Richard Carrier on Schrödinger´s Cat and the collapse of the wave function. Interesting. It´s from the commentary section to his essay about God and information, which I linked to previously (and now link to again).
>>>Sort of? There are a lot of assumptions in there. My answer could only apply to some specific examples of things some people say about that, not all. And you were a bit vague about exactly what you are talking about.
>>>But I think what you mean to ask is regarding the popular lore that, like Bumblebees Can’t Fly, quantum events require a mind “to observe them” to collapse them, therefore God must exist to collapse the wave function before humans did. That’s two confusions in one.
>>>First, humans can collapse a wave function into the past. People who think this popcorn nonsense don’t realize physics at that scale is time invariant, and that block theory is the standard physics of time now. So even if you needed a “mental” observer to collapse all wave functions, we could be that observer. It doesn’t matter that the function collapses in both time directions at once. Which means, yes, QM entails we could have caused the Big Bang in this obscure sense.
>>>But more relevant to your question, the idea that minds are needed at all is popcorn physics. In actual physics anything that disturbs a quantum state is an observer—a stick, a star, an atom. “Observer” is just figurative for “anything that produces an observation,” which need never be a mind.
>>>Consider the example of Schrödinger’s Cat. That was an example Schrödinger invented to make fun of people adopting this popcorn view, yet ironically—turning him in his grave—it now keeps getting used to sell the popcorn view he was making fun of, and even attributes it to him, when he was it’s most infamous opponent.
>>>In that experiment, a cat is in a box, with a detector that breaks a vial of cyanide when the atomic nucleus of a nearby unstable atom decays. The “joke” is that if you need an “observer” then the whole cat is somehow both alive and dead until you open the box. Schrödinger’s point was that this is stupid and therefore obviously false.
>>>He was right.
>>>First, the cat is an observer. It has a mind. It knows whether it’s dead or alive. So we don’t have to open the box for “its” wave function to collapse.
>>>But more importantly, per Schrödinger’s point: the detector of the atomic decay is also an observer. By sticking that object in the box, you have poked a stick into the quantum system that itself will collapse it. So the cat doesn’t even have to be in the box. There is no state of the box being simultaneously full of cyanide or not. Because the detector is collapsing the wave function all the time just by being there.
>>>In fact, the walls of the box, the air in the box. It’s all a bunch of sticks poking the radioisotope in the eye. They are all observers.
>>>To get an actual state of some volume being “both” cyanide and not cyanide, you would need to create something like a Bose-Einstein state of the transition phase of Nitrogen, Hydrogen, and Carbon into molecular cyanide, where it’s somewhere between free nitrogen and carbon and hydrogen and molecularly bound HCN (cyanide). That is so exceedingly difficult to do it may even be impossible. But there are simpler systems we can do it with. It’s just that you have to keep the BE glob perfectly balanced so nothing, absolutely nothing, shakes or comes into contact with it, because almost any interaction with it collapses the state.
>>>This is what it means to say that anything is an observer. “Observer” here does not mean “mind.” It means any physical interaction with the balanced state large enough to knock the state off balance and thus into some more definite state. It’s just that in experimental physics, it’s usually humans poking the sticks in, hence “observer” stuck as the rubric, even though it doesn’t mean what ordinary people mean by that word.
>>>But when no minds existed, plenty of sticks did. So quantum collapse routinely happened all over the place. Indeed, the Big Bang may itself be the first example of that happening, a balanced quantum state too unstable to stick around collapsed under its own weight and exploded. It was its own stick.
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