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The quantum eraser experiment tells us that a photon shot at two slits is a wave, unless you measure which slit is taken and you do not destroy the measurement result.

I've found this very similar to the notion of 'lazy evaluation' in computer science. Only evaluate when it is certain the result is required.

Konrad Zuse's theory for 'rechnender raum' or a computing universe was always just a theory.

But could the behaviour of photons not be described as the 'lazy evaluation' of a computed universe. If the 'which slit information' is not required, the universe never bothers to compute this information. Somehow, the computed universe is optimized?

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I'm a .NET developer thinking about the same idea, there is lazy loading in .NET, only provide data when system really need this piece of information, else it is just an expression to the system. Glad to see this had been asked. – Timeless Jan 22 at 17:36

I think you will find that all this business about measurement and choice is just an approximation that happens when we try to separate the universe into observer and observed. The fact is that "collapse" violates unitarity, and unitarity is pretty well established, so I don't think lazy evaluation would work. Remember, there is more to the universe than photons and slits. How would you handle something like QCD, where you aren't even guaranteed to have particles?

That is not to say you can't simulate a universe. The known laws are quite deterministic and simple. They're just intractable with our computing power.

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"They're just intractable with our computing power." In particular, simulating our universe is intrinsically intractable, since that would be recursive. – PyRulez Jan 17 at 1:17

The phenomenon you describe in your first paragraph is the collapse of the wave function. The particle is initially in a delocalised state, and by interacting with it we localise it.

The interpretation of the collapse is a vexed issue with multiple different ideas floating around. I don't know enough about the interpretation of QM area to comment on whether any of the interpretations are equivalent to a computing universe. However there are interpretations like decoherence/many worlds that do not imply the universe does any computing. So I don't think much can be said about your suggestion at the moment.

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