The h Bar

Stan Shunpike

10:01 PM

@ACuriousMind I thought it was supposed to do that. Lolol

Yeah, it seems to change every few days or so

I kind of like it. Its less boring.

It was grey, then yellow, now pink, its been green

Its weird cuz @bolbteppa seems to have the same color every time so I dunno why mine mutates

Is it a glitch?

ACuriousMind

I don't think it is supposed to change without you doing anything

At least, you're the only one whose gravatar is going that

Stan Shunpike

Weird. I like it though.

dmckee

Not shouting 'No, your "thought experiment" is no different from all the other I figured out how to go faster than light "thought experiments" on the site, dmanit!'.

Nor 'You have to understand the theory before there is any value to trying to do a thought experiment!'.

Stan Shunpike

@dmckee what is this? Quotes of the day?

dmckee

And especially not 'Having seen a documentary is not the same as understanding the theory!'.

@StanShunpike It's venting.

Nothing really important

Stan Shunpike

10:12 PM

It sounds like the kind of argument one would have with someone on vixra

MARamezani

@dmckee My post's locked back at meta, so I found here to talk:

I'm baffled!

The Q first got migrated, then marked as duplicate, then not migrated, then another comment on a locked post... I give up!

Though I admit that when I saw the question was a dup, I deleted it. I thought it was something I idioticly asked that everyone knew the answer for. Then it got migrated again....

dmckee

@MARamezani See meta.stackexchange.com/a/126982/2509 .

By deleting the version on meta.physics.se you rejected the migration. It was fine existing as a duplicate.

Stan Shunpike

@ACuriousMind I just read John Baez page on Noether's theorem. He has very poor notation despite simplicity of his explanations. As you know, for typical Lagrangians, the input is $q(t)$ and $\dot{q}(t)$ but Baez then discusses sending q to q(s) to discuss how things don't change when you apply a one parameter family of transformations or something like that. What does the q(s) stand for? Is he manipulating the t or introducing some new variable s?

math.ucr.edu/home/baez/noether.html

MARamezani

@dmckee So how do you suggest we clean this mess?

dmckee

@MARamezani Just leave it as is.

MARamezani

10:18 PM

Alright thanks mod. I'm off to sleep.

Stan Shunpike

@dmckee So what do you think of my constantly changing gravatar. Is that supposed to happen or is it a glitch? I like it, just curious.

@ACuriousMind was the first to notice besides me seemingly

dmckee

@StanShunpike Not a clue. I thought that a gravitar was linked to the has of the OpenID you used to log in or something. DO you have more than one connected to the account?

Stan Shunpike

Nope. I just use one account and its not connected to anything.

It doesn't really matter, I am just surprised. I thought everyone's did that.

ACuriousMind

@StanShunpike $s$ is a real number parametrizing the transformation of $q(t)$ into some other $q_s(t)$ such that $q_0(t) = q(t)$.

(And, smoothly, $\lim_{s\to 0}q_s(t) = q_0(t) = q(t)$)

Stan Shunpike

Ah, there ya go! So I worked out the proof for myself. What would be a good classical field od QFT case to look at to see how Noether's theorem is useful. I still don't really see what's significant about it even though I know it must be important.

Or*

ACuriousMind

10:31 PM

@StanShunpike Well, write down the Lagrangian for a free particle and derive conservation of momentum from invariance under spatial translation $q_s(t) = q(t) + s$!

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