Is it possible to change the spin of a proton?

[Hami Hashmi]

Because the proton is not an elementary particle so I was wondering if it was possible to change the magnitude of the spin.

[swansont]

No. Just the spin projection (spin up vs. spin down)

There is only one way for the quarks to combine and have it be a proton. There are two up quarks. They have to be anti-aligned in the ground state because of the Pauli exclusion principle 

[Hami Hashmi]

30 minutes ago, swansont said:

No. Just the spin projection (spin up vs. spin down)

There is only one way for the quarks to combine and have it be a proton. There are two up quarks. They have to be anti-aligned in the ground state because of the Pauli exclusion principle 

Ok but then is it possible to change the magnitude of the spin of a electron and up quark (i know this would not be stable but for the limited time that it is would it be possible?)

Edited August 26, 2018 by Hami Hashmi

[swansont]

51 minutes ago, Hami Hashmi said:

Ok but then is it possible to change the magnitude of the spin of a electron and up quark (i know this would not be stable but for the limited time that it is would it be possible?)

No, spin is an intrinsic property, and is quantized. These are spin 1/2 particles.

[Hami Hashmi]

Ok thanks. So the resulting particle will have a spin of 1/2?

Edited August 26, 2018 by Hami Hashmi

[swansont]

1 hour ago, Hami Hashmi said:

Ok thanks. So the resulting particle will have a spin of 1/2?

You can't make anything from an electron and an up quark.

[Hami Hashmi]

Ok fine but for the sub-microsecond that they are together what will be the spin then?

[Markus Hanke]

7 hours ago, Hami Hashmi said:

Ok fine but for the sub-microsecond that they are together what will be the spin then?

In a general scenario where you combine two spin-½ particles, the overall system would have either total spin 0, or total spin 1, with (I believe) equal probability.

[Hami Hashmi]

Thanks.

[Hami Hashmi]

The only reason why i was wondering is because it is possible to change the angular momentum of a singularity (which is a point) so I thought it would be possible to do the same with two point particles using magnetism.

[Markus Hanke]

The angular momentum of a black hole is a property of the entire spacetime, and not of the singularity (which only arises in our models in the first place because we can‘t yet account for quantum effects). Furthermore, while spin can be considered a form of angular momentum, it is quite different from the one of macroscopic bodies.

[Hami Hashmi]

16 hours ago, Markus Hanke said:

The angular momentum of a black hole is a property of the entire spacetime, and not of the singularity (which only arises in our models in the first place because we can‘t yet account for quantum effects). Furthermore, while spin can be considered a form of angular momentum, it is quite different from the one of macroscopic bodies.

So you are saying that a singularity does not really exist?

[Hami Hashmi]

4 hours ago, Hami Hashmi said:

So you are saying that a singularity does not really exist?

And if it did, would my theory (post #10) be valid?

[Markus Hanke]

7 hours ago, Hami Hashmi said:

So you are saying that a singularity does not really exist?

Of course it does not physically exist - it‘s just a mathematical artefact of the fact that GR is a purely classical model, and hence cannot account for quantum effects.

[beecee]

10 hours ago, lucks_021 said:

A thing that I want to know, using this topic which comes to this subject, is:

If in a singularity, the time passes so slowly that for us (out of it) it would be infinite (since the singularity has infinite density) how can we observe the effects of the black hole angular momentum? (if you don't understand something, please ask me, my english isn't good)

 

On 10/22/2018 at 2:29 AM, Hami Hashmi said:

The only reason why i was wondering is because it is possible to change the angular momentum of a singularity (which is a point) so I thought it would be possible to do the same with two point particles using magnetism.

The mathematical singularity where GR fails us, involves infinite spacetime curvature and infinite density, and this is why cosmologists do not believe it exists. Although we have no actual empirical evidence of what happens inside a BH, GR does tell us that once the Schwarzchild radius of any given mass is reached, further collapse is compulsory. But at the quantum/Planck level GR fails us, so it is I believe reasonable to assume that the mass resides somewhere at that level, before the infinities are reached. At the same time once any matter crosses the EH, it undergoes increasing stress [elongation/spaghetification] from the tidal gravity effects and depending on the size of the BH, will be broken down into its most basic fundamental parts, on its way to or at the quantum/planck/Singularity level. I think I have that reasonably accurate, if not someone who knows better can correct.

[Hami Hashmi]

13 hours ago, beecee said:

 

The mathematical singularity where GR fails us, involves infinite spacetime curvature and infinite density, and this is why cosmologists do not believe it exists. Although we have no actual empirical evidence of what happens inside a BH, GR does tell us that once the Schwarzchild radius of any given mass is reached, further collapse is compulsory. But at the quantum/Planck level GR fails us, so it is I believe reasonable to assume that the mass resides somewhere at that level, before the infinities are reached. At the same time once any matter crosses the EH, it undergoes increasing stress [elongation/spaghetification] from the tidal gravity effects and depending on the size of the BH, will be broken down into its most basic fundamental parts, on its way to or at the quantum/planck/Singularity level. I think I have that reasonably accurate, if not someone who knows better can correct.

Ok thanks. But if a singularity did exist, would my theory (post #10) be valid?

[beecee]

1 hour ago, Hami Hashmi said:

Ok thanks. But if a singularity did exist, would my theory (post #10) be valid?

Someone with more expertise then me can handle that. 

[swansont]

!

Moderator Note

The tangent on black hole properties has been split

https://www.scienceforums.net/topic/116694-black-holes-split-from-is-it-possible-to-change-the-spin-of-a-proton/

 

 

[Strange]

12 hours ago, Hami Hashmi said:

Ok thanks. But if a singularity did exist, would my theory (post #10) be valid?

Are you asking if it is possible to change the spin of a (fundamental) particle like a proton? That has already been answered (no). 

So what is your question?

[Hami Hashmi]

10 hours ago, Strange said:

Are you asking if it is possible to change the spin of a (fundamental) particle like a proton? That has already been answered (no). 

So what is your question?

ok thanks that's what i wanted to know.

[Rajiv Naik]

On 24/10/2018 at 4:33 PM, Strange said:

Are you asking if it is possible to change the spin of a (fundamental) particle like a proton? That has already been answered (no). 

So what is your question?

not about total spin - which will remain 1/2 as per physics.

but if photon is absorbed by proton would not it change its spin state ?

[swansont]

5 hours ago, Rajiv Naik said:

not about total spin - which will remain 1/2 as per physics.

but if photon is absorbed by proton would not it change its spin state ?

Since a photon is spin 1, yes, the spin state can change. Depending on the details of the interaction.