We state that electrons are subatomic particles with no known subcomponents. We discover that these electrons behave as waves. We also discover that sometimes, these electrons behave as point-particles. We conclude that they're the both at the same time. This, to me, sounds nonsensical. If this happened in math, and one discovered that 1 = 2, one would not go around saying that we have one-two duality, would we? No, we would question the axioms that we used to perform our calculations. If one-two duality is an outcome of those axioms, we should not accept one-two duality, rather we should reject the axioms! Yet, in physics, this does not seem to be the case. Why? Why is wave-particle duality accepted, rather than the axioms rejected? And what are the axioms in this case? Well, it's the first line in this question. We assumed electrons have no known subcomponents. Well, clearly our experimens show we're wrong. They do have subcomponents, and when the wave-like behavior of electrons occurs, it occurs precisely because of interactions between those subcomponents that we are not familiar with and therefore cannot understand. So what am I missing? It seems like physicists have accepted this bizarre notion of wave-particle duality that even Einstein thought was an embarrassment of physics,  rather than consider that some premises may be wrong and it is those wrong premises that lead to the wave-particle duality.
24597
I often hear about the wave-particle duality, and how particles exhibit properties of both particles and waves. However, I wonder, is this actually a duality? At the most fundamental level, we 'know' that everything is made up out of particles, whether those are photons, electrons, or maybe even strings. That light for example, also shows wave-like properties, why does that even matter? Don't we know that everything is made up of particles? In other words, wasn't Young wrong and Newton right, instead of them both being right?
102374
I have been reading/learning about the double slit experiment, its implications in quantum theory, and how it explained that “particles” can behave as both waves and particles.   I know that the wave function is a probability of the location of the particle, and that shooting the electrons through the double slits causes an interference pattern associated with multiple waves. This, though not making intuitive sense (in relation to how anything can even exist as a wave), is something I can follow.   However, I have read/heard that an “observer” collapses the wave function into a single point. This is what caused the electrons to actually show up on the wall behind the slit; however Feynman (admittedly, as a thought experiment) suggested that putting an “observer” prior to the slits would cause the electrons to fly through as particles, and leave no interference pattern on the back wall.   What is an “observer”? How and why would the electron “know” it is being observed and therefore cause it to change behavior?
9359
What does a  wave look like? Are de Broglie waves transverse or longitudinal?   Can they be polarized?    What about the de Broglie wave of a ground state neutral spin-zero Helium 4 atom?   What experimental evidence do we have that supports the detailed nature of a de Broglie wave?     I have always assumed that de Broglie waves were mathematically  identical to electromagnetic waves, but I just realized there is no basis for this assumption, and in fact it must be false, unless there is an analogue to both the magnetic and the electric components of the electromagnetic wave.  So what does a de Broglie wave "look like"?
111205
When I was in school, I learned (from Democritus) that an atom was  similar to a solar system, with the nucleus being the sun, and the  electrons being the planets. Of course, there are some differences:    The "sun" isn't a single entity, but a collection of protons and nuetrons.  Two planets can share an orbit (which might be possible in a solar  system too, but it doesn't happen in our solar system).    Is this model still valid? Here are my problems with it:    In "Surely You're Joking, Mr Feynman", Richard Feynman implies  that electrons are more a theoretical concept than real objects.  I have trouble understanding atomic bonds (ionic and covalent) in  this model.  I also have trouble understanding electron "orbit jumping" in this  model, as well as several other things.    Is there a better model for someone learning this for the first time?
82890
The quantum-mechanical model of atoms was derived from Heisenberg's uncertainty principle, which states that the position and momentum of a particle cannot both be determined to an arbitrary degree of accuracy. In order to understand the distribution of electrons in an atom, the momentum of an electron in the uncertainty principle is converted into its energy. The principle becomes &quot;we cannot determine both the position of an electron and its energy to an arbitrary degree of accuracy&quot;. The idea that electrons exist in orbitals comes from the solving of the Schrödinger equation, which yields the principle quantum number, the angular momentum quantum number, the magnetic quantum number, and the spin quantum number. For each atom, a combination of the first three Schrödinger parameters specifies a unique electron orbital. It is noticeable that the Schrödinger equation simplifies the uncertainty principle to the extent that we are only uncertain about the position of an electron, but not its energy anymore. Each electron orbital represents a probability distribution map of electrons that fall under it. Theoretically, we can find an electron that falls under a given orbital at any position within the probability distribution map that it specifies. But the problem is, each orbital has a fixed energy value. No matter where in the orbital we find the electron, its energy does not vary. In other words, when we look at an atom and want to determine the position and energy of one of its electrons, we assign it to an orbital. The contradiction is that as soon as the electron is assigned an orbital, we fix its energy, and the only indeterminate variable is its position. So, does electron orbital theory contradict the uncertainty principle, where there are two indeterminate variables? A very concise version of my question: the Heisenberg uncertainty principle implies that we cannot simultaneously determine the position and energy of an electron. But if we divide the outer space of an atom into electron orbitals, like the electron orbital theory does, and assign each electron to an orbital, we wind up being able to determine the energy of each electron!
42606
According to :     The electron has no known substructure. Hence, it is defined or assumed to be a point particle with a point charge and no spatial extent.   Does point particle mean the particle should not have a shape, surface area or volume?  But when I searched Google for the "electron shape" I got many results (like  and ) that says electrons are round in shape.
65161
In a normal atom, there is a limit of 2 electrons per obital due to the Pauli-Exclusion principle. I have seen people talking about replacing an electron with a muon, but since muons and electrons are distinguishable, would this then allow 2 electrons and 2 muons to occupy the same orbital, or would only 2 leptons be allowed to have the same set of quantum numbers?  For example, would a Beryllium atom with 2 muons and 2 electrons use only the 1S orbital, or would the 2S be used as well? Spectroscopic methods should be able to distinguish between the two.
53723
We know that there is uncertainty principle, so question: can we ever measure wavefunction of particles? I do not think this is possible, but I am not sure. I guess that everything is probabilistic. (that's why, I believe, we have sigma level when we say we discovered some particles...)
68703
I've always hit two big stumbling blocks in conceiving of the proof or disproof of  as being even valid idea, let alone an answerable question... I feel I must be misunderstanding some very fundamental things.   Quantum mechanics is deterministic, ignoring the bit where we take our complex number and fudge it into a probability. We use computers to make calculations to provide the predictions of quantum mechanics - how is this not itself a hidden variable theory?   From what I understand the famous Bell theorem and work around it doesn't disprove hidden variable theories, just one specific flavour of them, and even then I am not convinced. I feel like I must be missing something again, because this result seems to me in no way profound... although it certainly fits into the picture of the EPR 'paradox' and is a good demonstration of the validity of QM.  I guess the crux of my problem is that this 'area' really addresses wave function collapse and the problems it causes, but I don't see the need for some collapse mechanism to begin with... again I feel like I am missing something really fundamental.  Apologies if this is a bad question. I have had a look around and there are similar questions, but I don't feel that either of my points are addressed...
102120
I'm going mad about the problem.  I really don't understand why do electron have 1/2 spin number, why they are not actually spinning.  I can accept that the electrons have their own magnetic field, which is certain, but why do they have $\hbar\sqrt3/2$ of angular momentum, and I don't know what the heck is spin number.  I've read the definition of  and  more than a hundred times but there is no betterment. I've smashed my head in my desk more than a hundred times either.  My question is the title. Why can't I just think the spin as rotating?  What I've saw recently,     electron's hypothetical surface would have to be moving faster than the speed of light in order for it to rotate quickly enough to produce the necessary angular momentum.
30842
In our current theories all hadrons are made up of quarks and gluons.  This view reduces considerably the big family of hadrons by providing a very logical structure in which all quantum properties values of the hadrons are originated from the valence quarks' quantum properties. But since they cannot be observed isolated, in the sense that electrons or positrons can be, the theory assumes color confinement is just part of the game.  However actual calculations of QCD use a view where they are quarks and gluons are distributed in a space-time volume, which is needed to describe much of the rich phenomena of high energy physics.  But all of this makes me wonder:   Are quarks real and elementary? I mean, is there more evidence supporting that they are more than just a model that works?  Since hadronic matter cannot by split into pieces smaller than the smallest hadron, couldn't reality be explained also by a model where all observable hadrons are the elementary ones, which follow rules for transforming into other ones, etc.?  By the way, this last idea was already presented by Hagedorn on his very famous known paper, in the end where he tries to give a phylosofical point of view to his model, so I wonder why was it discarded.
12363
Louis de Broglie said that electrons are waves. But how they repel each other?
29610
I know plus pushes another plus away, but why, really, do they do that? On the other hand, molecules of the same type are attracted to each other. I find that weird.  I do know some stuff about four universal forces. But why in general the general "rule" is that opposite charges pull each other?   Yes, I do realize this could be connected to very basic stuff that science is still trying to figure out, and can be traced to the Higgs,  but still, there must be something to tell.
75699
Is there any mathematical relationship between matter wave (or de Broglie wave) and wave function?  Also, does each type of particle (e.g. photon, electron, positron etc.) have its own unique wave function?
121205
According to various sources on the web, it seems like the general concensus is that there isn't actually any wave-particle duality with quantum particles. For example,  implies that diffraction patterns in  were interpreted as wave interference due to apparatus limitation at the time they were first performed.  Does this mean that all those sources and animations showing two waves interfering are simply incorrect, classical conclusions which don't have anything to do with (quantum) reality?  What's actually the most confusing is that most sites which state that it is now possible to pass individual photons through these slits, also claim that these individual photons somehow interfere with themselves resulting in the observed patterns. That seems like a rather thin explanation, doesn't it?  So, is there actually any need to use wave interference to explain the phenomena, or can we simply state that the pattern is probabilistic in a certain way, without involving the "spooky" explanations?
45644
I understand that assuming light is quantized implies that if a lower energy interacts with  metal, it is possible that that quanta will not have enough energy to eject the electron. What prevents two quanta from interacting with the electron at the same time, though, and summing to have enough energy to release the particle. Indeed, what if two separate light rays of the same frequency impact the electron, why can't that free it?
61421
I'm still struggling a bit with some ideas around double slit experiments. One that keeps cropping up for me is the role of observers.   Imagine a classic double slit experiment with a hidden observer who has arranged an apparatus to detect which slit the electrons are passing through. This person and their measurements are hidden to you and you have no interaction with them.  So the question is, do you see an interference pattern or not?  Additionally: And if the answer is Not, then is the reason because they "disturbed" the electron (by say firing photons at them) or is it for another reason? And if it is because they "disturbed" the electron, then how is it that unobserved electron's are not disturbed since they certainly interact with other objects, for example other atoms in the matter around the slit(s) will feel a slight gravitational tug as it passes through.