Particles Definition and 1000 Threads

If we have charged particles having Brownian motion, would this motion be associated with (or produce) heat or electricity? Would it produce electromagnetic radiation (and if it would produce it, what type of radiation in the electromagnetic spectrum)? Could there be Brownian motion of charged...

https://www.theguardian.com/commentisfree/2022/sep/26/physics-particles-physicists Note: Please read what she is talking about before commenting.

https://physics.stackexchange.com/questions/273918/is-there-a-possibility-for-discovery-of-anti-graviton-i-e-the-graviton-antipar How can a graviton have an anti particle even though they are essentially the same thing? Same thing with the photon. Any help would be great [Mentor Note: The PSE...

In a paper by Bain (2011), particles are left with little ontological value because of the Reeh-Schlieder theorem, the Unruh effect and Haag's theorem. The author claims (and here I am copying his conclusion): First, the existence of local number operators requires the absolute temporal metric...

In the ongoing quantum interpretations and foundations thread vanahees71 explained to me that the wave particle duality has been explained by the model where the position of a particle is calculated according to a probability distribution traveling in space. Am I understanding this...

I feel like if something is massless it should be able to travel infinitely fast with any amount of energy. When you have something with mass, you would need an infinite amount of energy to push it infinitely fast, but if the thing you’re pushing is massless, you should be able to push it with a...

I am reading a popular-science book Reality Is Not What It Seems by Carlo Rovelli, one of the founders of loop quantum gravity. He writes: and and So basically, space (spacetime) is just another quantum field like all the others, and the quanta of this field is the nod. Nods have volume...

Homework Statement:: I came across the following in an online article. I am unable to understand how these elementary particles cause a force to exist. "Each of the four forces results from the exchange of force-carrier particles.". Above statement is taken from...

I studied physics in University a bit out of interest. Curious on how exactly one proves the existence of particles. If I look it up, often the most basic example would be the cathode ray experiment. It seems pretty simple to me, but in my eyes it does not prove the existence of particles...

Why do subatomic particles change what they do when observed? Does it matter who is doing the observing? What happens if a non-sentient robot does the observing? How does that compare with a sentient human doing the observing? Thank you.

I thought pentaquarks were already considered discovered? https://phys.org/news/2022-07-lhcb-exotic-particles-pentaquark-first-ever.html

Physicists say the Higgs Field is like syrup and slows particles down from the speed of light. Wouldn’t it be easier and more correct to say there are no particles, just fields, and the strength of the coupling of the electron, photon, quark etc. fields with the Higgs field determines their...

Hello everyone, I have recently joined a physics summer school, for which I have to do homework every day. But I couldn't manage to solve today's problem, so I'm seeking help from you guys. The question is about two particles moving on a one dimensional path. First one is at x=0 when t=0, and...

We know that if we take two particles and assume no external force is applied then by Newtons third law total momentum gets conserved after collision. If we take three particles and there is collision between them and no external force then the momentum is again conserved for each pair like in...

I have a problem with this Hamiltonian: two identical particles of mass ##m## and spin half are constrained to move on the surface of a sphere of radius ##R##. Their Hamiltonian is ##H=\frac{1}{2}mR^2(L_1^2+L_2^2+\frac{1}{2}L_1L_2+\frac{1}{2}S_1S_2)##. By introducing the two operators...

Hello all. I'm an undergraduate student looking to conduct an experiment with an isotope that undergoes beta decay. I am curious as to the degree to which the isotope geometry will reduce the energy of/deflect beta particles emitted from the isotope. By geometry, I mean the "shape" of the...

Hello guys, I’m studying Newton’s Mechanics at the first year of engineering, and I would like to ask one question about torque. In my book I found this statement ‘’ Given a system of particles, it’s always possible to determine a pair of forces which torque is indipedent from the pole chosen...

I have a rather general question about the definition of entropy used in most textbooks: S = k ln Ω, where Ω is the number of available microstates. Boltzmann wrote W rather than Ω, and I believe this stood for probability (Wahrscheinlichkeit). Obviously this is not a number between 0 and 1, so...

Is it possible to derive special relativity from the principle of quantum mechanics according to which particles of the same type are indistinguishable? For example, if it is not possible to distinguish particles of the same type then particles colliding in a train at constant speed should...

MCNP6 gives me a "10 particles got lost" error when I try to run the attached input file modeling a 3x3 fuel lattice surrounded in coolant. As I understand it, this error is usually related to the geometry/surface definitions of each component, but I'm unsure of what the source of the error is...

Pathria, Statistical Mechanics " ... classical system composed of noninteracting particles... .Now, if there do not exist any spatial correlations among the particles, that is, if the probability of anyone of them being found in a particular region of the available space is completely...

I saw that we can talk about the light as particles (photons ) or as an electromagnetic wave , the question is that do we represent other electromagnetic waves (like microwaves or radio waves ) as particles (like we do with light ) ?

I have a simple question. Do alpha particles from radiation arc and fall after leaving its source? Are these particles bound by the same gravitational laws as us?

[Pathria, statistical mechanics][1], pg2 ,when discussing ##N## particles in a volume ##V## "...there will be a large number of different ways in which the total energy E of the system can be distributed among the N particles constituting it. Each of these (different) ways specifies a...

Considering two interacting particles in 3d, the corresponding Hilbert space ##H## is the tensor product of the two individual Hilbert spaces of the two particles. If the particle interaction is given by a potential ##V(\mathbf r_1 -\mathbf r_2)## ,what is the corresponding potential operator...

Hi there, I'm a bit confused about the E=hf equation for mass particle(f for frequency), and Lorentz Invariant (E^2 -p^2c^2=m^2c^4). The question is, which energy is it? Total Energy- Kinetic plus Rest, or only kinetic energy. Now, if it's total energy, then you get that a particle at rest...

Using the equations mentioned under this question, I came up with following analysis and directions of velocities on either side of ##x_1##. Also, I'm not sure if there is an easier qualitative way to know the velocity directions rather than do a detailed Calculus based analysis?

My article has been published in Entropy . Abstract: Schrödinger noticed in 1952 that a scalar complex wave function can be made real by a gauge transformation. The author showed recently that one real function is also enough to describe matter in the Dirac equation in an arbitrary...

Generally, energy is ##U=9\times 10^{9} \times \frac{5\times 10^{-6}30\times 10^{-6}}{2+(10+20)\times 10^{-2}}=0.5869 J## <br/> After touching, they have charges ##q_1 and q_2 = 35\mu C-q_1## ##\frac{q_1}{10}=\frac{35\mu C-q_1}{20}## I was wondering where 1/10 and 1/20 coefficients come...

Disclaimer: This post is a 'Just-In-Case'; it is way out of my field and was not particularly impressed with the popular version. Others can better evaluate the research article. Mouth wash containing Cetylpyridinium chloride (a surfactant) does the job. Speculation is it may be a help in...

i do not know if the question about entangled particles has found mainstream answers; Suppose that pairs of maximally entangled particles are shared by Bob and Alice in a time independant gravitational field. Bob measures the spin in the direction of far fixed stars. There is a direction in...

Aerosol particles with an average diameter of 5 μm and a density of 1000 kg / m3 are spread to a room with a floor area of 20 m2 and a height of 3.5 m. How long does it take for all 5 μm particles to settle on the floor (dry deposition)? The answer should be 1 hour and 20 minutes.

I'd like someone to check that this solution is right, and if not, give me the point of failure and not the answer. Thanks!

Suppose we've an isolated box having ##N## classical distinguishable particles in it, the box being hypothetically divided into two parts, left and right with both parts identical. Its said that the probability of having the configuration of ##n## particles in the left side is given as...

When I first read the question, it didn't occur to me that these particles would ever meet or catch up with their neighbors. They are all traveling from one vertex to another with a velocity ##v## and a distance ##a##, all either clockwise or anticlockwise right ? The question says "Each...

(Apologies for a basic question) Do charged particles always have spin ? Maybe a better question is, are charge and spin always associated ?

I am stuck. Please ignore my handwriting. I am working on latex. All I am taking is x and y coordinates same of both particles. Yes they will meet at some time t.

My professor said that if I take 10^24 particles, for example, and I observe them for 1 years, I can say that their average lifetime is at least 10^24 years. I am not able to understand why, I though the law of decay is N(t) = N0*e^(-ta), so if after 1 year N(t) = N0, I can say ta ~ 0 , so tau...

When a heavier mass (or nucleus say) collides with a lighter one, it deflects through a certain angle which has a theoretical maximum. There are numerous derivations for this maximum angle of deflection ##(\sin\theta_{d_{max}}=m/M)## where m is the small mass and M the larger but none seem to...

Homework Statement:: Not homework, but I want to calculate the probability of different size spheres traveling through different size pores. Relevant Equations:: V=4/3πr^3 volume of sphere. Volume of 60nm diameter particle = 1.13x10^5 nm^3. Volume of 70nm particle = 1.8x10^5 nm^3 Hi all, this...

Here is something I don't understand which I expect someone here can explain. If one member of an entangled pair goes on a trip at relativistic speeds, there will be two different frames of observation, with two different elapsed times. The time frames can get off-set by years, over a long...

Transcript from "what the bleep do we know" the particles take up an insignificant amount of the-- of the volume of an atom or molecule, the fundamental particles. The rest of it is vacuum. Questions: If, inside of an atom is mostly space, how do we have stuff, that is made of atoms? Stuff...

The question is very simple: Is the flow of charge, or current, related to a closed path or there will be a potential difference without closed path to allowing the flow? I mean, If I have a battery that maintain 5V of potential difference through its terminal, I believe there is an amount of...

I set up an equation for the sum of all the potential energies and when cancelling out ##k## and ##q^2##, I got ##\frac{1}{0.05}-\frac{1}{x}-\frac{1}{0.05-x}=0##. However, this has no solutions, so I must've gone wrong somewhere. Could someone just give me a hint, not a solution, that would put...

I have this homework: consider the case of two spin half particles. Use the basis: |++>, |+->, |-+>, |--> to find the matrices representing the operators S^2 and S_z. My idea for the solution for S_z is: S_z=S_z(1)+S_z(2) where S_z(1) is the operator for the first particle ... etc So I...

Recently I've read more about virtual particles and at first I tought that there were only doubts that virtual particles are not interpretable with the help of uncertainty principle. Furthermore it can't be used an an "excuse" for the temporary violation of the conservation of energy. Can...

The other day I found a fascinating video on geometric algebra: At 34:50, after showing how to rotate a vector in three dimensions, he says, "wait a minute, this looks like a spinor from quantum mechanics. The way that spinors rotate is always said to be a part of so-called 'quantum...

I'd appreciate some clarification of this passage in the paper Spinning test particles in general relativity by Papapetrou, The definition is easy enough to understand, but what's the motivation? ##X^{\alpha}## are the coordinates of points on the worldline whilst ##x^{\alpha}## are...

Please excuse my physics ignorance. Can usable energy be extracted from alpha particles? Perhaps in a manner similar to a photovoltaic panel producing power when exposed to light? Thank you.

Are the typical energies of virtual particles lower than real particles?