When a gas atom gains kinetic energy by interacting with a hot solid. Is it that the solid's atoms/molecules are mechanically moving alot? Or is it the charges within the solid is moving alot, which then imparts kinetic energy to the gas?

Then again, I suppose on that level, what is a moving atom/molecule except a moving charge....

I'm not sure how helpful that thought is for this application though...

@Slereah his email list is about a hundred people long

I think he took names from various GR conferences

@RyanUnger maybe he found your physics criticism sympatico :p

@antimony In a solid the atoms/molecules vibrate around their equilibrium position so they have vibrational energy. When a gas molecule hits the surface it can transfer its KE to the solid and increase the energy of the vibrations, or the vibrational energy can be transferred to the gas molecule and increase its KE.

@RewCie ?

awk is a text processing tool.

LSD is creativity enhancing tool

Hi All...

Hello @JohnRennie after long nice to see you.

Hello @ACuriousMind

Ahh lovely thanks @JohnRennie , so they are mechanically vibrating around the equilibrium, which is governed by the electric forces binding them to their surrounding atoms/molecules?

@antimony Yes. The energy of the vibration is the way heat is stored in the solid, so increasingly the vibrational energy makes the solid hotter and decraesing it makes the solid colder.

lovely thanks @JohnRennie and when eg. a solid vaporises is it because the vibrational energy overcomes the electric force binding them to surrounding atoms/molecules?

@antimony Yes, exactly. As you increase the temperature the amplitude of the vibration increases, and eventually the atoms just shake themselves loose.

incredible thanks @JohnRennie, one thing i puzzle over is how this vibration leads to emission in solids. since if this mechanical vibration creates an oscillation in charge density which creates the emission.

yet it seems incredible to think the atoms/molecules are mechanically vibrating at eg. 30 THz at room temperature (say 290K). So is there some mechanism by which the charge densities are oscillating at much higher frequency than the vibration frequency?

or can they actually vibrate at 30 THz? If I understand what you taught me previously, in gases such an emission is a quantum photon emission from a state transition. So the vibration doesn't need to be at 30 THz. but in solids it really puzzles me

is it because there are so many adjacent charges in a solid, that the effective acceleration of charges relative to eachother is enough to effectively "upconvert" the lower frequency vibrations into higher frequency charge density oscillations?

i suppose its not inconceivable there could be a nonlinearity between different modes, ie. vibration vs charge oscillation....

Black body radiation is related to oscillations in the electron density rather than directly to the oscillations of the atoms (i.e. oscillations of the nuclei since the nucleus makes up 99.99% of the mass of the atoms).

ahh i see

The electrons are much lighter than the nuclei so they oscillate at a much higher frequency.

ohh!

lovely

makes sense :)

is it ok to think of it in a very very simple way like an harmonic oscillator. since a lower mass will have a higher frequency?

@antimony well it's a whole array of coupled simple harmonic oscillators, but basically yes you can think of it that way.

one thing which I realise I have no clue about: why is the moduli space of a supersymmetric gauge theory equivalent to the space of single-trace scalar operator VEVs?

is this something obvious?

@NiharKarve I'm not 100% sure what you mean but vacua are classified by scalar values because non-scalar values would contradict the Lorentz invariance of the vacuum

yes, of course

but why single-trace?

and why all such VEVs

the prototypical example I'm thinking of here is SQCD, where the moduli space can be parameterised by mesons and two baryons

ah wait I think it's shown in arxiv.org/abs/hep-th/9506098

lovely, thanks alot @JohnRennie everytime you teach me so much great stuff!! :)

I recognized a weird parallelism. Between quantum mechanics in physics and version control systems in the IT

In both: we have a known initial state, then various indetermined states, and then an again well-known result

wave function is like a set of development branches

Probably IT would be much more hard with $\aleph_1$ branches.

@ACuriousMind I think, exactly this type of people should be cared very nicely, if the site goals are important for us.

Downvoted, closed, deleted questions are likely not very attractive for them, even if the down-close-del votes perfectly conform everything.

@Slereah lol