Particles Definition and 1000 Threads

Something about collisions has been bothering me. Let's say I have 2 particles with equal mass: one is moving at velocity v towards the other particle. Kinetic energy and momentum is conserved during this collision. However, I have a question: what is the acceleration of the particles during the...

I was just reading the article about “cosmic rain” here and they talk about these very high energy particles striking a detector. But as I understand things, these have to be waves, not particles, put up a double slit and these things will go through both as waves (and since they do not know...

Erebon theory is a novel explanation of dark matter recently invented by Roger Penrose. Erebons are scalar particles of the order of a Planck mass which can only interact gravitationally. When erebons decay, they release their energy as oscillating classical gravitational waves on the order of...

I may be getting these Thread Levels wrong. I get the impression that they apply to my level of knowledge such that someone else might be able to give an answer that I might be able to understand rather than the level of knowledge required to answer the question. Rest assured I am quite stupid...

I have some questions about quantum entanglement 1 - Why is this phenomenon considered so surprising, if it just states conservation of quantities (e.g. spin, momentum) and we are already accostumed with conservation of quantities in classical physics 2 - Suppose we have, say, a hydrogen...

Homework Statement Hi, I'm trying to familiarize with the bra-ket notation and quantum mechanics. I have to find the hamiltonian's eigenvalues and eigenstates. ##H=(S_{1z}+S_{2z})+S_{1x}S_{2x}## Homework Equations ##S_{z} \vert+\rangle =\hbar/2\vert+\rangle## ##S_{z}\vert-\rangle...

In Carrolls notes on General Relativity, it is said that the general formula for finding the spin number of a particle is $$\frac{360°}{\theta}$$ where ##\theta## is the angle of rotation, after which the state of the field describing the particle returns to its original state polarization. He...

Hi How can find the resonant frequency of small objects like dust particles? What factors affect the resonant frequency? And is resonant frequency dependent on size? i.e. if the resonant frequency of 1 cm3 of glass is some certain value, would it be the same for a larger size?

Homework Statement Homework EquationsThe Attempt at a Solution The two particles are supposed to move along the same line. And the two radius vector could be anything. Is this correct?

I was just wondering if macroscopic things like a book or even a human can travel to another universe, like quantum particles.

There is no math in this one! I just wanted to know if I had the idea correct. Homework Statement If I have two positively charged particles at a distance between them that a field is produced between and around them, will test particles that repel away be solely a function of their distance...

Full disclosure, I am a creationist, but i want to know the finer points about the big bang and the creation of the universe. So we know that the formation of new rock from lava doesn't make them "day zero" rocks, ie they still would be considered aged when we do radiometric dating. So we know...

I've been experimenting with my own N-body simulation and I've found a seemingly unsolvable problem. When 2 particles cross paths exactly the peak velocity varies according to how close they are at their closest point and they either fly off the screen or slow right down, I can add an offset to...

I'm not sure if this is the right place for this question., but I'll ask anyways. So in particle accelerators when the protons "crash" particles are created because of the extremely high amount of energy(example of e=mc^2?)? Is that correct? Also, where do these particles come from? The Higgs...

Homework Statement A group of particles is traveling in a magnetic field of unknown magnitude and direction. You observe that a proton moving at 1.50 km/s in the +x-direction experiences a force of 2.25 x ##10^{-16}##N in the +y-direction, and an electron moving at 4.75 km/s in the -z-direction...

I am proposing a piece of equipment a bit similar to Crooke's radiometer with the aim of using kinetic motion of air particles to rotate the mill, without need for an external source of EM radiation. Instead of flat vanes as in Crooke's radiometer, I propose 3-dimensional vanes in the shape of...

I don't know if I am right, but I have read about how some particles do not even exist until measured. How would we know this?

This is the problem I'm trying to understand: Consider two particles with spin 1 without orbital angular momentum. If they are distinguishable, from the rule of addition of angular momentum applied to spin, we'll have states of total spin j=0,1,2. If we have, however, identical particles which...

Thread title edited by moderator. I've not seen any reports from CERN concerning the detection of any putative supersymmetric particles. Is the absence of such detections a problem?

In quantum mechanics there is a no cloning rule, so you cannot have two things that are exactly the same. So that must mean that all particles are different. So what kind of unique properties can individual electrons or protons have?

So, I found this document that talks about rf cavities at lhc https://home.cern/about/engineering/radiofrequency-cavities Can you please explain me what i underlined Means? If i understood when the particles achieve the velocity the scientist want them to achieve they get into the cavity when...

In trying to understand the relationship between Higgs particles and gravitons, I would like to pose a question on hypothetical question: What would happen if you increase the Higgs field around a planet? It seems it would mean its mass increases, which would mean its gravitation increases...

When they talk about information falling into a black hole, are they referring to the basic defining parameters of the particles falling into the hole?

If gravitational force is caused by a particle (tensor boson) which is massless and so travels at c, why doesn't matter ever exhaust, or even seem to reduce, its supply of these particles?

Hello, I am a curious layman, so I might have some misconceptions. I have been pondering some questions, and I was hoping someone might be able to either confirm, or explain this. What I am wondering, if I am understanding this correctly, is why atoms do not experience entropy? If this is true...

Hi. I found following exercise in a high school textbook: "Compute the entropy change in following process:" The solution is "The number of particles decreases from ##N_1## to ##N_2=N_1/2##. Hence the entropy decreases by $$\Delta S=-k\cdot N_1\cdot \ln{2}\enspace ."$$ I can't quite follow...

I have an "unidimensional" box with two identical particles in. My question is , Does it matter in which total spin state is my total function? I mean , if it is a singlet or triplet , one is antisymmetrical and the other is symmetrical, but I only integrate the function in the spatial...

I'm curious if there have been any variations to the double slit that specifically looked at whether the particles behavior was determined by the computer keeping the data or if a consious person was there to see it. For example what I had in mind was having an isolated room where the computer...

If a particle can potentially be transported to any place in space limited only by the speed of light, does that potential amount to an expansion of space? And another question: Does it make sense to define space as any place a particle could go to?

Homework Statement Consider the process of decay of a muon into one electron, one electron antineutrino and one muon neutrino using the Fermi theory. Assume the matrix element is, ignoring the electron's and the two neturino's masses, |\mathcal{M}|^2 = 32G_F^2(m^2-2mE)mE being E the electron...

can lorentz contraction be measured via quantum entanglement with one of the entangled particles moving near the speed of light? would the particle in motion be affected by lorentz contraction? if so, would the particle at rest follow suit and appear affected?

Do elementary particles have inertial mass in the same way composite objects have? If yes, does it have an impact on the motion or on the forces that act on them?

hi everyone. i'm only 16 so please beer that in mind. I've been doing some reading around and have come across the idea that light slows down in an dense medium as a result of the photons moving tough other particles with a slight delay however they retain all factors about them selves apron...

source = http://scienceblogs.com/principles/2012/03/14/entanglement-is-not-that-magic/ It's not clear to me from the above whether this experiment is repeated on the same entangled pair of photons, or a different pair each time. Also, thanks to SR, I have trouble with the "when." Would the...

I am aware that according to the Standard Model of Particle Physics, fundamental particles such as electrons and quarks are treated as point-like particles. However, if fundamental particles are indeed 0-dimentional points with no spatial extent, it creates problems (i.e. fundamental particles...

I see they finally counted all the particles in the universe, it's10 to power of 80 They also counted all the planets: 10 to power of 24 and also counted all the stars: 10 to power of 24 and also counted all the atoms in the Earth: 1.3 x 10 power of 50 Good work everyone! Now, I'm trying my...

Suppose we have two charged particles on the laboratory and two observers A and B. ##A## is inside one of the charges (never mind how) ##B## is sitting at the laboratory In the lab reference frame we accelerate the particles. According to ##A## there will be only electric attraction or...

Gluons are often depicted as fundamental particles in the Standard Model. But in looking at their mechanism, it seems they are not really fundamental particles in the sense that they are fundamental, indivisible, building blocks. They are mesons- a composite quark-antiquark pair, where their...

I have a question which puzzled me when I was reading up about auroras. When talking about the interaction of the solar wind and the Earth's magnetic field, the book said that "particles are accelerated along magnetic field lines towards the earth" That didn’t sound quite right, as I was taught...

Typically, particles are said to be excitations of quantum fields. My question is whether fields can be derived from particles. Perhaps virtual particles can be summed up in some way to produce a field, for example. Any theories on this? Thanks.

Say an electron is fired with the same De Broglie wavelength as blue light. If the electron were to reach your eye, would you see blue, or would something else happen?

How would a physicists expect a perfect relativist quantum particles simulation to look like? Can anyone give a description of its functionality? Let's say for example, someone would program a simulation, composed of a 4D space-time diagram. Within this simulation are a large amount of quantum...

1. Homework Statement I did an experiment to separate different sizes of starch particles (range of size 1 µm to 10 µm). I mixed the starch powder with water in a long cylinder. I have to create model by using long cylinder to separate those starch particles according to their size (<1µm...

If i have the momentum of the particle, could I measure their energy ? I'm talking about particles in a beam, they are moving in a relativistic speed.

When we rotate a disk, can this process be fully explained by looking worldlines of the particles the rotating disk is composed of, hence their x,y,z,t position "as time passes", or do particles have some kind of "facing direction", hence also spin(not the quantum mechanical notion of spin)...

http://www.nature.com/news/not-quite-so-elementary-my-dear-electron-1.10471 So when the electron is in the material, it separates into 3 different quasiparticles. But then it says that they cannot exist independently outside of the material. So does that mean the 3 quasiparticles are always...

Plain old standard model baryons, but 5 at the same time, and with crystal clear peaks in the decay to ##\Xi_c^+ K^-##. Each peak in the figure is a particle never seen before, and the significances of those peaks are about 20 sigma (10 sigma for the 5th one). A broad 6th state might hide around...

Homework Statement A beam of doubly ionized particles (i.e., twice the elementary charge) is accelerated across a potential difference of 2000 V in a mass spectrometer. They are then passed perpendicularly through a magnetic field of 0.085 T resulting in a radius of curvature 12.5 cm. Calculate...

I was thaught you can create a sinusoidal wave by making a source oscillate with simple harmonic motion in a medium, such as moving one end of a rope up and down to create a periodic transverse wave. For transverse waves, it is easy to see that every particle in the rope moves up and down with...

if i connect an electric current of 30 volts to argon gas to transform it to plasma, what is the average kinetic energy of the argon particles in that plasma?