Ugh, the stupid “observe means observed by a conscious being” thing again. Any* quantum interaction will cause a collapse of the wave function. No conscious observer is required. When you do the experiment in a closed box and just increase the temperature to make it more likely for air molecules to interact with the laser you will also get a slit pattern.
*not really any interaction, scientists actually still aren’t sure what exactly constitutes a measurement, but we’re pretty sure a human is not needed
“Observe means observed by a conscious being”
Can something without consciousness make an observation?
Yes, for example a photodiode can make an observation. Or a computer, or a photographic film.
That makes sense.
Would that also mean if a tree falls in the forest it always makes a sound because there’s always “someone” around to hear it? It sounds like we could say that the air or ground is “observing” the sound waves or impact made by the collision?
“Observe” in the double-slit experiment means placing detectors in each slit. Once you do that, the particles start acting as particles only. Without detectors you get the interference pattern. Doesn’t matter in either of the two setups if an actual human is looking at it or not.
Observer in this context doesn’t mean consciousness, but things such as detectors. If humans were replaced by robots and the robots did the same experiment, they would still see the interference pattern. It’s a common misconception that “observer” in the context of the double slit experiment means being observed by a conscious being.
Exactly. Or, you could just buy into “many worlds” and the idea that your brain and all the quantum particles that comprise it just join in on the laser beam’s wave function. (That’s an oversimplification but close enough)
Just like there’s no reason to believe the earth is at the center of the solar system, there’s no reason to believe that human consciousness is a fundamental part of quantum mechanics.
It’s been forever since I learned about this experiment in school. How TF did they measure the unobserved state, since measuring is an observation? Was it indirect measuring?
You don’t! You observe the result. When no interaction happens the resulting pattern is described well with wave functions. If interaction happens to determine which slit it is traveling through the double line result is seen and can be described by mechanical functions.
This “we have math for both results” for interpreted to “has properties of both wave and particle”. Which I guess was one press release away from n"it’s both and depends on if I’m looking!"
The film on which the interference pattern is made is, in a sense, an observer. But the observer that most people mean is what was added after the wave-like interference pattern made researchers ask “okay, but which slit did the electron go through?” and they put a detector near the slits to determine an answer to that. When they did this, the wave function collapsed and the film no longer showed an interference pattern, but two bands, which would correspond to an particle-like electron going through either one slit or the other.
Could the whole thing be misconstrued, and just the proximity of the sensor be what is causing the wave collapse, not the observation?
Agreed, but I’m still getting a vibe of that statement being correct at some level, from some point of view.
The nature of reality at the smallest scales is slippery, and it is still a fact that simply observing/interacting/measuring it has an effect, that layers of reality at their “pixel level” are blurry.
And it is absolutely astonishing that we as a species have developed the tools and know-how to reach this understanding.