For reference: https://youtu.be/RhIf3Q_m0FQ
I think I grasp the concept, but why is this something unique to quantum mechanics? It just seems like a well thought-out method of testing for a result without affecting the original variable. I dunno… then again maybe this is all over my head. Someone, please ELI5.
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*PS: Sabine is not super well respected in the physics community, because of a lot of controversial takes that she presents in her videos*
This is a bit tough to do in an ELI5, but I’ll give it a shot.
This experiment is *only possible* with quantum mechanics because of a funny thing that happens with superposition. When something is random (like a coin flip for example) you can kind of think about it as “happening at the same time”.
*I know the video has an explanation for what that means, but it is slightly misleading*
We actually have hard evidence that this happens. You might’ve seen the double slit experiment, where light forms a strange pattern with multiple patches of light. You expect that the light can travel through one slit or the other forming two bright dots, but the pattern they form is the pattern pattern you would get of two light sources interfering with each other, not one. In a sense, the single photon travels through “both slits”, then forms a pattern with itself.
Now a strange thing happens if you try to figure out which hole it moves through. You can do this by adding a light detector at each hole. What you’ll find is that you’ll know where the photon goes, but it will no longer form the pattern, since after the detector you know exactly where it will go. By measuring it, you’ve also interacted with it, and changed the result after the measurement.
In this experiment, the real bomb is acting like a detector, meaning it’ll affect the path of the light. If it’s fake, nothing happens because there’s no detector. If the bomb is real, the light either hits it or it doesn’t, so there’s no superposition (similar to the no pattern case). If the bomb is fake, it’s free to move through both (pattern).
What you can do is look at all the outcomes (yes/no explosion, real/fake bomb) and you’ll find that no explosion + real bomb and no explosion + fake bomb has observably different results (pattern vs no pattern), light travels through *different* paths in these two cases. Meaning you can tell if the bomb is real or fake.
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