Well, no information traveled. Rather it shows that the universe always keeps the pair of entangled objects balanced. If one is up, the other is down, etc.
So you measure one (it's random if it's up or down), and you know with 100% certainty that the other is the opposite.
If you stop there you get to what's called "Hidden variables", meaning the idea that at the moment it's created the other particle already is up or down, and you just don't know which it is (hidden information).
But the thing is you can measure up/down at any angle in the particle, and it's not possible for the particle to already have a pre-defined up/down for every possible angle.
So pick a random angle after separating the particles. Then let your teammate know which angle you are doing (this info is limited by the speed of light), and your measurements will always be exactly opposite each other.
Somehow when you measure the up or down, this measurement gets to the other particle, and no one knows how, because it gets there instantly. No info is transmitted (up or down is random), but the balance is always preserved.
Why it's like that isn't known. Obviously there are plenty of people who try to explain how and why it works - and all the theories work, with nothing to let you pick which one actually describes the real world.
All you can say right now is the math works, and the experiments match it. This is called "Shut up and calculate". i.e. some physicists say stop trying to understand it, since you can't, just make use of it.
> So pick a random angle after separating the particles
What I never understood is: is there any reason to believe this is even possible in theory, let alone in practice? Presumably everything started at a single point in the Big Bang, so wouldn't that necessarily imply all particles are causally connected (hence superdeterminism)? How can anyone make "random" choices when everything is linked? Under what accepted theory do scientists believe this experiment to be possible?
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.
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.
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.
> 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.
ars|2 years ago
So you measure one (it's random if it's up or down), and you know with 100% certainty that the other is the opposite.
If you stop there you get to what's called "Hidden variables", meaning the idea that at the moment it's created the other particle already is up or down, and you just don't know which it is (hidden information).
But the thing is you can measure up/down at any angle in the particle, and it's not possible for the particle to already have a pre-defined up/down for every possible angle.
So pick a random angle after separating the particles. Then let your teammate know which angle you are doing (this info is limited by the speed of light), and your measurements will always be exactly opposite each other.
Somehow when you measure the up or down, this measurement gets to the other particle, and no one knows how, because it gets there instantly. No info is transmitted (up or down is random), but the balance is always preserved.
Why it's like that isn't known. Obviously there are plenty of people who try to explain how and why it works - and all the theories work, with nothing to let you pick which one actually describes the real world.
All you can say right now is the math works, and the experiments match it. This is called "Shut up and calculate". i.e. some physicists say stop trying to understand it, since you can't, just make use of it.
dataflow|2 years ago
What I never understood is: is there any reason to believe this is even possible in theory, let alone in practice? Presumably everything started at a single point in the Big Bang, so wouldn't that necessarily imply all particles are causally connected (hence superdeterminism)? How can anyone make "random" choices when everything is linked? Under what accepted theory do scientists believe this experiment to be possible?
Laaas|2 years ago
Why?
jojobas|2 years ago
With hyperdeterminism it is. The direction chosen by the scientists is predefined every time.
loo|2 years ago
[deleted]
zmgsabst|2 years ago
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.
8bitsrule|2 years ago
'...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.
User23|2 years ago
[1] https://en.wikipedia.org/wiki/Pre-established_harmony
stouset|2 years ago
As far as I know, the first option (hidden variable theory) has been soundly disproven by experiment.
justinclift|2 years ago
> 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...
saagarjha|2 years ago