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Reality doesn’t exist until it is measured, quantum experiment finds

anu.edu.au

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Re: Reality doesn’t exist until it is measured, quantum experiment finds

#61

Post by rbanffy »

marwatk wrote: post #25
davidrusu wrote: post #15

Clever optimization by our simulators, Big up

I've always wanted to read (or write?) a book about us determining we are in a simulation, but we find subtle flaws like this we're able to exploit in weird ways. Kind of like breaking out of a VM through register flaws or something. Anyone know of a story along those lines?

> Kind of like breaking out of a VM through register flaws or something

The difficulty is keeping track of the context while you attempt the exploit. You would have to be able to plant code outside the simulation without causing it to crash.

OTOH, from within, you'd only see a successful attempt to escalate privileges. Imagine being able to edit reality.

Re: Reality doesn’t exist until it is measured, quantum experiment finds

#62

Post by sosuke »

andyl wrote: post #10

Lazy instantiation.

You made me remember a comment I made some months ago about the speed of light being a performance optimization on a post asking if reality was a computer simulation.

https://news.ycombinator.com/item?id=8638150

Lazy loading makes perfect sense to me!

Re: Reality doesn’t exist until it is measured, quantum experiment finds

#64

Post by A_COMPUTER »

NeutronBoy wrote: post #42
icanhackit wrote: post #28

Earlier quoted context omitted.

Had to find a way to keep the framerate from dropping below Planck time levels.

Ah, but how do you know the simulation doesn't just slow down the simulated flow of time so it can keep up? Think of a bullet-time like concept. The universe can be simulated as fast as the underlying hardware can keep up.

Maybe the universe doesn't do it for the same reason games and movies don't do it, the people watching expect smooth playback.

Re: Reality doesn’t exist until it is measured, quantum experiment finds

#65

Post by pdonis »

photonic29 wrote: post #33
deciplex wrote: post #21

Earlier quoted context omitted.

Most physicists or, depending on who you talk to, nearly half of physicists, would appear to agree with you. I'm convinced that the Copenhagen interpretation remains popular because by making observation itself an integral part of the theory, you allow us to postulate that there is something special about human brains. But 'mysterious observation' is the luminiferous aether of quantum mechanics. photonic29: I would l…

Is that really the case though? An observation collapses a wave function. The Copenhagen interpretation suggests that the collapsed state arises from a probability distribution, but it does not address the "fundamental" origin of that distribution. MW attempts to address it by suggesting that the rest of the reality just went elsewhere, rather than disappearing or never having existed at all, but it still does not ex…

> An observation collapses a wave function.

Not if the MWI is true. Talking about wave function collapse presupposes that the Copenhagen interpretation is true. In the MWI, there is no collapse; it's unitary evolution all the time.

Re: Reality doesn’t exist until it is measured, quantum experiment finds

#68

Post by pdonis »

photonic29 wrote: post #30
hellbanner wrote: post #13

How can you measure what doesn't exist?

You can make an observation of a system whose state is undetermined. By interrogating the system for its state, a state becomes determined. Suppose, for example, that you have a flipped coin and sent it rotating in space, never hitting the floor. Is it heads or is it tails? Until it is looked at, the question doesn't really make sense. And for this case, we'll define "looking at it" to mean sticking out your hand and…

> You can make an observation of a system whose state is undetermined. By interrogating the system for its state, a state becomes determined.

For QM, this is not correct, although it's a common misstatement. The correct statement is this: you can make an observation of a system which is not in an eigenstate of the measurement operator you are using. After the measurement, the system is now in an eigenstate of the measurement operator--i.e., the act of measurement changes the state.

Note that this is only true on a collapse interpretation, like Copenhagen. On a no-collapse interpretation, like MWI, the "observation" is just an interaction that entangles the state of the measuring device with the state of the system being measured--it's all just unitary evolution.

> You could flip the coin, and put its state vector into the form of sqrt(2)/2 Heads + sqrt(2)/2 * Tails. This state isn't observable*

Yes, it is; but it isn't observable by a simple method like looking to see if the coin is heads or tails. But according to QM, every state is an eigenstate of some operator, so there will be some observation that will distinguish sqrt(2)/2 * Heads + sqrt(2)/2 * Tails from the state that is exactly orthogonal to it, which is sqrt(2)/2 * Heads - sqrt(2)/2 * Tails.

Re: Reality doesn’t exist until it is measured, quantum experiment finds

#69

Post by sova »

deckar01 wrote: post #39
westoncb wrote: post #5

This is of course extremely interesting and probably important for understanding our universe—but how is it helping anyone to say something like, "...with scientists performing a famous experiment and proving that reality does not exist until it is measured." The statement is like a distraction at a magic show, drawing the reader to the glittery 'reality' and 'exist,' which are totally undefined so the reader's imagi…

I think it is the most digestible title. "The Causality of Atomic Particles is Symmetric with Respect to Time" doesn't have quite the same ring to it.

holographic instantiation of composite routes

Re: Reality doesn’t exist until it is measured, quantum experiment finds

#70

Post by rosser »

marwatk wrote: post #25
davidrusu wrote: post #15

Clever optimization by our simulators, Big up

I've always wanted to read (or write?) a book about us determining we are in a simulation, but we find subtle flaws like this we're able to exploit in weird ways. Kind of like breaking out of a VM through register flaws or something. Anyone know of a story along those lines?

Check out Ken MacLeod's The Restoration Game.
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