Hacker News new | ask | show | jobs
by zmgsabst 1129 days ago
This shows that information about the measurement didn’t travel from one particle to the other.

Either:

- the information was always spread out (non-local)

- the two particles aren’t really separated, they just appear to be (non-Euclidean)

- the information was made up on the spot (non-real)

Scientists often don’t talk about the first two options; this article omits them, because it’s hard to think about (and violates an assumption scientists make — that you can study bits of reality in isolation).

Personally, I don’t think option #3 makes much sense — I think it was a calculation trick that has outlived its usefulness.

But that would mean admitting Einstein was right, which doesn’t let you write pithy article titles.

4 comments

But then Einstein said (if someone got the translation right):

'...for we physicists believe that the separation between past, present, and future is only an illusion, although a convincing one.'

Which is fascinating considering all the while he discussed 'synchronous events', talking about relativity, and how often time appears in his famous equations, eg E=mc^2 and K=8πG/c^4 . (c=meters/sec) A unitized 'spacetime' banishes time as a separable consideration.

It's as though we are trapped into a way of perceiving things that is wrong, but we haven't escaped that trap. OR... all of space-time is simply a giant, frozen, 4-D crystal in which the only thing moving - through the 3-D plane we call space - is our consciousness. If that's so, everything has already happened. OR... maybe that's mostly true, but not quite.

If that last thought intrigues you, you might enjoy reading Strange Life of Ivan Osokin by P.D. Ouspensky.

> If that last thought intrigues you, you might enjoy reading Strange Life of Ivan Osokin by P.D. Ouspensky.

Also Einstein's Dreams by Alan Lightman, a collection of short stories where each story is a universe where time functions differently than in our own.

It'll be a real trip if Leibniz's monadology ends up being the best fit for experimentally observed phenomena. Pre-established harmony[1] is one of those ideas that sounds crazy, but then you wonder, but then it sounds even crazier, but then you wonder even more. It's worth bearing in mind that the big L was one of the greatest minds of his generation, if not all time.

[1] https://en.wikipedia.org/wiki/Pre-established_harmony

> Scientists often don’t talk about the first two options; this article omits them, because it’s hard to think about (and violates an assumption scientists make — that you can study bits of reality in isolation).

As far as I know, the first option (hidden variable theory) has been soundly disproven by experiment.

Not when everything is held together by a non-local glue - which I assume is what your parent comment meant with the parenthesis.
IIRC based on my reading of this a while back: the non-local glue is some sort of mega-deterministic theory where everything about the universe is encoded in some function meaning non-local stuff happens because in the end everything is in the universe.

There is some state function that takes the universe… which was my understanding of the theory and ultimately very unsatisfying.

You only need the topology to carry quantum numbers, as I understand it. Anyons are experimentally confirmed to carry non-local quantum state (ie, a single quantum value shared across the constituent electrons).

Bohm worked before recent innovations, eg,

https://en.wikipedia.org/wiki/Anyon

https://en.wikipedia.org/wiki/Topological_quantum_computer

https://www.nature.com/articles/nphys1504#MOESM8

I was thinking about Bohm's theory which is the usual example of "hidden-variables" theory. Where the (not so) "hidden" part are the actual particles and their evolution is guided by the (non-local) wave function (defined in a 3N-dimensional configuration space).

https://plato.stanford.edu/entries/qm-bohm/

(stouset mentioned hidden variables but zmgsabst didn't - I'm not sure if that's what the latter was referring to.)

> - the two particles aren’t really separated, they just appear to be (non-Euclidean)

> this article omits them, because it’s hard to think about

"Hard to think about" seems strange? Wouldn't it just mean the particles are two instances of the same object?

Maybe I've just been programming for too many years...

They are.

But when you start unifying points like that (and making tiny punches in spacetime) you lose the ability to discuss it in terms of manifolds — which would mean that we lose most of our mathematics to do science.

We use these models not because they’re real — but because they’re the useful math we know how to calculate.

Well, wait a minute here. If they're the same particle, then how is it I measure spin up on one of them[1] and spin down on the other?

[1] Yeah, "on one of them" isn't the right wording, given the assumptions of the question...

I took a slightly liberal interpretation to their comment:

There’s two references to an underlying object, one of which presents the inverse of the other.

Think of it as there being a single strand of string - in a U shape. If I measure one end, I’ll measure the inverse twist direction on the other. Even if the twist direction is randomly chosen when I measure… because it’s a single string.

But only if I don’t have extra twists introduced along the U (ie, interactions with the environment).

In programmer terms, when you change the variables of one instance you're not necessarily causing the exact same change on the other instances?
Sure, but at that point, they aren't "the same object" (as justinclift said).
Heh, from a programming point of view it could be viewed more like a "master template" (the actual object), then multiple (transient?) instances created from that template.

No idea how that maps to this quantum stuff though. ;)

---

Hmmm. If you've used animation software before (?), then they commonly have a library of "assets" you can use in your animations. Those library assets would be like the "object", with several instances of it placed as needed in scenes, each slightly tweaked (size, colour, etc).