[acidburnNSA]

I had a fun time rigging my Geiger counter up to my computer for a little demo project of getting random numbers from radioactive decay. It's stupidly slow as is, but could be sped up. I should hook it up to my sound card multichannel analyzer and scintillator now that I have one and update this. Would be way faster with more pulses coming in from the lower-energy gammas and x-rays that the G-M tube can't see.

https://partofthething.com/thoughts/making-true-random-numbe...

[mikequinlan]

I haven't read the article yet, but I want to say that (so far) this is no actual proof that radioactive decay is random. There is evidence for it, and we assume it is, but it hasn't been proven.

[SideQuark]

There can be no proof, in the mathematical sense, of anything about the physical world, so radioactive decay being provably random in the most tested, accurate model of the world we have is as close to certainty as anything known about the physical world.

Semi-related is this year's Nobel Prize for experiments showing Bell's Theorem is physically true. This rules out hidden variable theories.

[agalunar]

I believe Bell's theorem specifically rules out local hidden variable theories, not all hidden variable theories.

[a1369209993]

Technically, even then it only rules out efficient local hidden variable theories. A theory where every particle carries a local hidden variable containing the entire state of the universe can (obviously?) emulate any other theory, quantum or otherwise (with a bit of finangling for things like quantum field wierdness).

[SideQuark]

Yes, you're correct. However, nonlocal hidden theories bring other issues that don't seem plausible. That's why the best current quantum field theories do make radiation a purely random event. None use nonlocal hidden variables.

[amelius]

Hmmm.

First you say that there can be no proof of anything about the physical world.

Then you tell about a Nobel prize for showing Bell's Theorem is physically true ...

[Timon3]

You left out the parts which answer your question. GP specifically wrote:

> There can be no proof, in the mathematical sense, of anything about the physical world[...]

followed by:

> Semi-related is this year's Nobel Prize for experiments showing Bell's Theorem is physically true.

The first quote refers to "mathematical proof", the second to "physical proof". They are different categories.

[amelius]

Ok, what is a physical proof then, apart from strong evidence?

[icegreentea2]

Mathematical proofs are in escapable conclusions of your choice of axioms (assumptions).

Negative physical proofs is evidence showing that a particular model (assumption) about the physical world does not hold. Negative physical proofs are relatively straightforward. Take your model, make a prediction, and then show the prediction is untrue in the physical world. This is more or less how the Bell Inequality test was supposed to be.

Positive physical proofs (for example, prove that radioactive decay is random), is in general not "actually possible". We can only show that physical reality is sufficienty compatible with your model.

[atoav]

Physical proof is not the same as mathematical proof. It is strong evidence for a mathematical model to be an adequate description of reality.

But that means we did not proof that the mathematical model is reality. There might be some weird edge case looming around the corner under which our model utterly fails to describe the physical world. Then we have to adjust the model or find a new one.

[acidburnNSA]

True. There's a whole debate about determinism in the universe, which includes radioactive decay. It's just one of those things that's considered roughly as random as it gets.

[cycomanic]

That's not really true. The Bells inequality experiments have proven (falsified) that there are no local hidden variables. The vast majority of scientists are not willing to throw away causality by accepting nonlocal hidden variables.

In other words the true randomness of quantum Events has been broadly accepted to reflect reality.

[dahart]

The article agrees, but of course it’s making a slightly different point and talking about what kinds of randomness are practically or even theoretically predictable today given what we know. Since nobody knows how to predict radioactive decay, it’s currently considered “truly” random, but its status could change in the future.

“Arguably then, from a truly omniscient perspective, nothing, not even the physical world, is truly random—it is in the nature of causality that everything that happens has a chain of prior events that caused it. But in practice, for most real-world randomness, obtaining such an omniscient perspective is infeasible to the point of being impossible.”