@PM2Ring oh nice, i was just thinking of our conversation about simulating sub-quark phenomena, and i think you said that sub-quark energy density is similar to that on a similar timescale from the commencement of the big bang. something along those lines. it made me wonder if those simulations could be used to yield insight into that epoch of the bigbang?

hmm or vice versa potentially

@antimony Particle physics has been a vital component of astrophysics ever sinve it was realised that stars are powered by nuclear fusion. For some historical info, see en.wikipedia.org/wiki/Stellar_nucleosynthesis en.wikipedia.org/wiki/B2FH_paper en.wikipedia.org/wiki/Alpher%E2%80%93Bethe%E2%80%93Gamow_paper

en.wikipedia.org/wiki/… has details of the processes in the early universe. Much of that information is derived from particle physics theory & experiments. And spectroscopic observations of the cosmic abundances of the elements provide evidence that our theories of primordial nucleosynthesis are reasonably good, although there are some minor discrepancies, eg in the abundance of lithium.

funny, just gave a presentation on B2FH today for a class

However, it's not easy to do particle experiments at extremely high energies. The biggest particle collider is currently the LHC. Sure, a bigger collider could investigate higher energies, but we might need a collider that's much bigger than the LHC before we discover anything significant. It would be difficult to get funds for a 1000 km collider if we expect that it won't see anything new. ;)

@SirCumference Cool! TIL that Margaret Burbidge died only a couple of years ago. en.wikipedia.org/wiki/Margaret_Burbidge

hahah true

oh nice, that is good info :)

which epoch was the one we were discussing?

hmm i think it must have been planck epoch

I commited my usual mistake of not writing down where a specific theorem is written and now I forget

In special relativity, is the rest energy of a particle always smaller than the energy of that particle in any other frame?

I think this is true because taking a look at the relativistic energy-momentum equation, the mass energy term is lorentz invariant, i.e. won't change when we change frames. And, the momentum term is always positive since it is initially squared. Thus, in a frame in which your object is not at rest, the energy will be the rest energy + (an always positive) momentum term

sorry i used rest energy and mass energy interchangably ^

Yes, the total energy of a mass m is given by E² = p²c² + m²c⁴ so the minimum value for E is when p = 0 i.e. the rest frame of the mass.

Excellent!

@Slereah I'm kind of compulsive about that

I have to write where every additionale remark/theorem is written but I do that on pieces of paper (so I don't make my notes messy) or on a specific agenda

Hi

@Feynman_00 can u help me with a theoretical question

Uh? I don't think I'm a good choice :P What do you need?

Does anyone know of some resources to get a basic understanding of what role the Heisenberg Group plays in quantum. I have just learned the definition of the group itself from Abstract Algebra, and am finding it hard to understand what the point of it is.

the canonical commutation relation obeys the same algebra as the Heisenberg group

@SillyGoose maybe Peter Woit's book, he should have made the pdf accesible online