# electron

1. ### I How do we know the mass of an electron?

I've been researching the proof of subatomic particles given the fact that we have never seen them before. It has always been recognized that protons, electrons, and neutrons exist; but I question how we know for certain they exist. Across my studying I've realized that in 1897, J. J. Thompson...
2. ### I Why is a pair of an electron and a positron unstable?

We know that an electron and a positron will annihilate and emit gamma ray. But the electron and positron possess initial kinetic energy meaning that it is difficult for them to really collide in each other. Just like earth is not dropping into the Sun even with the gravitational pull. So I am...
3. ### I Electron wave funtion harmonic oscillator

As we see in this Phet simulator, this is only the real part of the wave function, the frequency decreases with the potential, so lose energy as moves away the center. we se this real-imaginary animation in Wikipedia, wave C,D,E,F. Because with less energy, the frequency of quantum wave...
4. ### B Electrons cannot sense electrostatic force?

Why there is not voltage or current just for 1ms if I connect a multimeter ground to the negative terminal of a DC power supply or charged capacitor? Why electrons in measure lead and DMM device cannot sense a bulk of electrons (or lack of it)? I tried with an 5kV DC power supply too. In an...
5. ### B Why can an electron go through PVC insulator

I connected a PVC insulated alligator clip test lead to a 12V (give 20V) DC power supply positive terminal and a multimeter. After that I connected an other one to the multimeter ground, and a third one to the power supply negative terminal. I turned the multimeter to DC V measure mode. When I...
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22. ### Electron Plasma to Muon/Proton

1. Homework Statement Cylinder electron gas with density of ne= 1010 and radius or r=1cm is inside magnetic field of B=104 Gauss. If we change the electron gas with (i) muon gas (ii) proton gas does the Drift Velocity change? 2. Homework Equations Boltzmann equation of density...
23. ### I Why are all particles of the same type identical?

Why all particles of same type identical? All electrons are identical to each other, all protons are identical..etc. It is as if they are copy pasted from each other! For me this is one of the biggest mysteries ever, why we don't detect more massive or less massive electrons? Is it related...
24. ### B In night vision equipment, how does 'information' transfer?

So I read a couple of explanations of how night-vision equipment works. Unfortunately I don't remember the sources but my recollection/understanding is that infrared light is converted into electrons and then in to visible light. So my question is how does the information by which I mean (the...
25. ### I How come electrons and phonons lead to the heat equation?

Phonons on their own lead to the common heat equation. One sees that for example in insulators or non doped semiconductors. However in metals (or conductors), the electrons are the ones that are mostly responsible for the heat transfer, which extremely surprisingly to me, is also of the form of...
26. ### I Understanding an electron's emission of electromagnetic waves

Hi to everybody ! I was thinking about something which confuses me about wave emission. The question is simply the following: Does an electron emit light when it accelerate? or just during its deceleration? or maybe when acceleration and deceleration alternates in some order? I'm not really...
27. ### B Does the size of the Universe change with motion?

This is a question I was looking at based on Relativity and John Wheeler's one-electron universe theory. https://en.wikipedia.org/wiki/One-electron_universe My question is this. The faster you move towards the speed of light, wouldn't everything in the universe contract to a single particle...
28. ### I Can one electron emit 3 colors at once?

When light is shown through hydrogen gas, three colors of light appear. The issue I have with this is that hydrogen has one electron, meaning somehow the electron has to be emitting all three of these colors simultaneously. This, however, would be impossible since a single electron can only make...
29. ### B Energy, What Is It?

I have a simple two-part question, or two simple questions. 1. What is energy? 2. What is charge? The charge I'm referring to is the charge on charged subatomic particles. And atom's charge is defined by the number of electrons and protons present in it. But an electron itself is called a...
30. ### I Electron speed and acceleration in an electric field

Hi everyone, I often work on a SEM, a type of microscope which is based on electron acceleration between an electron source and the sample you are working on. For this reason and since a few weeks I was wondering how an electron (in term of speed) behaves in a constant and linear electric field...