The pauli-exclusion-principle tag has no wiki summary.
2
votes
1answer
32 views
Falling through the ground [duplicate]
I do not know much about physics but I know that according to Newtons third law of motion when we walk we are pushing the ground down but the ground is pushing us up. What force is making the ground ...
2
votes
1answer
50 views
Possible states for two electrons in the helium atom
Consider the helium atom with two electrons, but ignore coupling of angular momenta, relativistic effects, etc.
The spin state of the system is a combination of the triplet states and the singlet ...
1
vote
1answer
90 views
Quantum computing and Pauli exclusion principle?
Ok so I saw this video by Brian Cox where he explains how no 2 particles can have same energy level.
Later I watched video "Was Brian Cox wrong?". Where they explained that he (probably on purpose) ...
4
votes
2answers
195 views
What prevents bosons from occupying the same location?
The Pauli exclusion principle states that no two fermions can share identical quantum states. Bosons, one the other hand, face no such prohibition. This allows multiple bosons to essentially occupy ...
1
vote
0answers
26 views
Is there anything to prevent paired-up neutrons from a complete overlap
The reason "neutrons don't overlap", as DarenW explained it, has to do with intricate forces at play that take into account the spins, iso-spins and symmetry of the wavefunctions.
However, assume I ...
0
votes
4answers
179 views
Why are electrons consider waves?
I know the wave nature of electrons was evoked to explain why atoms are stable but I thought waves could be put in the same state like photons yet electrons can not exist in the same state.
1
vote
3answers
129 views
I don't understand the relationship between electron indistinguishability and the Pauli exclusion principle
I know I'm wrong but this is my line of thought: If electrons are indistinguishable, then why do we have an exclusion principle? If we have two electrons in an s orbital, the Pauli exclusion principle ...
2
votes
1answer
78 views
Spin and Parity of $^{17}_8 O$ excited states
$^{17}_8 O$ quoted here has a spin of 5/2 and parity of +1 for the ground state, I agree with this, the unpaired neutron is in the $1d_{1/2}$ state so l = 2, spin = 5/2.
Now I want to figure out the ...
1
vote
2answers
317 views
Is the Pauli exclusion principle as Brian Cox described it? [duplicate]
Possible Duplicate:
Does the Pauli exclusion principle instantaneously affect distant electrons?
If this rule works, could you not set up an experiment to test the theory (as described by ...
13
votes
2answers
357 views
Can bosons that are composed of several fermions occupy the same state?
It is generally assumed that there is no limit on how many bosons are allowed to occupy the same quantum mechanical state. However, almost every boson encountered in every-day physics is not a ...
6
votes
1answer
282 views
Is Pauli-repulsion a “force” that is completely separate from the 4 fundamental forces?
You can have two electrons that experience each other's force by the exchange of photons (i.e. the electromagnetic force). Yet if you compress them really strongly, the electromagnetic interaction ...
2
votes
1answer
151 views
A question about Pauli’s exclusion principle and electron orbital
According to Pauli’s exclusion principle, $s$ orbital contains at most two electrons with the opposite spin(up and down). Why can't $s$ orbital contain a third electron whose state is the linear ...
10
votes
2answers
156 views
Capactiy of an orbtial to hold muons and electrons
In a normal atom, there is a limit of 2 electrons per obital due to the Pauli-Exclusion principle. I have seen people talking about replacing an electron with a muon, but since muons and electrons are ...
0
votes
1answer
174 views
Why do electrons make a Fermi sphere?
In Sommerfeld theory for metals, after determining all of the possible levels for a single electron, one says that we build up a state for a system with $N$ electrons by filling up those levels, ...
1
vote
2answers
166 views
Why Pauli exclusion instead of electrons canceling out?
To quote Wikipedia,
The Pauli exclusion principle is the quantum mechanical principle that no two identical fermions (particles with half-integer spin) may occupy the same quantum state ...
0
votes
0answers
29 views
Can neutrinos be the dark matter [duplicate]
Possible Duplicate:
How do we know Dark Matter isn't simply Neutrinos?
If there are primardian neutrinos and since they have some mass however low, could neutrinos form the dark matter ...
0
votes
1answer
105 views
In a neutron star - what force keeps the neutrons from getting closer and closer? [duplicate]
Possible Duplicate:
Why do neutrons repel each other?
What I mean is that the neutrons are attracted to one another via gravity, so what force keeps them from collapsing to form a "neutron ...
1
vote
1answer
118 views
Impervious nature of solid matter due to quantum degeneracy pressure
On Wikipedia the following statement is made without reference:
Freeman Dyson showed that the imperviousness of solid matter is due to
quantum degeneracy pressure rather than electrostatic ...
1
vote
1answer
162 views
Why are do neutral atoms shrink as their valence shells approach 8 electrons?
Why do neutral, unbonded atoms shrink in size as they approach having 8 electrons in their valence shells? A good example is elements 3 through 10 in this table, that is, lithium (1 valence electron) ...
1
vote
2answers
647 views
Why can't two or more objects exist at the same place at the same time?
Two objects with half spin would consist of the elementary particles (i.e. quarks, fermions etc.) which are waves. Therefore all objects consist of several waves. Waves can exist at the same place at ...
6
votes
1answer
358 views
Degeneracy Pressure, What is it?
There has been numerous question, some violent even in physics@SE regarding PEP and EM forces.
But what baffles me is what is degeneracy pressure? I know there are 4 fundamental forces- EM, gravity, ...
3
votes
1answer
139 views
Do mass and the Pauli exclusion principle conspire to make light fermions take up more space?
The wavelength of light fermions is longer. Wouldn't this cause them to take up 'more space' so that they didn't overlap according to the Pauli exclusion principle? Am I totally misunderstanding ...
14
votes
10answers
6k views
Does the Pauli exclusion principle instantaneously affect distant electrons?
According to Brian Cox in his A night with the Stars lecture$^1$, the Pauli exclusion principle means that no electron in the universe can have the same energy state as any other electron in the ...
4
votes
5answers
2k views
If the earth has gravity, why don't we all collapse to the center?
I'm sorry if the answer is obvious for you guys, but why don't we all (including buildings, road, people, the ground) collapse to the center of the earth because of gravity? Is it because we have ...
7
votes
4answers
2k views
What is the cause of the normal force?
I've been wondering, what causes the normal force to exist?
In class the teacher never actually explains it, he just says "It has to be there because something has to counter gravity." While I ...
6
votes
2answers
971 views
What causes the Pauli exclusion principle (and why does spin 1/2 = fermion)?
It seems to be related to exchange interaction, but I can't penetrate the Wikipedia article. What has the Pauli exclusion principle to do with indistinguishability?
40
votes
10answers
3k views
How can I stand on the ground? EM or/and Pauli?
There is this famous example about the order difference between gravitational force and EM force. All the gravitational force of Earth is just countered by the electromagnetic force between the ...
10
votes
7answers
2k views
Why do neutrons repel each other?
I can understand why 2 protons will repel each other, because they're both positive. But there isn't a neutral charge is there? So why do neutrons repel (do they even or Have I been misinformed?)
...
