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Comment by resource0x | Hacker News Reader

If I read it correctly, the implication is that the present affects the past. If photon 1 died a billion years ago (without being 'measured' by sentient observer) - e.g. by just hitting a wall, its polarization remained undefined until we measured photon 4 today. This is not very intuitive. Polarization of photon 1 could, in principle, cause a galactic catastrophe, and by measuring photon 4 today you either trigger this catastrophe (a billion years ago!) or your don't - depending on the results of your measurement.

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Sentient observers have got nothing to do with that – interaction with any macroscopic system will destroy the entanglement.

If that macroscopic system (a galaxy that might have a catastrophe triggered or not) is causally connected to us, then it's destiny doesn't depend on the measurement, because it's state have already been "decohered" with us. (That is; the information about the other photon has already indirectly entangled with us.) If it isn't, then it's still entangled, and it indeed does depend on the measurement – it's a Schrödinger's galaxy.

> interaction with any macroscopic system will destroy the entanglement.

How do you know it? I'm not aware of any proof of this statement.

Are you aware of some proof that it is specific to sentient entities? If not, Occams razor implies we assume it is any macroscopic entity.

Can you present a proof that hasn’t been created by a sentient entity?

Edit: of course you can, but only in the formal systems sense, which is relativel trivial.

What we think of as “proof” in physics is a combination of “this belief creates predictable experiences” and “this abstraction of belief is logically consistent.”

The first part is subjective - our beliefs about physics create predictable experiences for us, but we have no idea how large the entire domain of possible experiences is.

The second part is a tar pit full of bones, haunted by undefinability theorems.

https://en.m.wikipedia.org/wiki/Tarski%27s_undefinability_th...

So any suggestion that physics efficiently reveals the secret mechanisms of the universe is a conceit. Physics reveals what we’re able to deduce about the universe given the biases built into our experience of sentience.

When weird things fall out of quantum theory, this makes it hard to know if the weirdness is truly out there, or if it’s an artifact of our limited sentience.

When photon hit rock, rock measure photon. Quantum of energy. Wave function collapse. Human brain not needed. Earth also not flat.

There isn't any proof – of course – because any non-sentient macroscopic system couldn't testify this to us. Otherwise we would call it sentient.

However, I have the premise here that sentient systems are fundamentally similar to non-sentient systems. That is, there isn't any "special sauce" – such as soul or midi-chlorians – that causes sentient systems behave differently on micro-physical level. Instead, sentience is an emergent property, that shouldn't have effect in "low-level" details of how the universe works. This comes basically back to Occam's razor, like the other comment said.

> That is, there isn't any "special sauce"

Well, this is a big claim. In fact, no one knows. My premise is that there is special sauce, but we know nothing about it at the moment. In any case, it's just my word against your word :)

To elaborate: I don't claim to know if there is or isn't anything like that and I'm not interested of arguing about that here.

What I am saying is that if a phenomenon is explainable with less "special casing", we should buy into that explanation rather than a more complicated one. Quantum physics is explainable without the concept of sentience; it's just ABC's of philosophy of science that we shouldn't try to include anything more into our theory than is needed.

I don't feel qualified to judge whether it's explainable or not. But 2 guys familiar with the matter believe it is not :) Not that I appeal to authority, it's just to demonstrate that the jury is still out. https://en.wikipedia.org/wiki/Von_Neumann%E2%80%93Wigner_int...

We generally cannot prove things about physics in a mathematical sense, but assuming that our understanding of quantum mechanics is correct, every interaction of an entangled particle causes its entanglement to "spread" to the interacting object. That's just a property of the math involved in describing quantum systems.

This means that once you have macroscopic interaction, the entanglement basically starts to spread at the speed of light, i.e. it'll quickly spread to humans.

Once you are entangled with something, you can no longer observe the effects of that entanglement (you are no longer an external observer), and it looks as if the entanglement was destroyed.

You didn't read it correctly. They measure photon 1 before photon 3 or 4 even exist.

They measured photon 1 because they wanted to prove correlation (it would be impossible to do without measuring it). If you believe they proved it, it works both ways. Hadn't they measured photon 1, our measurement of photon 4 would determine polarization of photon 1 a billion years ago. Entanglement works both ways, according to the theory.

Not just in theory! Isn't this what Alain Aspect tested?

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