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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

#171

Post by david927 »

Ygg2 wrote: post #141

Um, this doesn't prove reality doesn't exist until it is measured. It just proves that measuring and "decision" which state to appear in happens simultaneously. It could mean that time on quantum scale doesn't differentiate past/future.

Sure it does because, while certainly quantum scale doesn't carry the same sense of time, we do.

Everything we see, what we call reality, is made up of the Lego blocks of electrons, protons and neutrons, and yet even at that level it makes no sense to talk in concrete terms about, say, an electron's spin. We would expect that the spin exists and we find out what it is when we measure it, but it's not that. It's that talking about its spin is meaningless until you measure it. What you can reason about the Lego blocks of everything we see, smell, touch and taste, what gave birth to us and what will kill us, is indescribable until it's asked to be described. Whether that's because it's locked-in to time or not is irrelevant because it means the same thing: reality is not there until it's there.

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

#172

Post by ilitirit »

hackinthebochs wrote: post #71

Let us not forget about Pilot-Wave theory, where it has both particle and wave-like properties simultaneously. In fact, I don't quite get why people are so enamored by these fanciful interpretations when Pilot-Wave is so much more down-to-earth.

I'm not really qualified to talk on a technical level about the matter, but besides the distaste some people have for Aether Theories, there are other reasons some scientists don't like PWT, especially as it's demonstrated by the behaviour of oil droplets.

The physical, conceptual differences between any quantities describing droplets on one side and the wave function on the other side are clear. The former are observable – you may actually measure what the shape of the droplet looks like; you can't measure the wave function by any apparatus, at least not in a single repetition of the experiment. The former has an objective interpretation; the latter has a probabilistic interpretation, and so on. The wave function just encodes all the probability distributions for actual observables – but the wave function isn't and can't be one of them.

http://motls.blogspot.com/2014/07/droplets-and-pilot-waves-v...

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

#173

Post by Strilanc »

yummyfajitas wrote: post #162
Strilanc wrote: post #161

The linked article is titled "Experiment confirms quantum theory weirdness". Please don't exaggerate the title. These experiments do not show that "reality doesn't exist until it's measured". First, "realism" [1] is not the same thing as "reality". "Realism" basically means "physical quantities have a definite value". "Reality" is that thing that determines your experimental outcomes. Don't mix them up. Second, inter…

I don't think the title is a misrepresentation of the article , just the physics: From the article: "It proves that measurement is everything. At the quantum level, reality does not exist if you are not looking at it..." The article does appear to be (incorrectly) arguing that this experiment proves one interpretation of QM correct. It's definitely incorrect - some years back myself and others used non-experimentalis…

Yes, the article does quote the physicist saying that. Physicists do say things like that, without adding caveats like "assuming the Copenhagen interpretation, which is the plurality opinion and my de-facto working theory day to day".

But the article didn't include it in the title, and I think that was the right choice. And HN usually tries to keep the original title.

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

#174

Post by rbanffy »

rbanffy wrote: post #59
marwatk wrote: post #25

Earlier quoted context omitted.

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?

I think Charlie Stross did a particularly interesting one that happened within a simulation where the characters ultimately discover the enemy they were fighting already won and their simulation ran under a larger simulation. Can't remember the name...

Actually, it's Cory Doctorow and Benjamin Rosembaum's "True Names".

My confusion is a compliment to all three authors.

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

#175

Post by Strilanc »

misnome wrote: post #170
Strilanc wrote: post #166

Earlier quoted context omitted.

That would quite possibly be the worst optimization ever. "Yeah, I could have tracked and updated n values pretty cheaply, but instead I decided to exponentiate an exponentially huge matrix and use that to update a vector containing 2^n complex numbers associated with the possible assignments of the original n bits. Also, you should use bogosort. It's the best."

That is assuming that whatever reality our simulation was running in followed the same rules.

Of course. I used that assumption because it was also implicit in the original claim. If we don't have any idea what the top-level rules are, then claiming quantum mechanics is an optimization artifact falls a bit flat.

If the top-level rules are classical-ish, then quantum mechanics is expensive instead of cheap. If the top-level rules are quantum-ish, then that begs the question of why we thought quantum implied simulated. If the top-level rules are totally different... then there's not really much to be concluded.

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

#176

Post by ilitirit »

hasenj wrote: post #84

I'm not familiar with this particular experiment, but all my pondering on the subject - as a layman - leads me to a simple conclusion. The properties these experiments are measuring are simply bogus. They are not well defined. The answer that comes out is not some intrinsic property of the "particle", but the result of the environment in which the particle interacted with the "measurement" system, so to speak. The pa…

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

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

#177

Post by joshuahedlund »

antimagic wrote: post #154
zw123456 wrote: post #86

And perhaps someday we'll get to meet the great programmer in the sky the developed the simulation we are living in and we will ask him why he designed it that way and he will say something like "oh I just wanted to optimize the code so I simply excluded reality subroutines when there were no beings looking. I just never thought you guys would notice. As soon as I saw that you guys noticed the flaw, I was going to lo…

I always find it fascinating at just how much of our fundamental physics ends up being constraints on information movement. The laws of thermodynamics are about entropy, general relativity puts constraints on the movement of information (for example, Spooky Action as a Distance(tm) is faster than light, but you can't transmit information with it), the Uncertainty Principle puts limits on how much information you can…

I'm fascinated by such things also. I often can't help thinking of God as a programmer, though I don't know how much of that is confirmation bias of my priors as a theist and a programmer. But I've always thought the periodic table and DNA both felt a lot like code...

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

#178

Post by Ygg2 »

david927 wrote: post #171
Ygg2 wrote: post #141

Um, this doesn't prove reality doesn't exist until it is measured. It just proves that measuring and "decision" which state to appear in happens simultaneously. It could mean that time on quantum scale doesn't differentiate past/future.

Sure it does because, while certainly quantum scale doesn't carry the same sense of time, we do. Everything we see, what we call reality, is made up of the Lego blocks of electrons, protons and neutrons, and yet even at that level it makes no sense to talk in concrete terms about, say, an electron's spin. We would expect that the spin exists and we find out what it is when we measure it, but it's not that. It's that…

You can only conclude that "Physical reality doesn't exist until observed", if you imply nothing can move faster than light.

Also hidden variable theory aren't yet categorically disproven. A fractal theory could explain why we keep getting different results when measuring reality in different ways.

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

#179

Post by orbifold »

joshuahedlund wrote: post #177
antimagic wrote: post #154

Earlier quoted context omitted.

I always find it fascinating at just how much of our fundamental physics ends up being constraints on information movement. The laws of thermodynamics are about entropy, general relativity puts constraints on the movement of information (for example, Spooky Action as a Distance(tm) is faster than light, but you can't transmit information with it), the Uncertainty Principle puts limits on how much information you can…

I'm fascinated by such things also. I often can't help thinking of God as a programmer, though I don't know how much of that is confirmation bias of my priors as a theist and a programmer. But I've always thought the periodic table and DNA both felt a lot like code...

The masons thought about God as the great builder, I believe generally we make gods in our own image.

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

#180

Post by stefantalpalaru »

dghf wrote: post #137
mjfl wrote: post #53

Earlier quoted context omitted.

The philosophical interpretation of Quantum Mechanics is a very hard, unsolved problem. There are many reasons why quantum mechanics is theoretically good and philosophically terrible, and not just in a subtle, esoteric way. The reason is that in Quantum Mechanics there are 2 main types of entities: particles, "things" that evolve according to the Schrodinger equation, and "observers". Observers are what deliver to u…

> Observers are what deliver to us the results of randomly sampling from the probability distribution defined by the squared amplitude of the wave function by "collapsing" it, according to the Copenhagen interpretation. However, there is no particle that acts as an observer, they all just follow the Schrodinger equation, but nothing that exists isn't a particle. This is why proponents of the Many-Worlds Interpretatio…

> Occam's razor favours it

Occam's razor is not a scientific principle, it's just a rule of thumb. I have yet to see a proof that given a number of equal strength explanations for a phenomenon, the simplest one is always true.

One other thing that's often forgotten is that in Occam's opinion the simplest explanation for everything was God.

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