The h Bar

David Hammen

16:00

@JohnRennie I clicked your link and I got this:

To be consistent with data protection laws, we’re asking you to take a moment to review key points of Google’s Privacy Policy. This isn’t about a change that we’ve made – it’s just a chance to review some key points.

Slereah

My paper idea rests on me being able to solve that field

Either that or like

I need to do it via path integrals, maybe

David Hammen

We’ll need you to do this in order to continue using Google services.

Slereah

That way I don't need to have the basis for the field

user116211

@0celo7 His answers are alwwayyyyys long.

Slereah

(maybe)

Timaeus always sounds like he knows what he's talking about but his answer will never be an answer to your question

John Rennie

16:03

@DavidHammen that's odd, the link is just https://www.google.co.uk/search?q=mexican%20hat%20potential

user116211

He never came in chat though.

M Barbosa

@JohnRennie thanks that's awesome! Had not heard of that name before lol

0celo7

Chrome has told be before that google.com is known to carry malware

user116211

@Slereah: Did you ever try Physics Overflow?

0celo7

^

PO is generally better than PSE

No tyrannical moderation

Slereah

16:05

Well I can send my question that way I suppose

Import request sent

David Hammen

@JohnRennie It turns out I wasn't logged in to any of my google accounts. I have three (soon to be four, hopefully): one for work, another for stuff peripherally related to work / my nerdishness (cough physics.SE), and another just for fun. As far as I can tell, there's no way to delete my google account that was specific to my previous job. I just can't access it (which is a good thing). I'm trying to convince my new employer that my previous employer had a good idea.

@Ocelo7 -- Be careful, you might get what you asked for. While PSE's moderation is light, it does not let me tell you that you must be a moron since your left arm is much longer than is your right arm. PO has no qualms about that.

0celo7

PSE's moderation is light?

Danu

@DavidHammen I don't think there is a point in engaging in this discussion ;)

dmckee

@0celo7 The Shog once called the PSE moderators "kittens by comparison" to the ones at MathOverflow.

0celo7

Calling a black-hole colored pot a "somewhat dark cooking device" is a bannable offense here.

dmckee

16:14

Take that for what you will.

0celo7

@dmckee MO is for professional mathematicians.

Danu

0celo7 just loves being a victim :P

0celo7

@Danu No

dmckee

@0celo7 Read what the tour says about Physics lately?

0celo7

@dmckee What tour?

M Barbosa

16:15

I really think SO is one of the worst

0celo7

@Danu Currently listening to DMX, that old enough for you?

M Barbosa

And honestly no one hardly ever answers a question on there, it's mostly speculation and making fun of the person's code

David Hammen

Note: I have yet to retake the harassment training at my new job. I do know however that making jokes about one's gender, one's age, one's religion, one's heritage is completely out of bounds. But if your left arm is much longer than your right arm, I can joke about it. That does not fall into the category of "protected", anywhere. The last harassment training I took used that as an explicit example.

0celo7

Sounds like a ~~disability~~ alternate ability

Danu

@0celo7 Ok-ish. Listen to it at times, but not very much.

@0celo7 Think about the possibilities in bed!

0celo7

16:19

@Danu I need more details

@DavidHammen Is one really long or one really short?

Danu

@0celo7 Lie down and try it out ;)

David Hammen

@Ocelo7 - No. Some details are best left in private.

John Rennie

@DavidHammen Eh? Is this a euphemism for having asymmetric genitalia?

M Barbosa

lol

John Rennie

I love the audacity of some of the homework askers. This chap isn't even giving the usual pleas of I tried but can't do it. He's just come straight out and told us to do the problem and post the answer :-)

-1

Q: Show that there can be no net charge in a region in which there is uniform electric field

Refer above. Electrostatics question. Can you do the proof mathematically and post?

Slereah

16:33

at least offer some money

John Rennie

Shall I comment saying I'll do it if he pays in Bitcoin?

user116211

Damn! My cv quota is finished ;(((

Danu

@JohnRennie My body says yes, my brain says no.

Slereah

Hm

David Hammen

@JohnRennie -- No,that's probably protected. I was being quite literal when I wrote about having one arm longer than the other. On the other hand, at my previous job, my supervisor (a VP) and the office manager were both females. After grilling me before they made the job offer official, they asked me what I liked to do for fun. I knew what they meant, so I answered "I love taking my three lady friends on romantic walks through the woods and down to the beach!"

My three lady friends? Check my icon. They are real dogs. Quite literally.

Slereah

16:36

I do have the vacuum to vacuum transition amplitude for a free field with path integrals now

I wonder how easy it would be to adapt it to a wormhole scenario

Maybe...

Maybe I should do some GHOSTS???

John Rennie

@DavidHammen :-)

Slereah

Imposing some condition on the path integral so that it only integrates on the correct field configurations

Like... $$\int \mathcal D \phi(x) \delta(\phi(x_1) - \phi(x_2)) e^{iS}$$

I dunno

0celo7

@JohnRennie I did it for free.

John Rennie

@0celo7 you just answered a homework question. Why did you do that?

0celo7

I'm a rebel

Slereah

16:40

$$\int_{\partial D_1} dx_1 \int_{\partial D_2} dx_2 \int \mathcal D \phi(x) \delta(\phi(x_1) - \phi(x_2)) e^{iS}$$

Something like that

Does that sound like a reasonable thing

Some kind of WORMHOLE GHOST

Like in Event Horizon

0celo7

@JohnRennie dw, I VTC'd

@Slereah Wormhole Faddeev-Popov?

David Hammen

@JohnRennie -- Regarding my so-called romantic walks through the woods: My wife has joined me twice on those walks in the last seven years. Both times she has said "never again!" These so-called woods are infested with swamps, mud, briars, spiders as big as one's hands, and poisonous snakes. My arms are a complete mess under UV light. My three "lady friends" (my three female dogs) love it when I let them loose in that mess.

Slereah

I prefer to call it a Lereah Ghost

John Rennie

@0celo7 yes, but by providing an answer you're just encouraging the OP to ask more homework questions.

Slereah

B)

0celo7

16:42

@JohnRennie Hmm

John Rennie

The reason we don't answer homework questions is to discourage people from asking them. It's not that we're unhelpful bastards, we just don't want to be swamped by people trying to get us to do their homework.

5

0celo7

@JohnRennie I've read all of the meta posts on it

Slereah

probably a smart idea

Danu

@JohnRennie We're discussing this exact topic in the Mathematics chat right now.

0celo7

@Danu Why didn't you link the chat

I can never find their chat

it always takes me 5 minutes of hunting

Danu

16:44

chat.stackexchange.com/rooms/36/mathematics

0celo7

danke

Slereah

^wormhole ghost

0celo7

good god

Slereah

Hm let's see

0celo7

-2, wtf

Slereah

16:47

A spooky ghost in gauge theory is $\int \mathcal D A \delta(G(A))$

David Hammen

I'm a mentor at a potentially competing site that does answer homework questions. There's a big caveat: The person asking the question has to have done some homework. Asking "Do my homework for me!" doesn't work.

Slereah

With $G$ some gauge fixing condition

I think that should be fine too

0celo7

@DavidHammen I've been stuck on a homework problem for a day now

John Rennie

@DavidHammen most of us would regard the effort put in by the OP as an important factor. Where the OP has made a genuine attempt to tackle the problem themselves we'd probably stretch a point and answer, or at least give a hint.

But all too often the OP is just being lazy.

David Hammen

So ask at that competing site. You should be able to find it if you have a decent amount of google-fu. Since it is a potentially competing site, I am not going to mention it by name. @JohnRennie, you can let me mention it by name.

Danu

16:50

lol @0celo7 deleted it yourself after all?

0celo7

@Danu Well clearly it was unwanted!

Danu

@DavidHammen It's fine---you can name Physics Overflow.

0celo7

I thought I had a nice solution though :(

John Rennie

Nobody's going to care if you mention it.

David Hammen

Oh gosh. It is not physics overflow.

0celo7

16:51

Physics Forums?

John Rennie

This isn't a competition, and we're not jealous of other sites.

David Hammen

@ocelo7 -- Bingo!

0celo7

I hate Physics Forums @DavidHammen

You can never get answers from the threads

They all have the following layout:

Problem I need help with

Some dude giving a vague hint

Pointless back and forth about stuff I already know

Oh! OP figured it out but doesn't explain

John Rennie

Forums have their place, but the PSE is specifically intended not to be a forum. If people wish to discuss things that's what this chat room is for.

Slereah

Also physics forum has a lot of ads

Secret

16:54

Hi guys, I have a wavefunction collapse question that does not involve entanglement:

Suppose I have a set up containing one electron. 8 light minutes away I placed a detector B that can read the spin of the electron (and can flash red if spin up, green in spin down).

Suppose I have a friend Ann standing next to detector B.

Now I use another detector A next to the electron unit to measure my electron spin. Suppose my measurement collapse it to spin up. will I expect 8 minutes later, Ann will inform me her detector flashes red?

Slereah

Hm

If I have a follow up question to my wormhole question

0celo7

A first-principles proof that the normal bundle is a manifold might be the hardest thing I've done in a while.

Slereah

Can I call it [question] II : electric boogaloo

David Z

@DavidHammen there are no rules against mentioning competing sites. For the record.

0celo7

@Danu I take if you wouldn't care to provide a hint?

Danu

16:56

@0celo7 What?

0celo7

@Danu I'm trying to prove that the normal bundle is a smooth manifold.

It's not working

Yes, I checked Lee, yes I understand his proof.

But I have literally none of those tools available to me.

David Hammen

Physics Forums have very strong reasons for that format. This site (physics.SE) is not intended to be a homework help forum. We generally close questions related to homework, for good reason. Physics forums does not do that. Helping students to learn is their primary reason for being. That means lots of what would be duplicate questions here get posed, over and over again.

3

Danu

@0celo7 Normal bundle to what?

0celo7

@Danu A normal bundle of a manifold in $\Bbb R^k$.

I don't have slice charts available, I'm not even sure if I have frame fields

Danu

A submanifold you mean?

An embedded one?

0celo7

16:59

@Danu See, Milnor and GP define manifolds as embeddings

but they don't use the term "embedding"

John Rennie

Right, I'm off to read this weeks New Scientist. See you all later.

Secret

My guess is that when the electron get projected to e.g. spin down eigenstate, that information will need to travel with an upper bound of the speed of light to reach Ann, thus she will see the detector B flashes red. However I am not really sure if there is any chance the information becomes distorted somehow during the travel and causes the detector B to flashes green instead

Danu

@JohnRennie See ya!

0celo7

I'm stupid, I haven't checked GP...

It might be in there...

Aha!

At least a partial proof

@Danu Thanks for letting me @ you :P

Now you know what it's like to be ACM

David Hammen

@JohnRennie @JohnRennie See ya!

Danu

17:02

@0celo7 you could try to go through corollary 10.36 in Lee.

Existence of local frames is a triviality anyways

0celo7

@Danu I know how to do it via bundles!

Danu

Ah, shite he uses slice charts there too.

0celo7

I'm saying I don't have that technology available

Danu

So prove the technology first?

0celo7

@Danu I know!

@Danu Yeah like you're supposed to invent slice charts for an exercise without a hint?

@Danu and Milnor does not even define the notion of a fiber bundle

Danu

17:04

What class is this anyways?

I don't believe that submanifolds are not discussed before normal bundles.

0celo7

@Danu Differential topology

Danu

Then you should be able to use "standard lore" i.e. slice charts IMO :P

0celo7

@Danu Milnor does not really discuss these

GP uses slice charts too :/

Guess I'm inventing slice charts in this proof :)

ACuriousMind

17:30

@Danu nope

0celo7

@Danu I guess Milnor wants me to magically come up with the theorem on page 15 of GP...

These exercises are way too hard

Danu

@ACuriousMind OK.

Slereah

Hm

Maybe my spooky ghost idea should first be tested on a cylinder spacetime

0celo7

17:46

Hory shite it's already the 12th

Slereah

Yes

AMA in two days

Danu

How are you doing @ACuriousMind

ACuriousMind

Beginning to feel alive again after a terrible hangover

Slereah

So @ACuriousMind

What do you think of the

SPOOKY WORMHOLE GHOST idea

ACuriousMind

Is that a movie pitch or a physics idea?

Danu

17:57

@ACuriousMind Had a good time?

Slereah

Can't it be both

I'm trying to compute quantum things for spacetime surgery wormholes

ACuriousMind

@Danu Yeah, the party was excellent

Slereah

And I have this vague idea to do it with path integrals with the following method

$$\int_{\partial D_1} dx_1 \int_{\partial D_2} dx_2 \int \mathcal D\phi(x) \delta(\phi(x_1) - \phi(x_2)) e^{iS}$$

Or something like that

Though technically that's only half the conditions for spacetime surgery on fields

There's also $n_1 \cdot \nabla \phi(x_1) = -n_2 \cdot \nabla \phi(x_2)$

Not sure if I can use both here

ACuriousMind

@Slereah I'm not sure what that's supposed to be

Slereah

Well similarly to Fadeev Popov spooky ghosts, I'm trying to remove all field configurations where the field isn't of the same value at the boundary of the wormhole

Does that sound like a good idea

ACuriousMind

18:01

of the same value as what?

Slereah

Well the field that enters the wormhole at a point and the field that leaves the wormhole at the identified point should have the same value

ACuriousMind

If the two points are identified, i.e. the same point, how could it have a different value?

Slereah

Well the trick is

I am doing this as though it was Minkowski space

But with identifications to make it work

(Because otherwise I have no idea how to solve it)

ACuriousMind

Why is a field "leaving" or "entering" the wormhole to being with - a field is just some assignment of values to spacetime points, what do you mean by "entering"?

You might need to describe the setup in more detail before I can say anything about this

Slereah

Well Minkowski surgery is like

Take Minkowski space

Remove two identical closed volumes from it

Identify the boundaries of those removed volumes

0celo7

18:06

@Slereah What is the metric on the remaining piece?

Slereah

The metric is... kind of weird

Like it's Minkowski space everywhere, but you have kind of a Dirac distribution at the boundary

Metric is $C^1$, smooth everywhere except the boundary

0celo7

wew lad

that seems terrible

What's on the docket today...failing at topology exercises...check

Slereah

It is less bad than doing a smooth intrauniverse wormhole, tho

I tried my best on that front but jeez

0celo7

Obtain more food

Wrapping paper

I need to find a printer

oh and homework

M Barbosa

The Q&A really needs to be cleaned up. Last few questions have been horrendous!

0celo7

18:11

I can ask some good questions

M Barbosa

Fire away about 10 and the bad ones will get pipelined down @0celo7

0celo7

@MBarbosa what's the link

Slereah

Hm

M Barbosa

@0celo7 to a bad one?

Slereah

I recall that what's his name has a whole book section on path integrals on circles and such

I should try to see if my spooky ghost idea is equivalent to that at least in that case

M Barbosa

18:17

-4

Q: Acceleration of the body

Q) If v is the velocity of a body moving along x-axis, then acceleration of body is: (1) dv/dx (2) v dv/dx (3) x du/dx (4) v dx/dv Please provide the explaination of the correct option to me as well.

newtonian-mechanics

Slereah

👻👻👻👻👻👻👻👻👻👻👻👻👻👻👻👻👻👻👻👻👻👻👻

0celo7

> Congratulations! Your $5 Gift Card for The Springer Shop

Why thank you Springer

@MBarbosa no to the Q&A

Slereah

$5 won't even buy you a one page article on Springer

Hell

user116211

@Slereah not even a comic book ;((

M Barbosa

@0celo7 I was meaning the Q&A feed in general but "Acceleration of the body" is a good example ^^

Slereah

18:19

I don't even need to do it for QFT

0celo7

@Slereah It also doesn't apply to MyCopy books >:(

Slereah

I could try it for non-relativistic QM

Hm

user116211

@0celo7 why not $50? Damn Springer ;\

Slereah

I could try to apply a wormhole for non-relativistic QM, first by hand and then by path integrals

Maybe

at least within some limits

It's pretty easy to do for geodesics rather than fields

0celo7

18:38

Why is @JohnDuffield here

Slereah

He has the evidence

0celo7

oh god

I thought I cleaned that up

Danu

Lens spaces awwyis

0celo7

typo after "Figure 2"

missing period

Slereah

@0celo7 you might be pregnant

Danu

18:41

@0celo7 ?

Ah

Its name.

Thanks

0celo7

I guess I could have been more precise :P

Secret

Wow, you guys are drawing a "conlinder" (basically imagine folding a cylinder except the cross section of that rectangular piece of paper is a cone)?

Slereah

what

0celo7

anyway, what kind of pussy needs pictures

obviously one who doesn't understand the theory

Secret

* sorry mistake, that's not a conlinder, because the base of the cone (e.g. in $S_z$) is held fixed as it glue around $S_w$*

So I am guessing, all sets of points indicated by the blue dots and line (since the previous line said the identification is an equivalence class, it is kinda implying I basically have many such pairs of blue points and lines on figure 3, except not drawn for clarity?) are the points being identified in lens space?

and that the two blue points substends an angle of $e^{\frac{2\pi i}{p}}$ relative to the xx' line?

Slereah

19:01

what if all the aliens are dumb tho

Maybe they're all space bogans

Secret

he obviously completely missed the point -_-

0celo7

@Slereah I'm pretty sure e.g. ACM is an alien

Secret

When an exit path exists, they will go straight through it, this is their nature that you cannot change

David Z

19:36

@JohnRennie awfully generous of you to offer this

(IMO)

M Barbosa

@JohnRennie was the homework question police for today

ramsay

20:49

.

What is shift+enter command or iphone

0celo7

0

Q: Quantum oscillator transition amplitude

I have a quick question regarding an equation in my textbook. It's about calculating the probability transition amplitude of a quantum oscillator. Why is this true? The difference between the first and the second row seems to be small. There is a minus sign before $\dfrac{i}{\hbar}$. In the to...

integration quantum-mechanics

???

@Slereah you might have a better chance posting your stuff on Math SE

Slereah

Yeah might give it a try if it doesn't work out

Though I'll have to do it in a more math friendly fashion

Is there a name for that math-wise

It's kind of a connected sum of a manifold to itself

0celo7

What?

A name for what

Slereah

The whole cutting out a volume and identifying it

0celo7

> Since your interests are GR and Quantum Field Theory, with maybe some insight into Quantum Gravity (QG), could you summarize with some technical reasonings, what is known and what key findings are still needed for Hawking et al's conjecture that the BMS super translation symmetries and conserved charges are the basis for doing away with the information paradox?

lol

you're fucked if you have to answer that

Slereah

21:03

yeah I don't know shit about that

0celo7

@Slereah that's literally what surgery is

Slereah

I guess

mb there's a math paper about it

Like solving PDEs in surgery manifolds

0celo7

guaranteed

there's multiple shelves of books on surgery in the university library

(the topological kind)

Slereah

yeah but do they try solving PDEs on 'em

0celo7

Don't know

@Danu talked about surgery once or twice

Slereah

21:06

Also more importantly I need the Green function

0celo7

My leg hair is shedding :(

Slereah

I've seen a few papers working out specific solutions on surgery spacetimes

But I want the vacuum expectation value of things

0celo7

oooo, shoe store telling me I've got a reward

Slereah

Surgery theory was introduced by... Milnor

Damn Milnor again

Oh god I hope I don't have to learn Morse theory

0celo7

You'll have to learn topology first

Slereah

21:13

Eh

Maybe I can keep it blackboxed

Hm, what to search for

I need to think like a topologist

I'm guessing they would talk about HARMONIC FUNCTIONS

Can't really find shit on the topic

Danu

21:37

@0celo7 Hmm?

0celo7

@Danu Mmh?

@Danu Slereah needs help with surgery

Slereah

Yes

I need a disk cut out

Danu

I only know a tiny bit about the topology of surgery---no PDE's

M Barbosa

22:33

damn

Slereah

already deleted

M Barbosa

hahahaha nice. Pretty unclassy to call someone out on the meta like that

0celo7

what happened?

M Barbosa

someone called out CuriousOne on the meta

got deleted though. It was a pretty long grievance

0celo7

oh?

What was it about

M Barbosa

22:44

The user claimed he was giving out wrong information about QIT

most of them were on that user's questions which makes it even funnier

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