The h Bar

Slereah

20:00

Good to know

0celo7

from MTW

nub

Slereah

nub is bun backward

(heheheh buns)

Slereah

20:23

Wait

The limit of a lattice wouldn't be De Sitter

It would be some homogeneous fluid spacetime

Wait it would just be FRW

Except static

What's the class of static FRW spacetimes

NEVERMIND STEPHANI WILL KNOW

Hey with $G_7$ it's the Einstein static universe!

Though I think a crystal permeating the entire universe would just be FRW really

And collapse

dmckee

Random thought ... occasionally we should pick some heavily duplicated topic and make an effort to find the most canonical version of the questions and answer and (a) close as many duplicates as possible with link to the canonical versions of the questions and (b) get the canonical answers under the canonical questions (mod powers required to merge).

Slereah

Damn giant crystal

dmckee

Anyone think this is a good idea?

Would anyone want to participate?

Slereah

@dmckee : Really I'm surprised that we don't have like

A wiki of common questions

dmckee

Of course I thinking about double slit questions and time dilation questions and so on.

@Slereah The setup doesn't really encourage it, thought I believe there is a [c++-faq] tag on Stack Overflow which might be a model if you wanted to go that was.

Slereah

20:30

Something where we can distil down the interesting answers into a nice version for future people

dmckee

I never really cared for it.

ACuriousMind

@dmckee Yes, I think this is a good idea. The problem is that it requires a good deal of effort, which is why I think it hasn't happened yet.

dmckee

@ACuriousMind Oh yeah. No point embarking on that kind of question without the commitment of a group of users to work on it.

@Slereah ArXiv dates to before the web. Article title have the form they do to (a) get them ordered in a directory listing and (b) not take forever to type into your ftp or gopher client.

::waits to see who has never heard of gopher::

0celo7

The furry little animal? Sure.

Slereah

@dmckee It's not the stone age anymore, daddy-o

I'm pretty sure it wouldn't be too difficult to rename them automatically

Identifier-date-author-title

Or something

I dunno

0celo7

20:36

daddy-o?

is there some secret familial relation here

dmckee

@0celo7 Obsolete slang indicating that I'm even more obsolete that the word.

0celo7

@dmckee aww, that's so sad

dmckee

But actually the word is from my parents time, which was slightly before the discovery of water.

0celo7

you're not even that old

you're only 3 years older than my brother...

skull petrol

Daddy-o dmckee

Slereah

20:39

My science folder has about 6000 articles

If I could sort them without having to rename everything by hand, it would be nice

dmckee

Slereah

Early chemistry wasn't too far off really

Fire, water, earth, wind, heart

dmckee

@Slereah Back in the day that would have been a job for perl. Thankfully these days it is a job for python or ruby or something

Slereah

By your powers combined etc

Don't insult Perl!

dmckee

@Slereah It is not possible to say anything about perl that is more insulting than just being perl.

Pathologically Eclectic Rubbish Lister

Slereah

20:41

shakes fist

Hey, you're an old man

skull petrol

Don't mess with daddy-o-dmckee :P

Slereah

How much FORTRAN did you do

dmckee

@Slereah I still get flashback to this very day.

0celo7

uh

dmckee

It probably doesn't rise above a couple hundred thousand lines. I was a lightweight.

0celo7

20:42

nuke engis still do everything in fortran

dmckee

@0celo7 Please tell me they are migrating to the more modern versions. Please.

I was pretty good at Fortran 77, but that is like being pretty good at using a flint axe.

Slereah

I did all I could to avoid doing computer stuff when I was in the lab

My thesis was all math

ACuriousMind

Wasn't KyleKanos still coding many things in Fortran (the modern versions, though)?

Slereah

And now I'm a software guy :(

dmckee

@ACuriousMind I think so. And Chris White, too.

Slereah

20:50

FORTRAN, COBOL, APL and ADA are the languages that won't die

0celo7

@dmckee Don't know.

@Slereah Because of GDP, no doubt.

Shit, even Latin didn't last as long as COBOL.

Slereah

Well it's mostly because people don't want to rewrite the hundreds of thousands of COBOL lines

They work fine

So it would be more money to replace them

Fallout 4 at 70%

Good thing I took the preorder

0celo7

wow

that's really slow

Slereah

IN MY DAYS GAME FIT ON A FLOPPY DISK

0celo7

you're not even that old

Slereah

20:53

I am

0celo7

you people need to chill

Slereah

My first computer was this

Oh that joystick

The memories

fuzzy memories because it was in 92

0celo7

when were you born?

Slereah

The Atari joystick was pretty shit

86

0celo7

@Slereah Might want to update your LinkedIn, doesn't say you're unemployed :)

Slereah

20:58

Eh.

The eh should be read thusly

Simpsons - The MTV Generation

►

I should also remove the "Angular JS" from it

I get a lot of offers but I really don't want to do Angular JS

0celo7

NUTS

Slereah

are you playing little army men

0celo7

what's that

NeuroFuzzy

@0celo7 @ACuriousMind is there any german "S" word that is the reason why action is denoted by S in QM?

Slereah

ACuriousMind

21:08

@NeuroFuzzy Not off the top of my head, the usual German word for action is Wirkung

Slereah

Could be latin, too

Go ask your local priest

ACuriousMind

I think the Latin is just actio :P

Slereah

No that's the magic spell to bring object

ACuriousMind

@Slereah That's accio, you muggle

Slereah

What is the symbol for accio

🎇

Slereah

21:33

Ugh I'm so tired of jokes about dihydrogen monoxide

The IPAC name of water is OXIDANE you berks

Kevin Driscoll

@AcuriousMind Hi, thanks for your comments on my question about this unusual Hamiltonian with regularized delta functions.

ACuriousMind

@KevinDriscoll You're welcome (although I don't have much of an idea how to actually resolve the technical problems in this case...)

TanMath

Hey all!

BTw, what is the physics chat session?

@0celo7 you got banned? from where?

Slereah

By the way

For you particle physicists

Did the Particle Data Group book come out yet?

TanMath

@Slereah can't you just look at the website for PDG

What is the physics chat session?!

@Slereah did you know dihydrogen monoxide will kill you?

Kevin Driscoll

21:45

@ACuriousMind Yes, then unfortunately you, myself, and my advisor all seem to be in the same boat. My suspicion right now is that I have not properly defined what it means for $\nabla^2$ to act on these functions. The definition I give in the post it just heuristic; there's no rigorous definition backing it up.

I imagine that if I defined its action properly, then all of the offending terms will cancel and I'll get 0 for the relevant integral.

ACuriousMind

@TanMath It's just a time when more-than-usual people show up here, and recent meta threads are discussed if need be. It's a relic from times when this chat room was far less lively.

Slereah

@TanMath No

It's a book you can't buy

You can only subscribe to it

And once a year, they send you one

For free

TanMath

@ACuriousMind did it improve the chat attendance?

@Slereah for free?

who is paying for it?

Slereah

"Classic Nintendo Games are (NP-)Hard"

heheh

@TanMath Government, probably

TanMath

@Slereah huh?

Slereah

21:49

I don't think it's extremely problematic because not a lot of people want to get the Particle Data Group annual report

Only insane people or people working in labs

John Duffield

@dmckee : I don't think it's a good idea. I keep seeing good interesting questions closed down by people who point to a so-called duplicate that isn't, and/or to some non-answer or crap answer. Sometimes this answer is written by one of the guys who closed down the question. And sometimes some of the guys who close down the question contribute zilch to the site. I think the focus should be on closing down the homework and the lazy questions.

Slereah

Oh, that's the title of a paper I have in my files

obe

I had 15 life saver peppermints todays.

ACuriousMind

@KevinDriscoll Well, here's one way that's onerous but often works: Since the smooth compactly supported functions are dense in L^p spaces, one can find a sequence of such functions $f_i$ convergent towards your $\psi_0(r)$. The action of any operator $T$ is then defined by $T\psi_0 := \lim_{i\to\infty} (T f_i(r))$. The problem is that it's not obvious how to find the $f_i$, and that it is not guaranteed that $T$ can be extended to $\psi_0$ (for instance in cases where $T$ isn't bounded)

TanMath

@JohnDuffield true, but there are still many duplicates...

ACuriousMind

21:52

Another way would be to replace the Delta-function by a regularization and take the limit at the very end.

Slereah

"The Onomastic Evidence for the God Hermanubis"

Better not put that one in the physics folder

ACuriousMind

Unfortunately, I don't know one decides which of these procedures, if any, is the correct one

@TanMath Dunno, it started far before I came to this site

TanMath

@ACuriousMind there is no meta post on it?

ACuriousMind

@TanMath Not that I'd know.

John Duffield

@TanMath : agreed. But IMHO the closing-down of questions is a bigger problem. It's as if there are people who can't answer questions who don't want anybody else answering them, and who carp when they do. Note what happened last night when I answered your chat question about tensors. Nobody else had bothered to answer it, but when I did, they started arguing and whining.

Slereah

21:58

Seems to just be a call for people to come to the chat once in a while?

ACuriousMind

@Slereah Pretty much

Usually, it attracts JohnRennie and TerryBollinger, which is nice

Slereah

Yep

I have a paper on the symmetries of the Dirac equation

Golly gee willicker there's a lot

TanMath

@JohnDuffield what arguing and whining?

John Duffield

@Tanmath : see this question for example. It was put on hold just as I answered it. And surprise surprise, I've got downvotes. I imagine they're from the people who closed the question. Note that I'm not the only one concerned about closing down questions. See this.

@TanMath : see here.

Physics Meta

0

Q: Deleting an answer and posting another one

I saw a question about the smallest effect of gravity ever measured, and posted what I believed to be an interesting answer about the forces in an AFM. When I came back a few hours later, I saw that my answer got a single down-vote, and zero up-votes. Further, some other answers had appeared. Bas...

discussion

TanMath

22:07

@JohnDuffield your meta post does mot show any concern about the closing of posts.. also, sometimes your answers are plain wrong so that could be the reason for the downvotes.

ACuriousMind

Oh, look, even an onlooker can tell that getting a lot of downvotes probably means something about the answers is wrong!

Slereah

heheh

"Can Mathisson-Papapetrou equations give clue to some problems in astrophysics"

I like this title because it betrays the process

"Hey look, this equation is cool!"

"Let's find a physics problem to apply it to!"

ACuriousMind

@Slereah Is the answer "No."? :D

John Duffield

@Tanmath : It wasn't my meta-post, it was Dirk Bruere's. And note that I give good references to back up what I say. See if you can pick one of my answers that's "plain wrong", and explain why. You won't be able to. If you could, people like ACuriousMind would have done it already, and he can't.

The question was "Ultimately, what will the Physics Stack Exchange Become?" Dirk Bruere said "Eventually what it will become is a place where anyone who asks any question will be referred to a previous answer before their question is closed down". Very observant I thought.

Slereah

"No alignment of cattle along geomagnetic field lines found"

That article has that title

But it has no cow diagrams

I am sad

ACuriousMind

22:16

@JohnDuffield I don't explain to you anymore why your answers are wrong because you have repeatedly shown you evade the question, move the goalposts, and attack strawmen instead of actually listening.

5

@Slereah :(

Slereah

"Floral Mimicry Enhances Pollen Export The Evolution of Pollination by Sexual Deceit Outside of the Orchidaceae"

Sexual deceit

Why do I have this article

John Duffield

@ACuriousMind : you have never explained why my answers are wrong. And I do not evade the question or move the goalposts or attack strawmen instead of listening. You're just carping and throwing out defensive accusations. The truth is you don't dare take me on, because you know I will embarrass you.

Slereah

"On the Motion of Falling Leaves"

yuggib

@Slereah I have to say that I used this journal

springer.com/psychology/personality+%26+social+psychology/…

Slereah

"The largest Last Supper: depictions of food portions and plate size increased over the millennium"

:D

yuggib

22:22

to find the most absurd titles of all science...if sexual psychology can be defined science

Kevin Driscoll

@ACuriousMind Ya, the second approach is certainly the right way to conceptualize the problem, physically. The problem is it's computationally much more difficult to solve, generally speaking. The first is so far out fo my wheel-house that I can't say. I understand it, but it's just not something I've developed the toolset to do. There a mathematical physics guy here who does QM, so I'm going to ask hi if he has any insight.

ACuriousMind

@JohnDuffield If you didn't even understand the discussions - here as well as in comments to your posts - I and others had with you were mainly about why what you write (e.g. about electrons being photons going round and round, or about your peculiar fixation on coordinate speeds) is wrong then I really have nothing more to say to you.

John Duffield

@Tanmath : ask ACuriousMind to explain to you why some answer of mine is wrong. He won't be able too. And he won't dare either. Also see stuff like this where he complains about running out of close votes.

ACuriousMind

@Slereah What can we say about that motion? "It's chaotic"?

Slereah

Hm

One of the math book in the folder has an author

Kripke

Officer Kripke D:

West Side Story-Officer Krupke

►

Oh, that was Krupke

nvm

John Duffield

22:29

@ACuriousMind : I understand the discussions. And this is no peculiar fixation:

ACuriousMind

@Slereah A math book in the same folder as a paper about falling leaves and sexual psychology? Your storage system is weird ;)

yuggib

@ACuriousMind sexual psychology was mine contribution to the weirdness

:-D

ACuriousMind

Ah, right...Slereah only had one about sexual deceit in plants :D

Slereah

@ACuriousMind It's a big "science" folder

yuggib

it is always important to know about the life expectancy of lesbian japanese macaques

Slereah

22:32

That is why I am sorting it

Currently I am sorting them into the physics-math-biology-humanities-linguistics folders

then I will sort physics into GR-QFT-EM-whatever else

etc

John Duffield

OK I'm off. Good night all.

Slereah

"Quantum finance"

heheh

ACuriousMind

Oh, so that's what a "quant" does ;)

0celo7

the stock market is just one big quantum fluctuation

Slereah

Quantum finance is just a book about using path integrals for financial mathematics

0celo7

22:38

can a quantum fluctuation have smaller sub fluctuations

Kevin Driscoll

the stock market is, to a good approximation, a kind of Markov process, so it shouldn't be a surprise that this kind fo stuff works quantitatively

ACuriousMind

It's a bit silly to call it "quantum" though when it is classical statistical physics where the path integral is actually more well-defined :P

Slereah

(The uncertainty principle for quantum finances is the market volatility :p)

@ACuriousMind Punchier title though

0celo7

Or the price of cocaine

Slereah

Hm

AtmosphericPrisonEscape

22:40

Sounds alot like quantum healing

0celo7

Or is volatility = volatility(cocaine price)

Slereah

For some reason I have a Chinese physics book in there

Chinese book on Hilbert spaces

0celo7

lel

Slereah

"Albert Einstein, A Jewish myth ((hoax, plagiarism, zionism, relativity theory, Hilbert, Poincare)"

Hm

0celo7

@ACuriousMind what

Kevin Driscoll

22:42

Wow. Over 120 answers with a score of -1 or lower. That's dedication.

Slereah

Another one for the crazy folder

0celo7

what great conversation did I miss :o

TanMath

@ACuriousMind what is wrong with John Duffield's answers?

0celo7

was playing BF4

@TanMath Most things.

TanMath

@0celo7 exactly what?

0celo7

22:43

@TanMath You're gonna have to pick one.

TanMath

-3

A: Do quantum fields and their exitations exist in space time?

Do quantum fields and their excitations exist in space time? To be purist: no. Spacetime is a mathematical space. It models space at all times. You can draw world lines in it, and light cones. But because it models space at all times, it's static. There's no motion in it. And photons move. H...

Slereah

Hey a Russian book

Seems to be math

In the math pile!

0celo7

@TanMath Well, I'm no field theorist and didn't vote it down.

But I don't think you can call the electron field a mathematical abstraction but say the EM field is real.

Slereah

"Do gorilla females join males to avoid infanticide? A quantitative model"

How did I end up with this

TanMath

what about this one?:

-2

A: I think I am misunderstanding Einstein's equivalence principle and his elevator

I'm having difficulties understanding why a gravitational acceleration can be guaranteed to be locally equivalent to an accelerating frame. Actually, it can't. See section 20 of Relativity: the Special and General Theory where Einstein said this: “We might also think that, regardless of the ki...

ACuriousMind

22:46

@TanMath Okay, start with this: "Photons exist, electrons exist, electromagnetic waves exist, and electromagnetic fields exist". It tells you nothing of substance, and it commits a category error: On the level of description where there are electrons and photons, there are no electromagnetic waves (because "electron/photon" is a quantum field theoretic concept, while "electromagnetic wave" is a classical concept). Mixing classical and quantum descriptions is just confusing and unhelpful.

Slereah

Oh boy, I reached the Principia Mathematica

I was way into this in 2008

Kevin Driscoll

When did you finally read Godel?

ACuriousMind

@TanMath The Einstein quote that follows is completely unrelated to the question because it is about classical fields in special relativity, not about the quantum fields the question asks about.

0celo7

@TanMath Global issue: His answers have a lot of words that don't answer the question, are pretty confusing and he throws in random other stuff

TanMath

@0celo7 and looks like he can't admit it either!

ACuriousMind

22:48

@TanMath It's completely unclear what arguments might be used to say that "The electron field is arguably a mathematical field, but the electromagnetic field isn't." On the level of quantum field theory, both are quantum fields.

Kevin Driscoll

It's kind of silly to appeal to 1929 Einstein on Quantum Field Theory. It hadn't been invented eyt.

TanMath

@ACuriousMind true...

0celo7

@TanMath re that GR question: I'm not even sure what he's talking about

Slereah

@KevinDriscoll Pretty soon after

0celo7

take that for what you will

but I'm not going to spend time trying to figure it out, either

ACuriousMind

22:50

@TanMath "I think it's better to take a tip from classical electromagnetism and say the photon field and the electron field are two aspects of the same thing" This is just plain out wrong. The electromagnetic field is a gauge vector field, the electron field is a spinor field. You can have a theory with gauge vector fields without spinors, and you can have spinors without gauge fields. They are in no way, shape or form "two aspects of the same thing".

Slereah

"Non-Linear Density Dependence in a Stochastic Wild Turkey Harvest Model"

Hm

ACuriousMind

@TanMath "There is surely no magical mystical mysterious way by which photons pop out of existence and electrons and positrons pop into existence. Or vice versa."...no one claimed that.

0celo7

@ACuriousMind Ha. WRONG. Electrons are just photons going round and round. /s

TanMath

@ACuriousMind but that is true.. virtual particles!

0celo7

@Slereah I think that's what they do in the mathematical ecology classes :D

ACuriousMind

22:52

@TanMath You might see from the amount I've written for this one answer why I am not keen on writing that over and over again for every new one.

TanMath

OK... conclusion - John Duffield's answers are bad and confusing and he can't admit it. I think he feels insecure or something...

How in the world does he have 4k rep?

0celo7

A few highly upvoted answers

user54412

@dmckee Actually never written Fortrash in my life (yes, I have strong opinions on the language). My first ~~language~~ love was C, and all my current work is a combination of C++ and Python.

0celo7

In the frequent users category, he has the lowest upvote/downlote ratio by far.

ACuriousMind

@TanMath Well...no. Virtual particles are just internal lines in a Feynman diagram, and you formally cannot ascribe the same status as to actual particles to them. There's no reason in the QFT formalism to think these lines represent anything physical, although unfortunately many physicist will use them for "layman's explanations".

@TanMath An upvote is +10 rep, a downvote -2. In principle, you can have all your answers at -3 with +1/-4 and still continually gain rep.

Slereah

22:55

@ACuriousMind It is quite instructive to see a detailed breakdown of Duffield's reputation

TanMath

@ACuriousMind so virtual particles don't actually exist? so then what about other stuff like hawking radiation?

@ChrisWhite python! yay!

Slereah

Hawking radiation does not need virtual particles

Kevin Driscoll

@Slereah Ya the basic idea was around in 1929 and 1930, but only to tree level. And not in an explicitly covariant form. I would say it took until the late 40s before anyone really understood anything about QED. That's when they could calculate the electron magnetic moment and such.

TanMath

@Slereah yes it does!

ACuriousMind

@TanMath Ah, well, that's just a manifestation of the Unruh effect, which doesn't need the idea of "virtual particles". The only thing you need to say is that a state that looks like vacuum to one observer can look like a state with real particles to another

Slereah

22:57

You don't even need particles at all, really

there's a simple enough argument which shows that (for the vacuum defined at infinity), a black hole radiates positive energy outwards and negative energy inwards

Woo, the pdfs are sorted in their categories

Now to sort the physics category!

There's 3400 files :p

user54412

@Slereah Indeed, there's an old, great paper that does this not only the energy/momentum but the angular momentum as well in the Kerr case, without touching a single wavefunction or Feynman diagram.

Slereah

@ChrisWhite Yep

The angular momentum analysis shows that the particle radiated statistically have their spin oriented such that the black hole's angular momentum diminishes!

user54412

I can't seem to find the paper now. Pretty sure it was ~3 authors, and pre-1960.

Slereah

IIRC the proof is in Wald?

user54412

Oh wait, Kerr metric is 1963.

Slereah

23:02

Also Visser has it somewhere

In his paper on gravitational squeezing

Kevin Driscoll

@TanMath @ACuriousMind I'm interested if you disagree, but I think of 'virtual paticles' as just being a analogy or metaphor that we use. What we generally ascribe ontological priority to is the operator-valued field. It's doing something which we can describe perturbitavely (sometimes) as the propagation of off-shell particles, but there's no reason to give them any kind of ontological existence.

Slereah

There's no reason to give anything in physics ontological existence

This is physics not philosophy

The point isn't what's real or not real

In the end the measurable components must just be what's measured

Although thinking of virtual particles as real is probably not a good idea

Because 1) the notion of particle doesn't even really exist in interacting theories 2) it's not even Lorentz invariant

(for virtual particles)

Kevin Driscoll

@Slereah I disagree. I think physics should be concerned with ontology and not just instrumentalism. I find it difficult to believe that physicists think "oh, no I don't have any ontological commitment to electrons."

ACuriousMind

@KevinDriscoll I agree. The problem is that it is almost never used as metaphor, but as an actual description one can use to reason about the physical process, and this often leads to absurd outcomes.

Kevin Driscoll

I think Bell was right when he said that Quantum mechanics needs an ontology of so-called Local Beables, and not just local observables

TanMath

23:07

@ACuriousMind so what is the actual physical process occuring?

ACuriousMind

@TanMath Stuff interacts. There is no description of quantum interactions that would be accessible to our classical intuition. (Which is probably why virtual particles are so popular, because they seem to offer such a thing)

0celo7

Stuff interacts.

Great.

Slereah

It is FIELDS

Except

It's fields on a Hilbert space

So it gets complicated

0celo7

Is Hilbert space real

I haven't seen it and neither have you

where is The Evidence for it

Slereah

I have Hilbert and the evidence

John Duffield

23:12

@ACuriousMind : methinks you should do some research, because Quanta of EM waves are called photons. And Einstein said what he said about a field being a state of space. That quote is absolutely relevant. NB: Einstein referred to the Riemannian metric. That's GR, not SR.

0celo7

@JohnDuffield What does Einstein have to do with this?

John Duffield

@TanMath : Re the electromagnetic field is a gauge vector field, the electron field is a spinor field. I suggest you ask a question about what sort of field the electron has. The answer will be an electromagnetic field. Classical electromagnetism is not the same as QFT, but they are describing the same reality.

@0celo7 : Einstein said a field is a state of space, and it can't have two states in the same place. So what you think of as two fields aren't two fields.

TanMath

@JohnDuffield me thinks you should realize that the community says your answers are wrong!

0celo7

@JohnDuffield You have have two states in the same place.

TanMath

4

Q: Are electron fields and photon fields part of the same field in QED?

I know in classical field theory we have the electromagnetic field. And Maxwell's equations show how electromagnetic radiation can propagate through empty space. I also have been reading about QED and I gather the electric repulsion between two electrons is mediated by a virtual photon. Also,...

electromagnetism photons electrons quantum-electrodynamics

read the first sentence in the answer!

John Duffield

23:18

@TanMath : I have a 4k rep because I give good answers. LOL, you may have noticed that some people here don't like it.

TanMath

"In our modern understanding, every electron is thought to be a localized excitation of the electron (or Dirac) (spinor) field Ψ(xμ), while every photon is considered to be an excitation of the photon (vector) field Aν(xμ), which is the quantum field-theoretic counterpart of the classical four-potential."

@JohnDuffield before, but not anymore...

@JohnDuffield you have been giving bad answers since around september...

John Duffield

@0celo7 : no, you can't have two states of space in the same place.

TanMath

@JohnDuffield yes you can...

0celo7

@JohnDuffield Two states of space? What does that mean? I thought we were talking about quantum states.

TanMath

@0celo7 i think we are...

@HDE226868 i didn't know you were a zooniverse guy!

John Duffield

23:24

@TanMath : no, virtual particles don't exist, they are mathematical abstraction. See anna v's answer here: "virtual particles exist only in the mathematics of the model". As for Hawking radiation, see this: "the particle that fell into the black hole must have had a negative energy". Only negative-energy particles don't exist either.

@0celo7 : the state of space where a gravitational field is, is inhomogeneous. That's what Einstein said. Google on electromagnetic geometry. You'll find Percy Hammond saying the state of space where an electromagnetic field is, is curved.

0celo7

We've come full circle to something that I've debunked over and over and over.

This is really annoying!

ACuriousMind

1 hour ago, by ACuriousMind

@JohnDuffield I don't explain to you anymore why your answers are wrong because you have repeatedly shown you evade the question, move the goalposts, and attack strawmen instead of actually listening.

You just have to let it go, else you'll be trapped in this Groundhog Day forever.

TanMath

I can't be bothered with @JohnDuffield 's answers now.. goodbye!

Kevin Driscoll

@0celo7 I can understand the skepticism about Hilbert space. It's certainly hard to see how the Hilbert space could have some independent existence.

But at the same time, to avoid complete skepticism we have to say that our model is accurately capturing SOME properties of nature. So presumably, there are some natural entities that have certain properties which make them behave like abstract vectors in a Hilbert space, although what those enetites are and precisely what the shared properties are, I can't say. Maybe no one could ever say.

0celo7

@KevinDriscoll That was a joke.

John Duffield

23:31

@Slereah : no, there isn't a simple enough argument which shows that a black hole radiates positive energy outwards and negative energy inwards. The clue to this is in the word black.

Kevin Driscoll

@0celo7 Ah, okay, sorry about that. It's kind of a pointed joke, ebcause its grounded in something that really does deserve ot be thought about.

0celo7

@KevinDriscoll It was a JD joke. He once said something like "I haven't seen X and you haven't either"

Ah, the best strawman

I said energy is not conserved in GR

and he said because I haven't seen an infinite energy machine, that is wrong

John Duffield

@0celo7 : all you've done is dismissed Einstein.

0celo7

@JohnDuffield I tend to dismiss people who are wrong, yes.

I think that's normal?

John Duffield

@ACuriousMind : what you mean is you'll dream up creative objections to my answers, but you won't defend them against things like the electron has an electromagnetic field.

HDE 226868

23:42

@JohnDuffield Wow, you really have a way of manipulating words. You should run against Trump. That statement - "the electron has an electromagnetic field" - is vastly different from what you wrote and defended earlier.

John Duffield

@0celo7 : Einstein wasn't wrong. And energy is conserved full stop. When you drop a brick some of its mass energy is converted into kinetic energy, which gets dissipated, then you're left with a mass deficit.

ACuriousMind

@HDE226868 That's precisely what I call "moving the goalposts".

HDE 226868

1 hour ago, by ACuriousMind

@JohnDuffield I don't explain to you anymore why your answers are wrong because you have repeatedly shown you evade the question, move the goalposts, and attack strawmen instead of actually listening.

Yep. That's about right.

John Duffield

@HDE226868 : it was a fair response to ACM's specious objection wherein he said they are in no way, shape or form "two aspects of the same thing". In classical electromagnetism we talk about the electromagnetic field. In QFT we talk about the electron field. These are two different descriptions of the same reality. My point was valid.

Slereah

"Fibre bundle formulation of nonrelativistic quantum mechanics"

HDE 226868

23:48

@JohnDuffield Ah, then in that context, you're right; it is a fair response.

Slereah

Why would I, you crazy man

HDE 226868

in Mathematics, 4 mins ago, by HDE 226868

@Jasper They inspire, not educate. That's what's needed to get more people interested in science/math/etc. You then need to spend a while correcting the mistakes, but it gets people interested, at least.

Here, "they" refers to popular science books, and the readers of said books would be kids. Any thoughts on that in here?

John Duffield

@HDE226868 : thank you.

user54412

@HDE226868 I think I agree.

ACuriousMind

@HDE226868 Um, read what I wrote, and note that the electromagnetic field is there in QFT, too. It's not that the classical field is the electromagnetic one and the quantum description is the electron one. How is that a "fair response"?

John Duffield

23:52

@HDE226868 : I think there are some dreadful popscience books. There's an awful lot of "woo" out there. Sometimes it feels like we're drowning in it. But the trouble is, woo sells. People like it. They cling to it.

0celo7

@JohnDuffield Like yours?

HDE 226868

@ACuriousMind Because you're each approaching it from a (slightly) different angle. Duffield's using a technicality - yes, an electron has electric charge, and therefore influences the electromagnetic field - while your comment was, from all other points of view, accurate. If you go with his view on a technicality, then that particular message from him was a "fair response".

John Duffield

@HDE226868 : and when you try to tell them that there's no evidence for time travel and wormholes and the many-worlds multiverse, how they howl. I've actually had conversations with religious types, including Young-Earth Creationists. There isn't much difference. They believe what's in their book, and if you show them the evidence they will find a way to dismiss it, because they think they know better, and they want to believe.

Slereah

"Evidence Against Correlations Between Nuclear Decay Rates and Earth-Sun Distance"

Where do people come up with those ideas

user54412

@Slereah dmckee linked to something about that recently

user54412

23:58

I was surprised to learn this is apparently a thing

user54412

something about neutrino-induced nuclear decay or something

ACuriousMind

@HDE226868 I completely disagree that we should lie-to-children. And it would not be that hard to make explicit in those books that they are using analogies which are not fully accurate. Yet they almost never do, and that is even worse than lying-to-children: Lying-to-children without admitting it.

user54412

^ I was expecting that ;)

Kevin Driscoll

It seems to me possible that the Dirac Spinor for the electron and the Gauge Field for the photon are actually 'two sides to the same coin' in the same way that the electric and magnetic fields both make up the Field Strength Tensor. But, I ahven't seen anyone present a precisely formulated mathematical description that makes this connection manifest.

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