5:54 AM

3 hours later…
8:33 AM
I don't like the phrasing "This section considers..." in formal writing. I prefer, "In this section, we consider...". The first one is very common, but I dislike it because anthropomorphism feels informal. Do I make a valid point, or should I adjust and start using the first phrasing?

8:58 AM
I suspect people care less than you think. Just use whatever phrasing you want, and if the editor doesn't like it they will tell you so (or just have a subeditor change it!).

9:37 AM

10:01 AM
@DanielSank you probably figured it out by now, but Mathematica often returns expressions unevaluated if the inputs you used do not match any valid pattern for the function. Eg if you define foo[x_Integer] := x and call f[2.3] you'll just get back f[2.3]. In other words, you probably used the wrong format for the inputs

2 hours later…
12:18 PM
Hello everyone, I hope you are having a great day :)

4 hours later…
4:45 PM
@ShikiRyougi I was, then I saw the higgstory pun above ;)

5:06 PM
@B.Brekke I think both phrases are unnecessary filler - just write something like "We now consider", there's no need to talk about the section at all

5:49 PM
@fqq as we say we are always one pun away from fun
:P

Is there any notion analogous to "reversible adiabatic" change in quantum mechanics? The reason why I am wondering this is that Von Neumann entropy remains unchanged under unitary transformations just like thermodynamic entropy does under reversible adiabatic or more correctly isentropic changes...
Moreover, I can't help not seeing another analogy---adiabatic process ceases to occur when there is the transfer of heat between the system and the environment..and unitary evolution ceases to occur when there is an interaction of the system with the environment.
Are these observations mere coincidences or there is something going on?

1 hour later…
7:21 PM
@ManasDogra Uh, everything in quantum mechanics is reversible.
Oh I see what you're asking.
Yeah there's a pretty deep connection there. Wave function collapse is more or less a shortcut for saying "the thing I am observing interacted with some other degrees of freedom, so information is now held by stuff that I'm not observing, and as a result, the system I am observing appears to have collapsed".
The whole notion of "heat" in thermodynamics comes form the idea of describing a system with many degrees of freedom by only a few "macroscopic" degrees of freedom. We knowingly ignore a lot of information about the system when we use thermodynamic language.