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2
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1answer
74 views

Estimate the difference between two sets of atoms

I've been working on amorphous structures derived from a crystalline one (using MD) containing $N$ atoms. I want to prove that these structures are different and to quantify their "differentness". One ...
0
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2answers
181 views

Why is electron presented in books, pictures as a sphere?

Why is electron presented in books, pictures as a sphere, when in fact it's not?
1
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2answers
178 views

Does the unpredictability in the “micro world” means that everything is if we can look at it close enough imperfect?

Does the unpredictability in the "micro world" means that everything is if we can look at it close enough imperfect? I mean, there is a saying "You will never stand in the same river again" or ...
0
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2answers
115 views

Can energy be defined as the most fundamental particle which exists in different forms as protons, electrons etc

What we see all the different forms of matter around is just a form of energy. Why can't this energy be the most fundamental particle. Given dust can turn into a star and then emit all sorts of ...
2
votes
2answers
4k views

Frequency of an Electron

My question is very simple. If frequency is defined as the cylces per unit time, Then what is meant by "Frequency of an Electron" ? If the rotation of electron around a nucleus is considered then, ...
2
votes
2answers
172 views

Is there a map of the particles in outer space?

Since outer space is not quite a vacuum, and the distribution of various heavenly bodies is locally inhomogeneous, it seems reasonable to expect that the density and variety of particles ...
2
votes
2answers
191 views

Why does the amplitude of a ripple tells us that it is a particle?

The quote below is from Matt Strassler's blog: a particle is a ripple with many crests and troughs; its amplitude, relative to its overall length, is what tells you that it is a single ...
1
vote
1answer
147 views

Lifetimes of stable particles

What are possible lifetimes of up/down quarks, electronic/muonic/tau neutrinos, photon, gluon? I understand they are said to be stable, but, as I saw on wikipedia, the lower bound for the "stable" ...
0
votes
1answer
150 views

Is the idea of dividing the universe into particles anything more than an untrue convenience? [closed]

In theory, we speak of a particle as having properties. In reality, the measurement of any property is just an interaction between the target to be measured, and the measuring apparatus, where the ...
1
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3answers
259 views

Do particle pairs avoid each other? Please end my musings

Can you explain what happens when a particle and its antiparticle are created. Do they whiz away from each other at the speed of light or what? I suppose that they don't because otherwise they would ...
2
votes
1answer
140 views

Can you tell if a particle is in superposition?

This may be an easy answer for anybody. Is it possible to detect if a particle A is still in a superposition via the sending a group of particles B through a box containing particle A?
3
votes
2answers
161 views

How can Sub-Atomic Particles be Visualized?

Can you see or accurately visualise sub atomic particles or are they known only by maths and/or inference?
4
votes
1answer
174 views

Temporal part of Quantum Wavefunction

I was hoping that someone could give me the more fundamental reason that we take as the temporal part of a quantum wavefunction the function $e^{-i\omega t}$ and not $e^{+i\omega t}$? Clearly ...
2
votes
3answers
9k views

How to deduce E=(3/2)kT?

It says in my course notes that a particle has so-called "kinetic energy" $E=\frac{3}{2}kT=\frac{1}{2}mv^²$ Where does this formula come from? What is k?
8
votes
6answers
858 views

What is the meaning of the word “particle” in particle physics?

I want to use Matt Strassler's definition of the word "particle" as a specific example: Matt Strassler writes: (1) "...all the elementary “particles” (i.e. quanta) of nature are quanta of waves ...
0
votes
3answers
184 views

Center Of Mass Troubles

I understand the concept of Center Of Mass(com), but I am having a difficult time interpreting the equation of the simplified case of one-dimension. The book I am reading defines the position of the ...
3
votes
2answers
337 views

Particles vs Waves

As I remember long ago, in my physics classes, I always had a great trouble understanding the concept of waves. Our professor used to explain, as if everything in this world is made up of waves. ...
2
votes
1answer
138 views

$sss$ decay and violation of strangeness

Why can the hyperon $\Omega^{-}$ not decay by strong interaction? It seems that strangeness must be violated, but why is it the only way?
6
votes
1answer
258 views

Why doesn't my particle simulation end in a flat disc?

I've made a 3d particle simulator where particles are attracted to each other by the inverse of the square radius. The purpose of my experiment is to see if this alone would create a flat disk (like ...
3
votes
2answers
176 views

Understanding a Physics Paper on Quantum Teleportation of Continuous variables

The paper I am trying to understand is here: http://pra.aps.org/abstract/PRA/v49/i2/p1473_1 The paper describes the quantum teleportation protocol in a general case with continuous dynamical ...
0
votes
1answer
147 views

Would synchronized dancing be a good way to describe entangled atoms to a laymen?

I was talking my professor about entanglement swapping between light and matter and it is briefly described here: You start out with a crystal capable of doing parametric down conversion of incoming ...
1
vote
1answer
434 views

Definition of elementary particle [duplicate]

Possible Duplicate: Why are atoms particles? According to wikipedia an elementary particle or fundamental particle is a particle not known to have substructure. Moreover, I've learned ...
1
vote
1answer
348 views

What was the first discovery of the delta baryon $\Delta^{++}$?

The delta baryons (also called delta resonances) are a family of subatomic hadron particles which have the symbols $\Delta^{++}$, $\Delta^{+}$, $\Delta^{0}$, and $\Delta^{−}$ and electric charges +2, ...
1
vote
2answers
204 views

Why are atoms particles?

The Oxford English Dictionary definition of particle is as follows: "A component of the physical world smaller than the atom." I read an article in NewScientist and it said "...all particles from ...
5
votes
5answers
700 views

The observation of a non-SM resonance at 38 MeV

Was reported here. Of course if this is real it is very exciting. It leads me to the question: given that it took so long to find this resonance at a meager 38 MeV, is it possible that all SUSY ...
2
votes
0answers
831 views

Why is it that protons and electrons have exactly the same but opposite charge? [duplicate]

Possible Duplicate: Why do electron and proton have the same but opposite electric charge? Doesn't it seem very curious that one is an elementary particle and the other a subatomic particle ...
0
votes
2answers
1k views

Mechanism of Pair Production and Annihilation of Matter

Pair production is where an energetic photon on its interaction with strong electric field surrounding a nucleus produces electron-positron pair. Annihilation of matter is its converse where an ...
2
votes
1answer
78 views

Is Joule heating only between charged particles?

The Wikipedia page for Joule heating explains "It is now known that Joule heating is caused by interactions between the moving particles that form the current (usually, but not always, electrons) and ...
2
votes
5answers
175 views

Photoelectric effect without light rays

For electromagnetic waves we have the photon association, one imagines light as particles "flying around". What is the analogy for a constant electrical field, one which doesn't change in time ...
3
votes
3answers
523 views

Existence of creation and annihilation operators

In a multiple particle Hilbert space (any space of any multi-particle system), is it sufficient to define creation and annihilation operators by their action (e.g. mapping an n-particle state to an ...
2
votes
2answers
208 views

Very basic question on spin

Can anyone give a simple explanation for what the fractions and integers mean in particle physics when describing spin? I've seen on another forum (the naked scientist) that it should not be thought ...
2
votes
2answers
301 views

Some very basic questions on the Higgs Boson

What exactly is a boson? Is the Higgs boson the cause of gravity or a result of it? Does the collision of particles at the LHC create a gravity field or waves or somehow interact with the gravity ...
7
votes
3answers
279 views

Is particle number a problem for formulating statistical physics in a mathematically rigorous manner?

Quantities like the chemical potential can be expressed as something like $$\mu=-T\left(\tfrac{\partial S}{\partial N}\right)_{E,V}.$$ Now the entropy is the log some volume, which depends on the ...
2
votes
3answers
808 views

What entities create a gravitational field?

It is well known that masses create a gravitational field. Photons are affected by gravitation, but do they generate a gravitational field as well? What about the other gauge bosons? Do gravitons ...
1
vote
1answer
84 views

The Large Hadron Collider produce material residues?

In the LHC particles are accelerated until they collide, producing energy and this make new particles. My question is what happened after this. What happened to new particles and to old particles ...
0
votes
3answers
434 views

Can every particle be regarded as being a combination of Black holes and White holes?

Can the statement be regarded as true? That every particle, or element in the universe can be regarded as a combination of black hole and white hole in variable proportion.
1
vote
4answers
909 views

How can/does calculus describe the movement of a particle?

I was talking to Roger Penrose about calculus in the appendix in his book Cycles Of Time and he said I'd need a good understanding of calculus if I wanted to read his book in great depth. He said I ...
4
votes
2answers
261 views

Higgs boson and quasiparticles

Do we know exactly the difference between particles and quasiparticles? Is Higgs boson a particle or a quasiparticle? I ask this because if I understood well, Higgs boson created by a spontaneaous ...
1
vote
2answers
267 views

How can particles being closed strings in String Theory create solidity in objects?

I understand how particles with certain masses can form to make atoms, which create solidity in objects due to Pauli's Exclusion Principle and what have you. These particles actually have mass and to ...
3
votes
0answers
216 views

what interactions would take place between a free proton and a dipolariton?

What interactions can be expected to take place between a free proton and a dipolariton, (a) at high energies and (b) at lower energies? A dipolariton is a bosonic quasi-particle mentioned in a ...
2
votes
1answer
212 views

A question regarding particle trajectories in the symplectic manifold formalism

How to solve a free particle on a 2-sphere using symplectic manifold formalism of classical mechanics ? Is there a way to get coriolis effect directly, without going into Newton mechanics? And is ...
1
vote
4answers
695 views

Questions on wave-particle duality

Wave-particle duality states that a particle has both wave properties and particle properties when one is not observing it. 1) What is an observer? Need it be anything living or can other particles ...
2
votes
2answers
277 views

How the nucleon structure has been identified experimentally?

It is known that nucleons (proton, neutron) are composed of partons (quarks, etc.). How was this identified experimentally? In particular, how it has been identified that nucleons comprise of more ...
17
votes
3answers
1k views

Are elementary particles actually more elementary than quasiparticles?

Quarks and leptons are considered elementary particles, while phonons, holes, and solitons are quasiparticles. In light of emergent phenomena, such as fractionally charged particles in fractional ...
5
votes
2answers
787 views

Do particles and anti-particles attract each other?

Do particles and anti-particles attract each other? From the very basic understanding that they are created out of nothing mutually and collide to annihilate each other seems to indicate this happens ...
1
vote
1answer
199 views

Stability of neutron [duplicate]

Possible Duplicate: How come neutrons in a nucleus don't decay? It is known that free neutron decays in 15 minutes on average. Why is it much more stable when "placed" in nuclei? Edit: ...
8
votes
1answer
530 views

why is there no ninth gluon?

A teacher of mine told me once that there were no ninth gluon because such a one should be white and interact infinitely far, and no one has been observed. Is there also a theoretical reason?
1
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0answers
32 views

GUT predictions for charm mass?

Most GUT models have some relationship between down-type quarks and leptons, that more or less agree with the observed values after running the renormalization equations. But, what about up-type ...
0
votes
2answers
182 views

Speed Distribution of The Particles

I want to know the distribution of the particles's speed. The particles what I mean are nucleons and electrons of element. Consume there is 1kg of iron on room temperature and it's shape is sphere. ...
3
votes
3answers
1k views

What is lepton number?

What exactly is a lepton number of a particle? With the charge (eg proton is just 1, not the exact charge), I can understand because it's a physical property, put a particle with charge + next to ...