pines-demon's latest activity

Glad to see many of my votes made it to the list and happy to discover users I did not know. Happy new year to everybody.

It's been another incredible year spent on PF! Thanks to all contributing members for making it special! This year we're coming upon 25...

Hornbein For those who brew good coffee and add no sugar, stirring is almost entirely unnecessary.

Why do you put sugar in your coffee!

There is a whole discussion in coffee media if one should swirl or stir (but is mostly related to getting an homogeneous espresso and is...

That's also what the Caltech physics department thought in the late 1970's. They used the Berkeley Physics texts for the first year, but...

I think this fits more in your thread than in mine as I think most of the funny citations are exactly that. Funny (apocryphal or not)...

Try Fetter&Walecka or Coleman.

Look at this notes from Berkeley: https://bohr.physics.berkeley.edu/classes/221/1112/notes/timerev.pdf They do the usual time-reversal...

But this ##H## still seems like an operator what does ##\nabla_r^*## mean?

Please copy the Hamiltonian here to understand your question better.

For that your Hamiltonian has to be diagonal in ##q##. Also you are assuming properties of ##\Theta## if not I don't get how are you...

Sorry this gets confusing because we mix various stuff in second quantization, your ##H## is in some basis, let me use hats for...

Be careful, what is the argument? If you write ##H(t)## or ##H(\mathbf r)## it is not the same as ##H(\mathbf k)## (##\mathbf k## being...

I do not know if this has been brought out. There is this theory of Janus universes (as in Janus the god with two heads). Where...