# What would happen to pauli exclusion principle

1. Apr 26, 2008

### Bose

Pauli exclusion principle say that no two electrons can occupy the same state. But what would happen if we force them to occupy the same states?

2. Apr 26, 2008

### dst

No two electrons can occupy the same state. Therefore your two cows *AHEM* electrons don't exist.

3. Apr 26, 2008

### olgranpappy

The pauli exclusion principle ultimately comes from the fact that the total wavefunction for a system of electrons must be antisymmetric. So, for example, if I have two electrons (with coordinates r1 and r2, respectively) and two states $\phi$ and $$\chi$$ the the total wavefunction would be
$$\Psi_{\rm tot}(r_1,r_2)=\frac{1}{\sqrt{2}}\left(\phi(r1)\chi(r2)-\chi(r1)\phi(r2)\right)\;.$$

so now, you tell me... what happens if the electrons are in the same state (i.e., if $\phi=\chi$)

4. Apr 26, 2008

### reilly

Can't put two fermions in the same state, but you can come very close. That is, for 2 spin up electrons, one could be at x=1.0, and another at 1.000000000000000001. Of course the electrostatic repulsive force between the two would make the assemblage difficult.
Regards,
Reilly Atkinson

5. Apr 27, 2008

### peter0302

When electrons or other fermions are sucked into a black hole, are they converted to energy? Otherwise, how is the PEP not violated then by the singularity?

6. Apr 27, 2008

### Schrodinger's Dog

AFAIK there is no violation of PEP, let alone conservation of energy. The universe outside of the event horizon gains energy and the black hole loses it. Net gain/loss to the universe 0.

7. Apr 28, 2008

### peter0302

That doesn't answer the question. How does matter get packed into a single point in space without violating the PEP? The only thing I can conclude is everything that goes into the black hole gets abosrobed as energy and therefore is no longer a fermion.