Eli5: how is it possible for electrons to not be anywhere specifically until we take measurements and force them into a defined position?
In: Physics
Hi, actual physicist here, please do not listen to the other comments on here right now. They are completely wrong. I’ll edit this comment to have an actual explanation, but I just wanted to warn you about the incorrectness of the other comments first.
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In quantum mechanics, particles are actually waves propagating through “fields” in space.
Light is waves in the electromagnetic field.
Electrons are waves in the electron field.
These waves are spread out through space and don’t have a specific position, in the same way that water waves are spread out across the water surface and don’t have a specific position.
Now, imagine you set up some kind of detector, say a screen of pixels where one will light up if it interacts with an electron. You will observe exactly one of the pixels lighting up. The probability of each pixel lighting up is the square of the “height” of the electron wave at that point. After the measurement, the electron spread out as a wave from that one pixel position again, sort of like how if you throw a rock into a lake, the ripples spread out from that point.
That’s what we observe. We can describe everything that happens mathematically perfectly. What we *can’t* do is all agree on what that math implies about the universe.
One interpretation is that large-scale interactions with quantum systems (like your pixel screen with the electron) cause the quantum wave to suddenly “collapse” to a single point. This is the Copenhagen interpretation.
Another interpretation is that the electron wave continues normally, but the screen, your brain, and you all get “entangled” with the particle, so you only see the parts of the electron wave with the electron in a specific location, even though all the other locations continue to be part of the wave. This is known as Everettian or Many Worlds interpretation.
Another one is that quantum systems that get too heavy are forced to pick a single position by gravity.
Regardless of which interpretation is correct, we have *lots* of experimental evidence confirming that the other two comments I responded to are **not correct**. This is pretty far beyond an ELI5, but interference effects and Bell tests confirm that the electron *was definitely a wave* before measurement, and the electron didn’t just have a position we didn’t know.
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P.S. I’d recommend asking physics and math questions on r/AskPhysics or r/AskMath instead. There are *a lot* of confidently incorrect people speaking out of their asses about physics and math on ELI5
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