The tag has no wiki summary.

learn more… | top users | synonyms

0
votes
0answers
34 views

Easy to use particle tracking software [on hold]

I'm a physics student and we have to do an experiment. We follow a microscopic sphere of diameter about 40$\mu m$ for 20 $sec$, in water. The sphere will travel a distance wich we have to measure in ...
0
votes
3answers
98 views

Can two electrons attract each other?

Due to electrostatic repulsion the two electrons will repel each other as they both possess similar charges, lets leave gravitational attractive force out of the picture my question is can there be ...
-2
votes
1answer
39 views

What is the acceleration of a charged particle in uniform electric field [closed]

I would guess its $kC/r^2$, just like the in the context of gravitation, as one arrives at the acceleration due to gravity $g = GM/r^2$; but I am not sure.
-1
votes
1answer
27 views

Similarity between particles and antiparticles

I was doing a past exam paper and there was this question: State the similarities between a particle and its antiparticle. The answer given was: Same mass and rest energy. I am not too bothered ...
1
vote
0answers
24 views

Deceleration of spherical particle in fluid

If I know the initial velocity of a particle entering a fluid, how can I calculate its deceleration over time ? What parameters would I need to know ? Viscosity of the fluid, weight of the particle ...
0
votes
3answers
96 views

The Higgs field vs the Higgs boson

As I see it the Higgs boson is the mediating particle of the Higgs field and get its own mass from the Higgs field. Isn´t this circular? I mean, for instance, an electron creates a radial electric ...
0
votes
0answers
47 views

How many quantum fields are there?

I'm just an aficionado, but my understanding is that in QFT, the photon is an excitation of the electromagnetic field, the electron is an excitation of the electron field, and so on. Is there a ...
3
votes
2answers
34 views

Is the only difference between two particles their location and momentum?

Maybe this would be better suited for philosphy.se, if so, then let me know and i'll move it, but this seemed like a reasonable place to start. Let's start with my motivations for asking such a ...
0
votes
0answers
20 views

Hot air particles

I have a question- albeit random one!. I recently visited a friends place who used a standard shovel from the shed as a tool for moving hot charcoals around a pizza oven. Unfortunately the shovel was ...
0
votes
1answer
42 views

is electromagnetic phenomena and particle behavior dependent on dark matter?

Dark matter permeates space and coalesce s in its own gravitational attraction. It neither absorbs or emits light or interacts well with baryonic matter. It deflects light on a path and is the sub ...
0
votes
1answer
22 views

How can silicon have a capacity of 8 electrons in the outer shell?

I was reading an article on how solar cells work in this website- http://science.howstuffworks.com/environmental/energy/solar-cell2.htm In that website I have a doubt in the first paragraph i.e.- ...
0
votes
0answers
46 views

Direct interaction theory

I got to know about a kind of theory or formulation of EM which doesn't have the idea of fields in it. In that theory I guess field isn't that which mediates the force between two charged particles. ...
0
votes
0answers
12 views

Interaction rates from cross sections in a thermalized gas

Consider a target particle embedded in a gas with a thermal distribution of velocities. If we know the cross section $\sigma$ for interactions between the target particle and a gas particle, how do we ...
0
votes
2answers
53 views

Is it possible to make an electromagnetic shield?

Is it possible to make an electromagnetic shield to protect something (or ourselves) against things like bullets, human attacks, metals thrown on us or simple dust particles to protect a spaceship ...
0
votes
2answers
88 views

Does a photon travel in all directions?

For example i am standing and a beam of light is passing in front of me. I am able to see that beam of light so does it mean that photons are travelling in all directions other than the photons which ...
0
votes
0answers
31 views

beta minus decay: expression for maximum electron energy

I'm having some trouble finding an expression for the maximum electron energy in beta minus decay. In the frame where the neutron is initially at rest, conservation of momentum reads: ...
1
vote
1answer
51 views

Alpha particle in vacuum

Does the alpha particle travel in vacuum for ever and ever or can it undergo some transformation eg two protons get separated or the neutron decays etc.?
0
votes
0answers
26 views

Energy transfer (Bohr's stopping formula vs. Bethe's)

I'm currently reading about Bohr and Bethe stopping, and has come across a thing I can't entirely figure out. In my book it states: "Bohr's formula gives a reasonable description of the energy loss ...
0
votes
1answer
28 views

How does an electron beam condenser work?

For example, a scanning electron microscope has multiple condensers that "focus" the beam into a smaller spot size. How does a condenser actually change the direction of electron flow in a non-uniform ...
1
vote
0answers
46 views

Is there a typology of different fundamental physical objects?

As I understand it (and of course, I may be wrong!).... In classical mechanics, all objects are basically the same in the sense that They are composed of atoms bunched together. These atoms occupy ...
0
votes
1answer
52 views

two mutually attracted particles in 1D space

I'm wondering - can two particles under attractive force ever come to full stop in 1D space? Or will they oscillate for an infinitely long time?
4
votes
1answer
64 views

Rejecting background in $B$-meson decay

I want to reconstruct the $B$ mass from the decay $$ B^0 \rightarrow K^{0*} \gamma \quad\text{ where }\quad K^{0*} \rightarrow K^{+} \pi^{-} $$ and the equivalent antiparticle decay. A key element in ...
4
votes
2answers
289 views

The concept of particle in QFT

I never learnt QFT and I apologize for my (probably) elementary question. Somebody told me that in QFT a particle is viewed as an irregularity in the field. On the other hand, in an article in ...
0
votes
0answers
38 views

What does the phrase 'muons are brought to rest' mean?

I have a physics question in a text sheet. I am currently doing work on relativity where calculations of rest frames and laboratory frames are being completed. The formula: $t(\text{laboratory frame}) ...
2
votes
3answers
167 views

Is simulating the entire universe possible?

Is it concievable that we may one day simulate the entire universe with every single particle, field and law of physics factored in? Can n number of particles (say the number of particles that make up ...
0
votes
1answer
57 views

Special Relativity - three body problem

I have a problem with solving three-body problem in special relativity. I know that in general this problem doesn't have good solution, but I have a specific case when it should be good answer. ...
1
vote
1answer
66 views

In Bohmian mechanics, how does the particle's position affect where a particle is detected?

In Bohmian mechanics / pilot wave theory / de Broglie–Bohm theory, my understanding is that a particle's trajectory evolves based on its wave function, and that the position that particle is detected ...
1
vote
2answers
138 views

How do particles interact in Bohmian mechanics / pilot wave theory / de Broglie–Bohm theory?

I've read that in the de Broglie–Bohm interpretation of QM, the particle directed by its wavefunction has a trajectory (meaning both position and velocity) and that these are the only properties ...
0
votes
2answers
2k views

What is a wave? What is a particle?

I am reading a David Bohm book on quantum theory. He says the idea that light is both a particle and a wave is incompatible: (1) we know light has particle-like properties through the photoelectric ...
1
vote
1answer
551 views

What happens when an atom absorb electron/photon?

I'll give you a scenario or two, and please tell me what will happen and that shall answer my question. Thanks in advance. Scenario 1: Will an atom absorb an electron with kinetic energy greater ...
1
vote
0answers
20 views

How to calculate D0->K+K- decay with QCD factorization?

I am studying the decay of D0->K+K- and I calculated the result of Branching Ratio by Naive QCD and I wrote all the equations for amplitude and branching Ration and Hamiltonian and... for this decay ...
13
votes
3answers
509 views

Wave/particle-duality as result of taking different limits of a QFT

There is an account on dualities in quantum field theories and string theories by Polchinski from last week http://arxiv.org/abs/1412.5704 At the end of page 4, he writes the wave/particle ...
0
votes
3answers
184 views

Why is every particle a sphere?

I was wondering why is everything in this universe, I mean atoms and well quarks and photons and what not some form of sphere. Is there any exploitation to the sphere being perfect and only thing for ...
0
votes
0answers
9 views

how to completely remove the charge from the glass bubble particles?

Do you have any idea on how to completely remove the charge from the glass bubble particles (25-32 micrometer diameter)? Thanks
1
vote
1answer
60 views

using a given wavefunction to find particle properties

Let's say we have a given wavefunction and we want to find a particle that will fulfill the properties for that wavefunction. How can we do that? Is it possible? I was thinking of using Schrodinger's ...
1
vote
1answer
32 views

How to induce charge in glass bubble particles ?

I am trying to induce charge ( + or - ) in the glass bubble particles ( manufacturer 3M 25-32 micrometer) . Can anyone tell me how to effectively charge them. I have tried placing these particles in a ...
0
votes
1answer
81 views

Can matter be annihilated to form kinetic energy

I don't know much about conversion of energy and all, but I had a simple question: Can the energy released by converting matter into energy be used to set other particles in motion (increase their ...
0
votes
0answers
17 views

Particle Velocity and Air Velocity

Is the any relationship (equation) between particle velocity and air velocity? Is it possible to determine the air velocity from particle velocity?
1
vote
3answers
83 views

How are the half life of particles mathematically related to the inverse square laws?

This video https://www.youtube.com/watch?v=K6i-qE8AigE&list=PL3B0924C6A0CB8B67 explains how forces are boson particles. It talks about the other non-force particles giving off and creating bosons, ...
0
votes
1answer
75 views

How to convert cc to bar?

In astronomy/astrophysics, medium density is often given in cc, particles per cubic centimeter. Also, the temperature of the medium is usually given, in Kelvins. For some materials the melting point ...
1
vote
3answers
573 views

New subatomic particles

In reference to the findings talked about here http://online.wsj.com/articles/two-new-subatomic-particles-found-using-large-hadron-collider-scientists-say-1416409980 and other similar articles ...
4
votes
2answers
165 views

What makes a one particle state?

I'm trying to understand free particle states in quantum field theory but I'm having trouble with one thing: what exactly defines a one particle state? For example, we can define a 'plane wave' as a ...
1
vote
3answers
235 views

Photons as fundamental particles

Is there any theory, current or debunked, that considers the photon to be a non elementary particle? That is to say, is the photon just the photon or is there possibly more to the photon than just ...
3
votes
2answers
57 views

Adding a tracer to the surface of a water droplet

I have a 2 mm water droplet generated by a syringe and falling down. I am using two perpendicular cameras to capture simultaneous frames from it. I need to track the droplet during the time and ...
1
vote
0answers
25 views

Where does the polarity of particles come from? [duplicate]

Going though current lessons, I can clearly see that some particles, electrons, are charged negatively and other, protons, are charged positively. Where does this polarity come from? Knowing that ...
5
votes
1answer
190 views

Is the particle reaction $π^- + p \to K^- + Σ^+$ possible?

I'm currently going over some undergraduate exams on particle physics and I'm having problems with a specific reaction, namely $$ \pi^- + p \to K^- + \Sigma^+ $$ which, in my opinion, is not allowed ...
3
votes
1answer
79 views

Non-deterministic particle system

This question is in the spirit of Norton's dome, an example of an apparently non-deterministic system in Newtonian mechanics. Under certain restrictions, the Picard–Lindelöf theorem guarantees the ...
0
votes
1answer
32 views

Help Understanding Gaussian Particle Distribution

I have a simple enough problem. I want to mathematically describe a Gaussian particle distribution of $N$ total particles with a spot size of 0.1 (sigma). I need a function that will tell me the ...
26
votes
4answers
7k views

What would happen if an accelerated particle collided with a person?

What would happen if an accelerated particle (like they create in the LHC) hit a person standing in its path? Would the person die? Would the particle rip a hole? Would the particle leave such a tiny ...