The h Bar

In quantum physics, Fermi's golden rule is a simple formula for the constant transition rate (probability of transition per unit time) from one energy eigenstate of a quantum system into other energy eigenstates in a continuum, effected by a perturbation. This rate is effectively constant. == General == Although named after Enrico Fermi, most of the work leading to the Golden Rule is due to Paul Dirac who formulated 20 years earlier a virtually identical equation, including the three components of a constant, the matrix element of the perturbation and an energy difference. It was given this name...

obe

@0celo7 Foundations and frontiers book is really nice.

I'm reading it right now.

Should I buy it to replace carroll?

It doesn't talk about manifolds.

0celo7

dude how should I know

get Wald and see what happens

obe

1:06 AM

Ok.

0celo7

I still think you should just play some video games

@obe I have a homework break

you have to have a QM question

ask anything

I'm bored

DanielSank

1:21 AM

@0celo7 No, thanks.

0celo7

um, ok

@Huy up late?

obe

2:03 AM

@0celo7 The answer to all my questions is: did you even read the chapter?

It is true though, therefore I don't ask and instead re-read.

0celo7

are you re-reading right now

obe

Reading the QFT notes.

The lectures are far more detailed and even review basic qm.

There are some people in the course who know less qm than me.

0celo7

::sigh::

you want to know the most

not know more than the least

obe

You're right, fail.

0celo7

be a supremum, not an infimum + $\epsilon$

3

obe

2:10 AM

Will that be your new catch phrase?

0celo7

no?

my catchphrase is

read the chapter

obe

The detail in shankar is overwhelming though.

0celo7

my other one is

Zee talks about that

obe

it's in shankar... it's in zee...

do I have to relive this?

0celo7

Jul 24 at 14:55, by obe

@0celo7 dw 70 days at most shankar will be done.

did you keep that promise?

I'm bad at date math

obe

2:14 AM

;(

FenderLesPaul

3:39 AM

@0celo7 b-but

I love you

Cornell University Confessions
10 hrs ·
#6163
For the cute Indian guy playing Simon and Garfunkel on his guitar: you have a sweet voice.

=D

someone appreciates my singing yay

0celo7

3:54 AM

wtf

that was not me

your singing is a distraction

you know I disapprove

@FenderLesPaul little albert told me what you did

he was hungry

and you gave him a fucking GR textbook

you're a monster

FenderLesPaul

he was hungry for knowledge

lil alby loves some sweet knowledge

skill patrol

4:40 AM

Have you ever played the sitar? @FenderLesPaul

FenderLesPaul

5:31 AM

@skillpatrol no but I really want to learn

Danu

7:43 AM

Hi @ChrisWhite

yuggib

8:02 AM

@Danu are you waiting the plane?

Danu

No, I'm only flying in the evening

yuggib

So you will lose today's "match" against JD... :-D

Danu

Meh, I've decided to really stop responding.

Slereah

hey hey

skill patrol

Yo Yo

:-)

Danu

8:05 AM

Yesterday was enough to demonstrate in crystal-clear fashion that he is not actually interested in explaining physics in an experimentally-backed fashion; directly contradicting QED and all.

skill patrol

E&E is simply a crank; nothing more, nothing less.

Slereah

Well duh

yuggib

@Danu His last statements were that he taught physics to us; and you in particular :-P

Slereah

What have I been telling for weeks

yuggib

and that you failed to say thanks to him...

Slereah

8:07 AM

and like most cranks, if left unchecked, all conversations become about him

yuggib

@Slereah Personally, I am just having some fun

Slereah

Oh sure, it's fun now

Now imagine in a few months when he has still not budged and continues to say the same things over and over

yuggib

Yeah...well to stop him doing that you would have to ban him

ignoring would not be enough

Slereah

my point indeed

skill patrol

True, it will get ugly.

Popcorn doesn't come cheap.

yuggib

8:11 AM

But I do not think he is doing harm to anybody. He provides some bizarre (and not even wrong) ideas; but experienced people know better, and inexperienced ones have plenty of literature to get informed and form their own ideas

Anyways, I agree that arguing with him is a complete waste of time, for he systematically refuses to address the issues pointed out to him. But then he starts to mock other people and to be disrespectful, as yesterday with @Danu. That is well worth some disciplinary action IMHO

Slereah

Burning at the stake

Danu

8:29 AM

@yuggib Ba-dum-tsss

yuggib

@Danu You should feel lucky that he spent some of his precious time to enlighten you.

Danu

@DanielSank Correct.

Vicious Circle & Nocturnal - Last Chance Saloon

►

0celo7

11:36 AM

I feel pretty enlightened.

0celo7

11:54 AM

My question got locked.

Now I'm infamous.

yuggib

you could see that coming...

they promised a discussion on meta anyways...

0celo7

I wonder what will come of that discussion

Discussion about what

yuggib

Don't know

about the issue

John Duffield

@DanielSank : no. CuriousOne is some old curmudgeon who goes round closing down questions. I'm one of the good guys who answers them. Se this answer where he was carping as usual.

0celo7

what is the issue?

my post?

John Duffield

12:05 PM

@Danu : I didn't contradict QED at all. I put you straight on the photon-photon interaction as per the Breit-Wheeler process. You learned something from me.

0celo7

@JohnDuffield Show us the term in the Lagrangian.

You do know what that means, right?

John Duffield

@DanielSank : yes, photons interact with photons directly. The Breit-Wheeler process is where photons interact with photons. Directly. Surely you know all about this? See this report from Imperial.

@DanielSank : it's a photon-photon interaction. The front portion of a photon is akin to a partial positron, the rear portion is akin to a partial electron. The virtual electron-positron pair in articles like this are virtual. As in not real. Not present.

Rigor

How do you @JohnDuffield define: real?

yuggib

@0celo7 "The" issue

everyone knows the issue

John Duffield

12:24 PM

@Rigor : I define it as in actually present. Virtual particles aren't real particles. There's this dreadful cargo-cult myth that virtual particles are short-lived real particles that "pop" into existence like magic, then pop out of existence like magic. It simply isn't true. Virtual particles are "field quanta". It's like you divide the electron's field up into little abstract chunks.

Then when the electron and the proton attract one another they "exchange field" such that the hydrogen atom has very little in the way of a field. Hence the concept of exchange particles. But there aren't any photons flitting back and forth. Hydrogen atoms don't twinkle.

@0celo7 : no. I spent a lot of time answering your question yesterday, with good references to hard scientific evidence and robust physics, and very little in the way of opinion. You ignored it all. And Timaeus's answer too. Timewaster.

Rigor

@JohnDuffield How can you be so sure?

Danu

John, since you're evidently too ignorant to do some Google searches I did it for you. Here, it is shown how the Bteit Wheeler process does not use direct photon photon interactions

images.natureworldnews.com/data/images/full/5536/this-shows-theories-describing-‌light-and-matter-interactions.jpg

Bye for now

Rigor

@Danu 404 not found

The requested URL /data/images/full/5536/this-shows-theories-describing-â€Œâ€‹light-and-matter-int‌eractions.jpg was not found on this server.

yuggib

natureworldnews.com/articles/7116/20140519/…

John Duffield

@Rigor : maybe he meant to link to this. The web page doesn't seem to work quite right.

"Researchers have tried showing that matter can be made from light. But, these tests often failed because they had to include particles that have mass. Now, physicists at the Imperial College London have found a way that could help scientists show that one can create matter from photons only."

Rigor

12:42 PM

thanks for the link

John Duffield

@Rigor : I'm sure because I've read a lot of stuff. See for example Matt Strassler's article: "The best way to approach this concept, I believe, is to forget you ever saw the word 'particle' in the term. A virtual particle is not a particle at all."

Also see anna v's answer here: "Thus virtual particles exist only in the mathematics of the model used to describe the measurements of real particles". I understand that anna v is a former particle physicist.

yuggib

You should stop spamming this chat addressing the wrong questions. No one here is seriously disputing the fact that virtual particles emerge as a mathematical artifice to do computations. What has been asked to you is to explain, in a convincing way, your interpretation of some observed facts. In particular, to explain the interpretation that what is observed in the Breit-Wheeler experiment is a consequence of a direct photon-photon interaction.

Slereah

No you fool

Do not talk to him

You'll only make it worse

yuggib

12:58 PM

The latter is indeed an interpretation, for the experiment only says that given a laser beam and additional photons, then you observe the creation of particle pairs.

John Duffield

@David Z : re your discussion on 0celo7's locked question, note that my answer is laden with robust references and contains very little in the way of personal opinion.

yuggib

@Slereah Nah...you will always see the same spamming going on and on...whether you answer it or not.

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