Probably not well worded (bad at Physics!)
In: Physics
So you’re talking about the “Many-worlds interpretation” of the double slit experiment.
This is the idea that individual particles act like waves because they are able to collide with themselves in a parallel universe, so you get a wavelike pattern instead of just a single particle that goes in a straight line.
This theory isn’t really accepted though as it doesn’t have any way to explain gravity. Linking gravity to quantum physics is currently a big area of research in physics.
There are a number of competing theories about what happens on a quantum level. There’s what you’re suggesting, the Many Worlds Theory, where every possibility is accounted for in timelines that we can’t experience, but there are two other bigshots that take up a lot of the stage.
We have the Copenhagen Interpretation where particles are undefined probability waves until the moment that they interact with a field or another particle, causing the wave function to collapse into a single defined state.
The more recent addition is Pilot Wave Theory where particles are always defined but they can only exist in certain states or locations, as dictated by the quantum wave function. Interaction alters the wave function, and the particle ends up following this new path.
All three are enticing theories but break down in unique ways when you look too closely under the hood. As things stand, they can all be valid with certain tweaks that we can’t figure out right now. At the same time, though, they can’t be used as a definitive model for how the universe works.
So, to answer your question, the double slit experiment doesn’t show that there are constantly splitting universes. It only shows that there’s something weird going on at those scales and that Many Worlds might be the way to explain it, if we can somehow prove it.
No, it doesn’t do anything of the sort. All it does is demonstrate wave-particle duality. In other words, all it does is demonstrate that quantum objects sometimes act like particles and sometimes act like waves. There’s nothing in there or anywhere in quantum mechanics that leads to any conclusion that there are alternate realities.
In fact, there is no serious interpretation of quantum mechanics at all that has anything to do with alternate realities. Many people misinterpret the Everett many worlds interpretation to be about alternate realities, but it does not mean that in any way.
Just to add to all the great responses – now you’ve read the explanations, look up a video on youtube on the subject too. I’m sure there will many valuable vids on the experiment.
The double-slit experiment is a good demonstration of some key parts of Quantum Mechanics. In it, we see some ‘non-classical behaviour’ like ‘wave-particle duality’ and how that raises things like ‘the measurement problem’, and so on.
We see plenty of other evidence for Quantum Mechanics in other experiments too, but the double-slit-experiment (especially when done with 1 photon at a time) is one very clear/pure example, and so is a convining example that Quantum Mechanics must have something right.
Once you accept that Quantum Mechanics is (at least approximately) correct, it does raise questions as to what the results of the theory *means*. The ‘measurement problem’ technically doesn’t need to be solved for us to be able to use the theory; we can still ‘shut-up-and-calculate’ and get useful and correct predictive answers (to help with other expimernts or technology) without knowing why or how it is correct, but the meaning or metaphysics remains mysterious.
So, there are philosohpical ideas that try to answer the ‘measurement problem’ and thus attempt to explain a bit of the ‘why’ behind Quantum Mechanics.
* You may have heard of the idea of Quantum Mechanics resolving to chance in a ‘wavefunction collapse’, like you have a 50% chance of measuring a photon over here, and a 50% of measuring it over there, and that randomness is just part of reality. That’s one possible interpretation (the ‘Copenhagen interperetation).
* You’re talking about the ‘Many Worlds interpretation’, where instead of imagining some true randomness to a single world, we instead imagine every possbility happens. And one way to allow for that is to imagine that new worlds are generated to accomodate each possibility, i.e. the universe is split/cloned.
* There are also other interpretations. I think one is called the ‘handshake’ and another is ‘superdeterminism’.
These different interpretations are difficult (and perhaps in some cases, impossible) to even imagine testing, let along actually deigning an experiment around (I think I’ve heard arguments that perhaps ‘superdeterminism’ could realistically be tested, but tbh I don’t think I understood the argument so I can’t say whether that was valid or not).
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So, in summary, it is not the case that the double-slit experiment confidently shows that the universe splits with each measurement.
However, the double slit experiment does make a compelling case for Quantum Mechanics, and that raises the “measurement problem”, and the “many worlds interpretation” is one proposed answer to the measurement problem.
We could perhaps phrase it as something like:
>The Double-Slit experiment shows that we need an interpretation of Quantum Mechanics, but it doesn’t help point to which one to pick. You could pick the Many Worlds Interpretation instead of some other interpretation, but we don’t have any evidence that helps us know which interpretation to pick.
As I understand it (and I’m not an expert), as popular as it is in popular science, the many worlds theory is generally seen as one of the more unlikely explanations for quantum phenomena among various competing ideas, because it’s not falsifiable.
The double slit experiment shows a photon acting in two normally exclusive ways, leading to an “impossible” outcome. It’s showing as a very wierd aspect of this reality.
By definition, if we can observe it, it is by default, part of this reality. Just a really wierd part.
As I said, I’m no expert, so if any physicists who understand the maths behind manyworlds can either confirm or set me straight in any misunderstanding, please do.
Im going to be wildly reductive in explaining this, but are you talking about the double slit experiment where photons are shot through two slits and create five slits on the wall behind it?
That proves that light particles move in “waves”
As in if you where to set up a similar experiment using water and two slits it would create a similar distribution on the other side.
I think what you think you are referring to is that an electron can only be measured. Meaning, we can only know where it is by looking at it. If we had two possible outcomes of where it could be, theoretically it would be in both states at the same time until we measured it.
Which have lead some to conclude that if it is at both places theoretically at the same time then with every choice to measure it those two possible out comes must become true in different realities.
That’s a leap. The implications of the double slit experiment are important, but not that consequential. You can take the ideas that come out of those results, and after a long path, get to a theory about multiverses and alternate realities, but it’s like saying an acorn is responsible for the life changes of the person who wins a lottery on the ticket made from the paper produced from the tree.
I think of many worlds theorem like Schrödingers cat; a conclusion that is deliberately absurd, and which just highlights that we lack a deeper understanding of what is going on. Schrödinger’s cat showed the absurdity of applying quantum physics to the macro scale, many worlds shows the fallacy of thinking of photons/matter as either a wave or a particle. It’s something else entirely
That just shows that light behaves like a wave.
Alternate realities ? I’m sorry I don’t really understand the question lol
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