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You're definitely correct, this article overhypes the mysteriousness. It's a shame, though, and a missed opportunity to go deeper, because it is a surprising fa

You're definitely correct, this article overhypes the mysteriousness. It's a shame, though, and a missed opportunity to go deeper, because it is a surprising fact that almost all of physics is most elegantly expressed in terms of least action principles, where it really does seem like the universe conspires to minimize some quantity. In classical physics, the Lagrangian formulation is merely useful for some calculations, and can be fairly viewed as a mathematical trick that is equivalent to using Newton's law directly; similarly in E+M it's a compact and often useful way to express Maxwell's equations, but not particularly fundamental. When you reach quantum field theory, though, it's all but impossible to do anything without a Lagrangian/action, and theories are almost always described in that form. String theories are the same. General relativity is not always presented that way, but gravitational dynamics are stunningly simple in that form: in a vacuum, nature abhors curvature. Principles of least X are fascinating and incredibly useful, and the ex-physicist in me believes that they describe the actual universe so concisely that they are truly fundamental in some sense. But you have to really dig in to get any sort of appreciation for that, and I agree that this article didn't go anywhere near deep enough.

zaptheimpaler 9y ago
Thats pretty interesting.. I wonder though - Does the universe seem to prefer minimizing some quantity, or do human brains gravitate towards theories that identify quantities that are minimized/maximized? Couldn't physical theories be expressed in many different ways, maybe with completely different fundamental concepts than mass/energy etc? Where the theories describing nature would not be so clean?
- Retra 9y ago
  That's the same thing here, though, since physics is a scientifically descriptive endeavor. Our conceptualization of the universe is limited by our perception of it, and thus the whole idea of "what the universe does" is fundamentally entangled in what we see it doing and how we can talk about it. So that the universe "optimizes" something must be true, given that only one past is observed. It has to have been optimizing for the past that we see. (It is perhaps more remarkable that we can make accurate predictions of the future, but this more or less seems to be a side-effect of optimization requiring some notion of continuity.) Our descriptions of nature are clean because they are based on observations of the past, which are the exact phenomena the universe appears to be optimized to produce. All other possible results are merely counterfactuals in our brains, and having those encoded in our theories would make them noisy and inaccurate. (And the best evidence for such counterfactuals being 'real' does exactly this by introducing quantum indeterminacy into the theory.)
QAPereo 9y ago
Hence the challenge of 6D (2,0) superconformal field theory.
Chris2048 9y ago
> it really does seem like the universe conspires to minimize some quantity. But there's only one min/max isn't there? Otherwise all values may be permitted, and we'd have entropy. The vast body of physics may concern behavior simple enough to be expressed, but much of reality behaves in complex ways?

zaptheimpaler 9y ago

Thats pretty interesting.. I wonder though - Does the universe seem to prefer minimizing some quantity, or do human brains gravitate towards theories that identify quantities that are minimized/maximized? Couldn't physical theories be expressed in many different ways, maybe with completely different fundamental concepts than mass/energy etc? Where the theories describing nature would not be so clean?

Retra 9y ago
That's the same thing here, though, since physics is a scientifically descriptive endeavor. Our conceptualization of the universe is limited by our perception of it, and thus the whole idea of "what the universe does" is fundamentally entangled in what we see it doing and how we can talk about it. So that the universe "optimizes" something must be true, given that only one past is observed. It has to have been optimizing for the past that we see. (It is perhaps more remarkable that we can make accurate predictions of the future, but this more or less seems to be a side-effect of optimization requiring some notion of continuity.) Our descriptions of nature are clean because they are based on observations of the past, which are the exact phenomena the universe appears to be optimized to produce. All other possible results are merely counterfactuals in our brains, and having those encoded in our theories would make them noisy and inaccurate. (And the best evidence for such counterfactuals being 'real' does exactly this by introducing quantum indeterminacy into the theory.)

QAPereo 9y ago

Hence the challenge of 6D (2,0) superconformal field theory.

Chris2048 9y ago

> it really does seem like the universe conspires to minimize some quantity. But there's only one min/max isn't there? Otherwise all values may be permitted, and we'd have entropy. The vast body of physics may concern behavior simple enough to be expressed, but much of reality behaves in complex ways?