/sci/ - Science & Math

[Anonymous No.11825830]

In a theoretical scenario where it's absolute 0 degrees kelvin, would these little buggers still move?

If yes: why? What is giving them the energy?

[Anonymous No.11826657]

>>11825830
in thermodynamics / statistical mechanics, you define temperature relative to a reference frame, typically the center of mass frame. a system of particles with 0 temperature in the rest frame still has all particles in motion due to 0 point energy, which you could rationalize in terms of heisenberg uncertainty on position/momentum.

[El Arcón No.11826927]

The theoretical scenario which says those guys exist says that absolute zero is not a physical temperature.

[Anonymous No.11826978]

>>11826927
another retard thread by psycho pseudman

[Anonymous No.11826990]

>if we violate an axiom of physics does physics make sense?
Gee what do you think

[Anonymous No.11827316]

>>11825830
in a theoretical scenario it is impossible to reach 0 kelvin (not "degrees kelvin"). It violates the second law of thermodynamics. So your question is absolutely pointless.

[Anonymous No.11827408]

>>11827316
that’s absolutely not true. in fact, a population inversion technically has negative temperature

[El Arcón No.11827454]

>another retard thread

[Anonymous No.11828253]

>>11825830
The bosonic particles would form a Bose-Einstein condensate (they can all occupy the ground state). The fermions cannot all be in the ground state (Pauli exclusion principle), so the system would always have non-zero energy. It would be from the exclusion principle. Think about it like an internal energy for the fluids in compact objects like white dwarfs or neutron stars.

[Anonymous No.11828358]

>>11825830
If it's 0 degrees kelvin there are no photons or massive bosons like the higgs. All of these particles are excitations of a field. If there is no temperature there are no particles, unless there is a conserved number density.

The only conserved number density in the Standard Model is baryon number minus lepton number. So at zero temperature either you have no particles at all, or if fix there to be some baryons then the quarks within the baryons would necessarily be "moving" since they are confined.

[Anonymous No.11828702]

Wait so how was 0 Kelvin even established? What's the basis for such an arbitrary temperature? Is it largely bullshit?

Retard here btw

[Anonymous No.11828707]

>>11828358
But i thought the molecules were made up of electrons + neutron/potrons/whatever, which in turn are made up by these quantum thingies. It's not like the object would seize to exist only because it gets really cold?

Have in mind, i'm ultra noob at standard model

[Anonymous No.11828740]

>>11828707
he is not saying that matter goes away when it is at absolute 0. matter made of fermions, like electrons and quarks (i.e. what matter is normally made of), is perfectly stable at absolute 0.

[Anonymous No.11828761]

>>11828707
Yes, things like photons would cease to exist because it gets really cold. Particles like photons as well as electrons and quarks are oscillations of quantum fields. When the temperature gets lower these fields don't want to oscillate as much so the particles go away.

But in the case of electrons, neutrons, protons there are particle number conservation laws that can make it so those particles can't go away. So if you have either an electron or proton alone in the universe and cooled it down they would still be there. But there are extremely rare processes in the standard model called spheralons that can make it so if you have an electron and proton together and cool it down, they can go away.

[Anonymous No.11829895]

>>11828761
>But there are extremely rare processes in the standard model called spheralons that can make it so if you have an electron and proton together and cool it down, they can go away.
sphalerons are extremely high energy phenomena. the probability of a sphaleron being created at even LHC temperatures is very close to 0. asking for a sphaleron to happen randomly/spontaneously in a solid at absolute 0 might be even lower probability than having a black hole form randomly/spontaneously (and the black hole could then decay into bosons) in the same scenario. they are both going to be ridiculously rare

[Anonymous No.11830428]

>>11829895
>asking for a sphaleron to happen randomly/spontaneously in a solid at absolute 0
Nothing is happening at absolute 0. When you are at absolute zero you are in the ground state, or if you have a conserved charge it can also make sense to talk about the lowest energy state with a given value of the charge (since it commutes with the Hamiltonian).

The fact that there are spheralons means that states with definite baryon number and lepton number separately are not eigenstates of the Hamiltonian. The minimum energy state with equal baryon and lepton number is the vacuum. Of course if you start from real matter and somehow try to cool it down because spheralons events are so rare the system won't come to the true equilibrium, but in the case it is not in thermodynamic equilibrium it doesn't make sense to talk about temperature. I am talking about what absolute zero means in the standard model.

[Anonymous No.11830509]

>>11830428
well your interpretation of the physics is wrong. if you are thinking about normal matter made of baryons and fermions in the standard model at absolute 0, then it is stable, unless you suppose high energy fluctuations occur (which is possible since quantum fluctuations always happen probabilistically). my point is that if you think sphalerons or other high energy excitations can occur even in a 0 temperature state, then if you incorporate gravity into your considerations too, then black holes can occur as fluctuations too. and their probability may or may not be higher than sphalerons depending on your theory of quantum gravity. since sphalerons are super high energy and have just as much theoretical uncertainty in their parameters as quantum gravity

[Anonymous No.11830517]

>>11830509
I'm talking about an abstract theory where the Standard model is all there is and there is no gravity. Spheralons can not occur at a zero temperature state, you are not understanding what it means to be in thermal equilibrium.

[Anonymous No.11830528]

>>11830517
Actually maybe a better way to put it is that spheralons are always occuring at a zero temperature state (or any other temperature) since they determine what it means to be in equilibrium. In any case my point is that if you are not in the vacuum at absolute zero you haven't fully equilibriated yet.

[Anonymous No.11830690]

>>11830528
>In any case my point is that if you are not in the vacuum at absolute zero you haven't fully equilibriated yet.
sure. then any particles which are not absolutely, without exception, do not qualify as “equilibrium”. you are right that even in the standard model, there exist processes which say even normal matter does not count as “equillibrium” due to sphalerons which can decay normal matter. i am saying that that is true, but that level of nitpicking is such a fine detail that at that point one must consider the nitpicks of quantum gravity since they well be more relevant in the real world than sphalerons are

[Anonymous No.11830707]

>>11830690
okay i fucked this post up but you get my point. when you argue that normal fermionic matter is not the ground state then quantum gravity enters even before sphalerons or whatever exotic SM shit you can pull out of your hat

[Anonymous No.11830766]

>>11830707
Yeah fair enough I see your point, I'm a theorist first and a physicist second :)

[Anonymous No.11830940]

>>11830766
cool. i appreciate your post though. pointing out that the SM predicts B-L number violation even if you ignore gravity is a good point to make. it shows that there are high-energy processes that challenge the ordinary view of the stability of matter, even without thinking about “new physics”, it happens even in the SM. and that is worth remembering

[Anonymous No.11831578]

>>11826990
t. never made it past high-school physics

[Anonymous No.11832045]

>>11831578
t. Am an actual physicist you tard

[Anonymous No.11832087]

>>11832045
So am I. Also, I've won two Nobel prizes. What now, bitch?

[Anonymous No.11832315]

>>11832087
Do you think anyone would fall for that?

[Anonymous No.11832326]

>>11828253
>bosonic particles
Just say boson.

[Anonymous No.11832377]

>>11832326
no. many non-bosons have an even spin, from mesons up to whole molecules
"just say boson" is as stupid as calling any red vehicle a firetruck

[Anonymous No.11832404]

Physics has become a joke, and I point at this thread as evidence.

[Anonymous No.11832415]

>>11832404
have sex

[Anonymous No.11834455]

>>11832377
those are bosons anon...

[Anonymous No.11834976]

Helium stays liquid all the way down to 0 K.

[Anonymous No.11835015]

>>11825830
>absolute 0 degrees kelvin
Positive or negative 0K? :^)