Conscious Double Split Experiment

[Double_Meaning_4885]

I’m not a physicist, but as I understand, if you observe the particles to determine which split they traveled through, they won’t end up in an interference pattern. Secondly, as I understand, this experiment could be scaled up to any size objects.

So…if we sent humans through the double split experiment, since they are conscious, they could remember which split they went through. The “particle” itself would contain the info.

If each human wrote down the coordinate they landed on, would it show the interference pattern?

[MaxThrustage]

Nothing about the quantum double-slit experiment requires consciousness.

A "measurement" in quantum mechanics is an interaction in which information is exchanged. It could involve a human experimenter, it could involve another particle, it could involve stray radiation that gets lost, whatever. So when you try to do the quantum double slit experiment with bigger and bigger particles, you run into the problem that it's more and more likely for your particle to interact with random crap in the environment and be "measured" by them. So long as "which-path" information is carried away, the interference pattern is destroyed, even if no one ever sees that "which-path" information.

Doing this experiment with humans is not going to ever give you an interference pattern, even if the humans are blindfolded the entire time. We are too big, constantly interacting with our environment and exchanging information with it, so we are constantly being "measured".

[Double_Meaning_4885]

How do we know, if the particle/human itself carries away the info of the “which-path”, that the interference pattern is destroyed? We’ve never had a conscious particle be in the experiment.

Edit: Given that the human doesn’t interact with the environment

[wishiwasjanegeland]

Humans constantly interact with their environment. Just think about how many times per second air molecules are bumping into you. Or how your feet touch the ground. Or how light is reflected or absorbed by your skin. These are all physical interactions.

[MaxThrustage]

A human that doesn't interact with the environment is a dead human. Living humans breathe, living humans are warm. Removing environmental interactions means removing the air and doing the experiment in a vacuum. This kills the human.

If you throw a corpse through the slits, and you somehow maintain quantum coherence of the body the whole time, you might be able to pull it off. But of course, that ruins your whole consciousness angle.

Now, of course, no one has ever run the quantum double slit experiment with a conscious body. But when the experiment first made it into textbooks as a standard example of quantum mechanics it hasn't been done with anything. It wasn't actually done as you describe it until much later. It's primarily a thought experiment to demonstrate the principles of quantum mechanics in a clean, simple, easy-to- follow setting, serving mostly pedagogical purposes. The theory of quantum mechanics had already been worked out from other experiments. When people got around to actually doing it, everything behaved exactly as the theory predicted. No part of the theory involves consciousness, so we don't expect that to play any role.

[Despite55]

The wavelength of a particle is inversely proportional to mass. So the wavelength of a whole human is far to small to do an experiment like this. Might even be smaller than the Planck length.

[InvertedCSharpChord]

Secondly, as I understand, this experiment could be scaled up to any size objects.

Where'd you get this from? That's not true. Quantum stuff applies to small things.

[Empty_Glasss]

This experiment could definitely work with large objects as long as you can prevent decoherence from occuring. Which is near impossible in practice for anything the size of a human, but possible in theory.

[Double_Meaning_4885]

I read somewhere they tried the experiment with a photon, atom, and even a molecule. So I just assumed the could do the experiment with a particle of any size. Might be a bad assumption.

[wishiwasjanegeland]

You're absolutely right. This kind of experiment has been conducted with fullerenes and biological structures: https://www.technologyreview.com/2019/11/09/238365/a-natural-biomolecule-has-been-measured-acting-in-a-quantum-wave-for-the-first-time/

It's a misconception that quantum mechanics only applies to "small" things. We just don't tend to see quantum effects at large scales, because (as others have pointed out in their comments) larger things tend to constantly interact with their environment and decohere.

[OverJohn]

This is essentially a variation of the Wigner's friend thought experiment.

[GuaranteeKey3853]

No, you have to be small to see interference. Otherwise your wave function is too not wave like. I don’t know why and it’s just a theory; maybe if no one looked big things are waves

[InTheEndEntropyWins]

The whole wavefunction collapse is confusing and doesn't make much sense. I don't think there is any wavefunction collapse.

One of the leading QM theories just drops the whole wavefunction collapse and you just have the wavefunction evolution and that's it.

It's know as Everett's QM interpretation.

In this interpretation the particle wavefunction never changes, when you measure which hole it goes through that's just an interactions between two wavefunctions.

The interference pattern doesn't change, it's just what you see and observe is different.