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Comment by dxhdr | Hacker News Reader

At the risk of being "that guy," a few thoughts popped into my head after reading this article. I couldn't help but reflect on the possibility of us just completely misunderstanding how the universe works. It wouldn't be the first time in history. What if:

Our concept of time and matter is wrong, or our idea of quantum physics is interesting and useful, but ultimately wrong.

Perhaps I'm just a simpleton but part of me really wants to believe we're missing something fundamental that would make all of this so much easier to accept and understand.

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At a mathematical level, it's pretty elegant how quantum mechanics works. At the level of the article, not so much.

Once you get the math (and it really kind of clicks all at once), it's not too hard. The problem is that the math has a lot of historical baggage and the ways of translating equations into prose are not the most effective I think.

The whole "uncertainty" thing bothers me. I think there's better ways of expressing this concept to the public.

I am, however, bothered by the fact that QM is not deterministic. Most experiments have ruled out loopholes for a deterministic universe, but it still just weirds me out that randomness is inherent to the measurement of observables.

Do you have any sources for experiments ruling out our universe being deterministic? I'm not questioning you. I honestly have always been intrigued with the idea. Thanks.

The standard answer is the Bell inequalities, but if you only care about deterministic vs. nondeterministic then Conway's "free will theorem" is a bit simpler.

(The result is that either which quantities we choose to measure must be deterministic, or physics must be nonlocal (i.e. what we do in one place can change what we measure in another place even if the two experiments happen simultaneously), or the results of our measurements must be nondeterministic)

Nothing says we live in a local universe.

There's no proof, sure. But nonlocality is very counterintuitive, arguably more so than nondeterminism (and there are no familiar classical/macroscopic phenomena that exhibit nonlocality, whereas many familiar things at least appear nondeterministic in practice).

There are certainly interpretations of QM that are deterministic. See many worlds, for example.

Personally, I've never found that a comforting alternative.

It just because people tell about it as if all the possible divergent trajectories through phase space happen not just ours. What they actually mean is that the possibilities are vast and we have no idea why reality chose exactly this path because it's not in any way priviledged.

It's like a ball a top of the totally symmetric hill. If you consider phase space it contains ball rolling down in all the possible directions but noone claims that ball rolls in all of them in alternate universes. It rolls down in exactly one way though we might never have any idea why it chose this one.

That sounds exactly like non-determinism, which is what we were trying to avoid.

You're only the ten millionth person to voice that desire. Sadly, the universe is not obligated to be intuitive. At this point we probably have to accept that the parts of the universe that we didn't evolve to understand are free to be as utterly weird as they want to be.

Sure, but what are the odds the universe fundamentally defies intuitive logic versus the odds our small brains currently can't see the full picture but in the meantime have invented insane (but cool) mathematical machinations? I guess it's unknowable.

But what do you think physicists do all day? Exactly what you just described. Unfortunately we pretty much have the answer, and it's kind of a resounding NO. Look up "local hidden variable theory".

Lets not put pollute this discussion with that piece of wishful thinking :)

please read Anathem http://www.amazon.com/Anathem-Neal-Stephenson/dp/0061694940/... (if you've not already) I think you will enjoy it :)

[edit: removed wikipedia link... too many spoilers :(]

In that case it turns out that some extremely simple intuitive rules can generate some very unintuitive results. Those results may perhaps best be approximated by extremely complicated mathematics. c.f. chaos theory and turing equivalent 1-d cellular automata.

I can't see any basis on which to assign the probabilities you ask for. A better question might be: on what basis do you believe that the universe should be intuitive? Why should it be so?

You may not be so "out there" at all. There were two books that came out a few years ago, both basically lambasting the state of physics - especially string theory. One was titled Not Even Wrong[1] and the other was titled The Trouble With Physics[2]. As best as I can tell, of the two (and I'm afraid I can't remember which it was now) made the case that we might be completely wrong about the nature of time. The idea was that the reason we have had to resort to such (seemingly) byzantine theories as string theory, without seeming to make much progress on deciding which string theory is correct (or if it's correct at all) is tied up in this misunderstanding of time. IOW, before we make any really fundamental breakthroughs in physics, we will have to re-conceptualize time itself.

Now that's a pretty bold claim, and I have no idea if it is correct or not. But it's a position held by at least one fairly well known and reputable physicist.

[1]: http://www.amazon.com/gp/product/0465092756

[2]: http://www.amazon.com/The-Trouble-With-Physics-Science/dp/06...

Anyone who claims they understand Quantum Physics, doesn't understand Quantum Physics – Feynman

If you are not completely confused by quantum mechanics, you do not understand it - Bohr

I think the fundamental problem is the idea that there is more than one thing. As soon as you see there is only one thing, it's no surprise that everything is related. http://philosophy.stackexchange.com/q/4751/2992

But in that case, wouldn't physics be non-local after all? Do you believe that it is non-local?

It is sobering to realize there are some things I'll never understand. But it's OK. Ignorance let's us have more fun speculating. I was wondering, are two entangled particles actually the same particle, where one or both "took a time machine" to get to the other place?

This train of thought has to have something to it. There is obviously something that is "the same". Perhaps it is something more fundamental than the photons that "generates" the photons. Or, if it doesn't "generate" them, it determines the state of them at least.

In "Many Worlds", the "something" would be the particular universe that "this instance" of ourselves ended up in.

We're most certainly missing a lot of things. But quantum mechanics is in no way wrong. It may not be complete, but not wrong.

Ontologically, there is not reason for us not to discover other things about nature that are (more) fundamental.

You sound far too certain for my liking. But IANAP.

It's possible (in fact almost certain) that we don't know anything, but it's unlikely that we're missing something that would make it easier to accept: any true theory of physics would have to explain nonintuitive experimental outcomes like the bell inequalities or the "free will theorem".

FWIW, if one bites the bullet and assumes the equations mean what they appear to mean then it's a lot simpler than you might think. My first thought on looking at the diagram in the article was "well duh".

Don't worry, in 500 years, after everything that is now studied is well understood, there will be one or more underlying principles discovered which will simplify it all.

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