Like, I think rather than saying an electron exists in all possible states, isn’t it more like it doesn’t exist in any state yet? Not to say it doesn’t exist, but maybe like it’s in the US but in Puerto Rico so you can’t say it’s in a state…
Okay let’s take this for an example. You’re in a room, and you spin around more than you have ever before in your life. At some point when you stop, you will puke. Maybe you will puke on your door, or on your bed, or under the table. But you puke when you stop and your brain can’t adjust to the sudden halt. Spinning person ≈ electron, location ≈ where the puke lands. While the puke is inside you, it’s not puke, it’s stomach contents.
I’ve been watching some quantum mechanics videos and I’m not sure if I’m getting closer to understanding or further. What I explained above seems to make sense, but I feel like there was an argument somewhere in the videos that explains how “all possible states” is correct rather than the concept of state not making sense, and I can’t tell if it’s a semantic thing my analogies resolve or more likely I’m still very wrong about some part of this
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The ELI5 is essentially “it’s a debated topic”. The electron isn’t existing in all states at the same time, but it’s also not just non-existent, but nobody knows for absolute sure.
The best way to describe it I guess is that the most information we can have is a list of potential outcomes and probabilities for each outcome. E.g “puke on left of bed, 22%”. We physically can’t known if this state is the one that comes out until we look, and how we make sense of that in a real physical sense is essentially that we don’t know. We have some ideas (all event’s happen, we exist in a multiverse where our event happened), or that it is deterministic, but there’s a limitation by the rules of physics that nothing can know ahead of time.
It sounds like you’re ready for the talk.
https://www.smbc-comics.com/comic/the-talk-3
A “state” is like, “traveling north” or “traveling east”. A superposition is a state like “traveling northeast”, a combination of north and east. For someone living on a street grid like Manhattan, “traveling northeast” doesn’t make much sense, but it’s still true that “northeast” is a single direction, not “all possible directions”.
Likewise, quantum superpositions are single quantum states, even if that state doesn’t make sense to us in terms of classical physics.
Quantum Mechanics is hard and counter intuitive and unintuitive and downright nonsensical sometimes, so it’s hard to give an analogous answer, but I think a better modification to your example is that imagine while you’re spinning your eyes are closed and you do puke, you’re still spinning in a circle with your eyes closed, the puke could be literally anywhere, on the walls the floor the ceiling the cat, but once you open your eyes, the puke is where it is.
It’s the act of observation, the measuring, the assessment, it’s when you remove the wiggle room for other probabilities that you collapse the superposition into one position. Again it’s not a perfect example, but again it’s hard to do an analogy because quantum phenomena don’t behave in ways we can rationalize or understand, they’re operating on completely different principles.
It entirely depends on your interpretation. The copenhagen interpretation asserts that you should not make metaphysical assumptions as to what the model implies about reality, just “shut up and calculate” without additional philosophizing about what the math “means”. Other interpretations, such as the many worlds interpretation, takes the wave function as representing something that actually physically exists, though it is not as popular of an interpretation and requires unevidenced assumptions about the aforementioned “ontological meaning” of the math we use to describe physics.
Personally, i see the wave function as just representing our knowledge of how the quantum state evolves between measurements. It provides a statistical distribution for all of the possible quantum states of a system; any one measurement will reveal a single quantum state that falls somewhere along this distribution, and many measurements on identically prepared systems will reveal the probability distribution that we see in the wave function (some results being more likely than others).
Basically, the wave function just provides a mathematical framework that allows us to make extremely accurate “gambles” for what we will see upon measurement.
Quantum physics is one of the most mischaracterized fields of study in popular media, simply because making it seem more “weird” or “fantastical” gets more clicks/sells more books.
When viewed from the outside a quantum system has to be modelled as being in a combination of all possible states.
Not both. Not undefined.
Defined as being a combination of all possible states, with amplitudes corresponding to each.
Is this a real thing? Yes. You fire an electron at a barrier with two slits in it, there are places where the electron will not end up because the “part” that goes through one slit cancels out the “part” that goes through the other. There is no way to model this correctly without superposition.
This is not intuitive. It is not easy to understand via analogy. And no one is quite sure what is really going on and how this all works. It involves a bunch of maths. But the maths does work. It makes solid predictions for the real world.
“Nobody understands quantum mechanics” – Richard Feinmann
The thing about QM is that there are at least five different “interpretations” that are all consistent with the math. The most famous are the Copenhagen interpretation (the one where an object is physically in both states until observed) and the Many Worlds interpretation (splitting universes and whatnot).
Your description is consistent with the math, so it’s a valid interpretation of QM. As for ultimately which one is true, we have no idea. And as far as we know, there is no way to test it.
TL;DR: This is an active physics debate, nobody quite knows.
If you want to understand the hidden workings, this is the best video for it https://www.youtube.com/watch?v=F_Riqjdh2oM Unfortunatly its not that ELI5 as the best way to strip out the pop sci nonesense is to throw the linear algebra at you (but it is still approachable even if you dont know lin alg, they have pictures)
Basically it means that “This particle has a specific internal ‘state’ that means, when measured, it will collapse to either state with a specific probability (usually 5050)”
it means its oscillating between states really fast.
No.
Imagine you toss a coin into the air.
While it’s in the air we have no way of knowing which side it will land on. The coin spins and has the possibility to be heads or tails.
It’s only until it lands that we can observe which state the coin collapsed to.
Your vomit heatmap (what a phrase) is a pretty reasonable approximation.
I think where you’re getting hung up is the idea that one point on the map is “correct.” In the same way that you could make enough measurements of you throwing up to create the heatmap, if you could measure the electron in some orbital enough, you’d see the same heatmap. It’s also worth remembering that it often doesn’t matter – the exact position is largely irrelevant and most of physics and chemistry is only concerned with the wave function (heatmap) itself.
I would also caution when reading replies to complex science questions on ELI5, especially questions to do with quantum mechanics. There’s something strange about nuclear and quantum science where a large number of people who watch a single YouTube video feel qualified to answer, in a way that I don’t see with (e.g.) medical questions. For what it’s worth I’m a nuclear chemist, so I’ve studied this, but there are certainly more qualified people out there.
When you think about states and people in rooms, you are thinking about physical things. But when you get really small, physical attributes like size and shape don’t really translate well.
We think of an atom at being a bunch of marbles with smaller marbles flying around it. This isn’t right. Well, not in a meaningful way. It’s easier to describe the electron as a cloud, where there is some probability that the electron is somewhere in the cloud.
https://simple.m.wikipedia.org/wiki/Electron_cloud
As we get smaller, the less sense it makes to describe physical location, instead we describe it in terms of probabilities. This is what schroedingers big idea was – it wasn’t cats in boxes, it was how to generalize quantum mechanics as a set of probabilities over time, describe as a wave function.
https://en.m.wikipedia.org/wiki/Schrödinger_equation
This makes talking about quantum mechanics beyond this point really challenging. Everything is described in terms of advanced math that doesn’t translate well in to easy examples.
But here is an important thing to remember – these are models. These are ways of describing quantum mechanics, not the only way to describe quantum mechanics.
Super position is a way of describing quantum behavior as a function of equations, where position and place aren’t as useful as probabilities in describing quantum behavior.
You can get philosophical about quantum physics, and ponder what the fact that quantum mechanics being explained as a probability actually means, whether quantum particles actually have properties like a defined location and size, but that is not what super position and other quantum models are describing. They are simply models for describing what we observe and what we can derive.
It’s that it exists in both (or all) states.
Otherwise, we wouldn’t see interference patterns. This is key to how quantum computers work.
People love to make this sound mysterious, but it’s actually not.
A superposition is just wave behavior. The same kind of wave behavior you already know from sound, music, water, and so on.
When two waves overlap, you don’t get one or the other—you get both, added together. Their peaks and valleys interact. This is called interference, and it’s not metaphorical. Both waves are physically there in the same space, at the same time. They combine.
That’s what a superposition is: a state that’s made of multiple component waves existing simultaneously, not in a blend, but in a precise, math-governed structure.
Take a chord. You can think of it as a single rich sound, or you can analyze it into separate notes with different frequencies. Each note is still there, even though what you hear is their sum. That’s not a trick of perception—it’s a real combination in the pressure waves in the air.
Quantum mechanics is what happens when you realize that particles are really just special cases of waves. So they follow wave rules. That means they can also exist in superpositions—literally occupying multiple well-defined states at once, not probabilistically, but physically. Each state contributes a complex amplitude, and those amplitudes interfere. That’s how quantum behavior works.
They are in multiple partial amplitude states at once just like notes in a chord are both there contributing to a complex behavior that can’t be understood as the behavior of a single note. The problem arrises when you try to imagine a complex wave doing particle stuff. A single particle can’t be broken down into two components. But a wave can. These are waves not particles. And waves do wave stuff.
All of the deeply confused descriptions of quantum mechanics are a result of this fact. Wave mechanics are fully deterministic and fully local. And they fully explain everything we measure in quantum mechanics.