical Superstition

Just a hot take regarding this short video: A Bet Against Quantum Gravity (6.75 mins).

I don't have the credentials in the field to evaluate the merits of Jonathan Oppenheim's research program. But I have a natural philosopher's gut instinct. I like very much the fact that Oppenheim's theory allows information to be destroyed. As he says of the black hole information paradox, "It's only a paradox if you believe that physics somehow has to be deterministic."

Determinism, which is a feature of physical theories that physicists became used to from Newton, seems to imply that information cannot be destroyed or created, but is just shuffled around. This feature gives physicists the idea that they have the supposedly god-like power of predicting the future for all time, at least in theory. But in actuality, the evolution of things in nature is constantly producing real and unpredictable novelty. That was one of the lessons of quantum mechanics. Quantum indeterminism is so widely known as to be proverbial. And even if nowhere else, information is constantly being destroyed in the so-called collapse of the wave function, for which we have no physical law. What we have here is a failure of many, even great physicists to take to heart the lessons of quantum mechanics, leaving just a mechanical superstition.

The philosophical point that gives me pause is Oppenheim's insistence that the resulting novelty has to be stochastic, random; whereas in nature, novelty need not be random. But I think on the low level of the natural hierarchy with which his work deals, randomness is a good approximation and appropriate. And indeed, if we're talking about heat emerging from a slowly evaporating black hole, the motions of the particles have to be random.

There's more to be said about randomness and how it is often used in modern science as a placeholder for human ignorance more than an actual statement of the reality of things. I've taken up this theme elsewhere in this blog (regarding Darwinian evolution, for example) and I'm sure I'll return to it again, but it's beyond this hot take.

4 comments:

TheOFloinn said...

The problem goes back to Parmenides vs Heraclitus, no?

Lawrence Gage said...

I'm not sure what you mean. Please explain.

TheOFloinn said...

Parmenides envisioned the block universe of general relativity, in which all change was illusory. Heraclitus thought only change was real, anticipating the ever shifting mechanics of the quanta. Which is why no one has been able to reconcile the two.

Lawrence Gage said...

That's insightful! I agree the block universe is Parmenidean. I wouldn't quite say that quantum mechanics is Heraclitean. After all, there are still entities changing in QM, and laws that govern their change. But it's an illuminating comparison.

Certainly it's true that Aristotle's account of change combines Parmenides and Heraclitus, just as the physical theory we're looking for today would combine GR and QM.