The h Bar

0celo7

7:00 PM

@JohnDuffield What about tilted spacetime?

John Duffield

@0celo7 : look at my avatar.

0celo7

What?

Secret

Hitler's face looks like he's being smacked by a pan face on

0celo7

What?

John Duffield

@Secret : I watched a documentary on Hitler last week. What a delusional nutjob. How on Earth the German people thought he was some kind of messiah absolutely beats me.

bolbteppa

7:02 PM

Liking how Trump is on that page :p

Secret

Well, national identity blahblahblah stuff that I am nto bothered to think about, that's why

bolbteppa

After watching this election I am no longer surprised by the mass hysteria that went on back then

John Duffield

If I could vote I'd vote for Trump. I saw Clinton lying about Farage. And we all saw what she really thinks of ordinary Americans when she was addressed that LGBT event last week. A basket of deplorables. FFS.

Anyway, does anybody know how many photons 2S positronium decays to?

0celo7

@bolbteppa Sigh, why did I unblock you? How can people compare this election to "let's take over Europe"

bolbteppa

None of that surprises me at all

@0celo7 why do you keep talking to me about blocking me, go ahead

@JohnDuffield ordinary Americans don't support someone tearing up the foundational document of their country

John Duffield

7:11 PM

I voted for Brexit.

@bolbteppa : can you give me a reference for that?

And does anybody know how many photons 2S positronium decays to?

0celo7

@JohnDuffield My proof is fine, I don't know what your complaint is.

John Duffield

@0celo7 : check your axioms.

0celo7

what axioms?

bolbteppa

@JohnDuffield dailywire.com/news/4058/… theguardian.com/us-news/video/2015/dec/08/…

John Duffield

Sigh.

0celo7

7:15 PM

@JohnDuffield no clue what you're talking about.

bolbteppa

@JohnDuffield you voted for the biggest mistake a country has made in a generation, now that science funding is under a huge question mark I'm sure more people will get into the whole alternative science thing though, happy days right

Obliv

Guys, Something is wrong.

0celo7

Sigh, what?

Aha!

Figured out my issue.

John Duffield

@bolbteppa : Trump's stance on Islamic terrorism is not "tearing up the foundational document of their country". Instead Clinton's open-door immigration policy (hoping to get their votes) is an act of betrayal. We've had all that in the UK with the Labour party. And no, UK science funding is not under threat because of Brexit.

0celo7

@Obliv help me with my shelf pls

@JohnRennie can you link me wormrot pls

I want to listen to it again

maybe third time's the charm

John Duffield

7:21 PM

@0celo7 : oh yes I do. Remember, when it comes to gravity, I'm the expert. Spacetime curvature is associated with the tidal force, not the force of gravity.

0celo7

@JohnDuffield Sigh. My proof has nothing to do with gravity.

And don't pretend you know more Riemannian geometry than me.

You'll embarrass yourself.

John Duffield

@0celo7 : I do so. That's the thing. It isn't me embarrassing myself.

0celo7

You know more Riemannian geometry than me?

John Duffield

@bolbteppa : re UK science funding see Nature : UK government gives Brexit science funding guarantee

@0celo7 : Yep. Sigh. Where's this proof then? I'll shoot it down for you.

0celo7

I made a slight change earlier.

bolbteppa

7:26 PM

Everything has so many flaws, ok lets stop this, Brexit was so wonderful all the universities dropping in the rankings was going to happen anyway, this nature.com/news/… shows it was better off to leave, up is down, black is white, etc...

Obliv

@0celo7 nevermind

Keep pushing more books into it, I'm sure they'll fit.

That or stop hoarding books nerd

John Duffield

@0celo7 : your problem is in your first line, in your lemma. Small enough means infinitesimal. It isn't a ball, it's a speck.

0celo7

Haha.

You're funny.

DanielSank

@JohnDuffield I am, oddly, not surprised.

3

0celo7

@JohnDuffield You're not on Trump's level. Give it up.

Your act got old months ago.

DanielSank

7:31 PM

@JohnDuffield losing a world war and being impoverished helps.

John Duffield

@bolbteppa : trust me, the UK is better off not being shackled to an unaccountable oligarchy who cook up cosy crooked deals so that global giants don't pay tax, who condemn Greece and other countries to poverty, and who sneer at democracy as mere populism.

bolbteppa

omfg

DanielSank

@Obliv good grief. You need better tea.

bolbteppa

Apparently there is more democracy in the EU in terms of countries unanimously passing laws together and needing over 60% on certain things (iirc) than there is in most of the separate countries, but they are also unaccountable oligarchs, because up is down and black is white

DanielSank

@JohnDuffield again, not surprised: your discourse on politics has a similar tone and structure as your discourse on science.

John Duffield

7:36 PM

@DanielSank : it's difficult to say why Germany embraced Hitler. I don't think it was anything to do with being impoverished.

bolbteppa

Oh my god it makes so much sense all these views are tied up with calling a ball a speck and being deadly serious

John Duffield

@DanielSank : I believe in democracy. I treasure it.

@bolbteppa : where are you getting this propaganda from? Europe has three presidents, and you can't vote any of them out of office. Compare and contrast with the USA.

0celo7

@Loong Meanie.

John Duffield

@bolbteppa : I'm serious. Read what Einstein said. See the second paragraph where he said valid in the infinitesimal. That means valid in a region of infinitesimal size. In a region of no extent. In no region.

bolbteppa

lol

0celo7

7:41 PM

Oh my god are you serious

Stop quoting that crackpot physicist

You don't know any mathematics beyond algebra 1

John Duffield

@bolbteppa : LOL yourself. See where Einstein said the theory of special relativity, therefore, applies only to a limiting case that is nowhere precisely realized in the real world. It's the same for 0celo7's proof.

0celo7

Who said anything about special relativity?

bolbteppa

'It's the same for his proof' (lol)

0celo7

You know nothing about serious mathematics.

John Duffield

@0celo7 : Einstein wasn't a crackpot physicist. Your proof fell at the first hurdle.

bolbteppa

7:43 PM

Oh my god, that is honestly so funny

0celo7

@JohnDuffield Nope.

John Duffield

@0celo7 : yes. I told you to check your axioms.

DanielSank

@JohnDuffield People are a lot less likely to want to fight a war if they have everything they need, duder.

@JohnDuffield You're pulling our collective leg, right?

@0celo7 HAHAHAHA called Einstein a crackpot physicist. Nice.

arda

Please respect each other in chat. Kindly pointing out the mistakes instead of saying "you know nothing" would be better for both you and the other user.

DanielSank

Also note the existence of the "ignore user" feature.

Obliv

7:47 PM

damn what the hell is going on in here

arda

+1. Flag validator off o/

DanielSank

@arda wut?

arda

It was flagged

John Duffield

@DanielSank : I reject that as a reason for Germans embracing Hitler and his plans for conquest. The German people weren't poor in 1914. It was La Belle Époque.

Obliv

JD is arguing about the use of the word infinitesimal in a math proof? is this seriously happening

arda

7:48 PM

It was a valid flag.

Obliv

math isn't meant to conform to the real world..

DanielSank

@arda "Flag validator off"? Also what's the +1?

John Duffield

@DanielSank : no, I'm not pulling your leg. Einstein said SR is nowhere precisely realized in the real world.

bolbteppa

I think he used Einstein saying SR is only infinitesimally realizable in the real world due to gravitational fields as proof the idea of infinitesimals do not exist, but they also prove a theorem about geodesic balls, not sure exactly

arda

I validated the flag (so did 4 other people). And I'm off this room. +1 is for ignore user.

Obliv

7:49 PM

@daniel Flag validator off means the person is calling themselves a flag validator (possibly jokingly) then saying that they are leaving. +1 refers to agreeing with the post above.

DanielSank

@Obliv Got it.

@arda Got it.

Obliv

Yeah @0celo7 is getting really salty. more than usual 8^)

did he get timed out?

DanielSank

'Ignore user' has saved me from breaking the "be nice" policy many times.

2

Obliv

if you got timed out @0celo7 don't say anything.

bolbteppa

I think he is tamer than usual tbh :p

DanielSank

7:51 PM

@JohnDuffield Are you perhaps taking the written word too seriously, and a reasonable understanding of calculus not seriously enough?

John Duffield

@Obliv : yes. read this : arxiv.org/abs/physics/0204044

See page 20 : "If so, it is false. In Einstein’s theory, either there is a gravitational field or there is none, according as the Riemann tensor does not or does vanish".

bolbteppa

@JohnDuffield I mean really, you took a random sentence on special relativity and took it as a statement about infinitesimals and specks, it's like reading the sentence "the big dog" and thinking the sentence is talking about Big Ben because of the word big

DanielSank

^Agreed

John Duffield

@bolbteppa : no it isn't.

DanielSank

And @JohnDuffield, you do this all the time. Any chance you'll give it up?

2

John Duffield

7:53 PM

@DanielSank : I'm just talking physics. I won't be giving that up.

bolbteppa

Ok please clarify why you quoted that passage and said it was a proof of the theorem quoted above on geodesic balls, with reference to specks if possible (mandatory)

DanielSank

@JohnDuffield ok. I think I'll take my own advice and use the "ignore user" feature for a while, because I don't think I want to see the conversation that's going to take place here for the next ten minutes.

'sup @Obliv?

Hey who's @HelkaHomba? New user?

Oh, nope.

bolbteppa

Wait, did he do it again?

Did he quote Einstein's field equations and Riemann tensors to question the idea of infinesimals LOL???

John Duffield

@bolbteppa : see what I quoted above (by Synge) about "the Riemann tensor does or does not vanish". It doesn't. And yet 0celo7's proof says if the Riemann tensor vanishes. It doesn't. Not until your ball is of infinitesimal extent. Of no extent.

bolbteppa

Oh my god, that is absolutely amazing

@JohnDuffield in baby calculus, there is a topic you study called limits, try answering exercises like $\lim_{x \rightarrow 2} x^2$ by quoting Synge, you should check out those sections

John Duffield

7:58 PM

@bolbteppa : what's really amazing is that the Principle of Equivalence only applies ot a region of zero extent too. Read the rest of the Synge quote:

"The Principle of Equivalence performed the essential office of midwife at the birth of general relativity, but, as Einstein remarked, the infant would never have gone beyond its long clothes had it not been for Minkowski’s concept [of space-time geometry]. I suggest that the midwife be buried with appropriate honours and the facts of absolute space-time faced."

Obliv

not much @daniel procrastinating on doing a lab report. The usual.

John Duffield

So, can anybody tell me how many photons you get when 2S positronium decays?

@DanielSank : it's just physics.

user218912

hi

Obliv

yo 3075 or @icelord as you now prefer

Danu

@DanielSank o/

You know, you keep on falling into that trap we talked about :P

user218912

8:14 PM

@Obliv what classes do you have this term?

Obliv

@icelord physics 3, calc 3 and some gen eds which I must painfully endure :[

user218912

only 2 math/physics courses? D:

Obliv

yea I have to take these stupid general education courses so no room

0celo7

If you think they're stupid they only get more painful.

Obliv

welcome back @0celo7

0celo7

8:18 PM

@JohnDuffield I don't know where I said anything about infinitesimals.

user218912

@Obliv why though?

0celo7

The fact that you think I did shows you've never taken an analysis or topology course in your life.

user218912

I only have to take 1 non physics elective.

0celo7

@DanielSank From the crap I've seen JD post from the Einstein digital papers, I've concluded Einstein was a crackpot.

5

John Duffield

@0celo7 : you didn't. I did.

@0celo7 : he isn't.

0celo7

8:20 PM

If you write any of that stuff and your name isn't Einstein, you'd get laughed out of the room.

Obliv

@icelord different schools, different circumstances, etc.

bolbteppa

@JohnDuffield what "and the facts of absolute space-time faced" should we face? (lol)

John Duffield

@0celo7 : if you see something Einstein wrote that is contradicted by something in your textbook and there's no explanation as to why, you should look closely at it.

0celo7

Sigh. You've ruined Einstein for me.

user218912

lol

John Duffield

8:23 PM

@bolbteppa : space is real, not some abstract nothing thing.

Danu

@JohnDuffield Hitler was "elected" (or rather "took over") in the early thirties. Looking at the popularity of his party, it is really quite obvious what the rise in popularity corresponded to:

John Duffield

@0celo7 : I've probably ruined Hawking and Ellis for you.

Danu

Picture coming up... [slow internet connection ATM]

John Duffield

@Danu : what? Germany wasn't starving.

Danu

Right after a big economic breakdown the popularity soared. Before that it was very low, consistently so.

An eight-fold increase in votes in the first election after the crisis is pretty clear, no?

John Duffield

8:26 PM

But we didn't elect a Hitler in the UK. Did we?

Or start invading other countries.

Obliv

oh yeah @0celo7 my textbook said something like "amedeo avogadro ... who suggested that all gases occupying the same volume under the same conditions of temperature and pressure contain the same number of atoms or molecules."

that suggestion was wrong right?

Balarka Sen

Why are we having a parallel discussion slash fistfight on both Hitler and infinitisimal Riemannian balls?

John Duffield

I don't know. I'm going to stop talking about Hitler. Because it could end badly.

Balarka Sen

That's like a Lynch movie: you can never ever understand what the hell the conversation is about because of so many parallel plots

Danu

@JohnDuffield I wasn't reacting to that.

John Duffield

8:28 PM

@Danu : to what?

Danu

@JohnDuffield It's just important that you understand what the cause of the rise of Hitler's party was, and not get your historical facts wrong (how could you even think Hitler was in power in 1914?!?!?!?! That's seriously off!)

0celo7

@BalarkaSen NOTHING INFINITESIMAL

Danu

@JohnDuffield To anything UK-related.

0celo7

Epsilon positive does not mean infinitesimal holy crap

bolbteppa

haha

Balarka Sen

8:29 PM

I am aware, @0celo7.

Obliv

@balarka want to try solving a problem that I couldn't even come close to solving in 50 minutes of thinking? it'll probably waste your time 8^)

Balarka Sen

@Obliv Nope.

user218912

Jul 16 at 22:09, by ACuriousMind

Seems we're comparatively Hitler-free here

user218912

dammit guys you're ruining it

0celo7

@Obliv why would he

bolbteppa

8:30 PM

1914 is as close to the truth as a speck is to a geodesic ball I'm thinking

John Duffield

@Danu : I didn't say Hitler was in power in 1914. Now that's enough on Germany.

Obliv

I thought that was what mathematicians were into

DanielSank

@Danu \o

Which trap?

Danu

42 mins ago, by John Duffield

@DanielSank : I reject that as a reason for Germans embracing Hitler and his plans for conquest. The German people weren't poor in 1914. It was La Belle Époque.

But you did @JohnDuffield

@DanielSank Ignore feature

DanielSank

Ignore feature is a trap?

John Duffield

8:31 PM

@Danu : read it again.

Danu

@DanielSank Turning it off is

Obliv

I'll put it here because I want others to suffer. Let $A$ and $B$ be positive integers such that $ab+1$ divides $a^2 + b^2$. Show that $\frac{a^2+b^2}{ab+1}$ is a square of an integer.

bolbteppa

1933 is a liberal media conspiracy by the globalists

DanielSank

@JohnDuffield I'm sorry... you think the UK never invaded other countries?

Obliv

it's from a 1988 math olympics that only 11 out of 200+ people solved. Found it from a video related to the one secret posted yesterday on numberphile

Balarka Sen

8:32 PM

@Obliv The standard technique is Vieta jumping.

Obliv

how did you know! :O

Danu

@DanielSank THE TRAP

Balarka Sen

googled it once. I have another way to do it which I prefer over that but it's tedious

Obliv

but vieta jumping looks so much simpler..

DanielSank

@Danu Couldn't help it. I was looking at my inbox and when you see the chat log that way the users I have on ignore are still shown.

Danu

8:34 PM

@Obliv 1988? Damn, I was hoping this one prof of mine who was epic at Olympiads would've done it

He was 5 years earlier :(

@DanielSank 'tis alright

DanielSank

Also, Europeans making ridiculous statements about their own culture and history is one of my favorite pet peeves ;)

Obliv

@danu math olympiads are damn impressive honestly. How old are the contestants usually?

John Duffield

@DanielSank : no more on Hitler and Germany. Zippp. My mouth. Shut.

DanielSank

A Brit suggesting for a microsecond that the UK didn't go about the planet invading other countries is just too good to be true.

Danu

@Obliv High school, that's the point :P

DanielSank

8:36 PM

Clearly whoever makes such a statement hasn't watched Eddie Izzard's bit about flags.

Do you have a flag? - Eddie Izzard

►

Obliv

@0celo7 so do you know?

DanielSank

@JohnDuffield you may also wish to refer to the little parable of how Britain stole Arabia from the Arabs.

They made a move about it... oh what was the name...

It was famous...

Lawrence of Arabia (film)

Lawrence of Arabia is a 1962 epic historical drama film based on the life of T. E. Lawrence. It was directed by David Lean and produced by Sam Spiegel through his British company Horizon Pictures, with the screenplay by Robert Bolt and Michael Wilson. The film stars Peter O'Toole in the title role. It is widely considered one of the greatest and most influential films in the history of cinema. The dramatic score by Maurice Jarre and the Super Panavision 70 cinematography by Freddie Young are also highly acclaimed. The film was nominated for ten Oscars at the 35th Academy Awards in 1963; it won...

John Duffield

Anybody: is there a name for any "law" which describes the magnetic force between two charged particles? As per this answer, the Biot-Savart law doesn't seem to be it.

DanielSank

Yes! That's the one.

@JohnDuffield It's the electromagnetic force.

::awaits endless internet karma::

8:40 PM

Come on, that was the funniest thing I've ever typed around here.

John Duffield

@DanielSank : there's one field and two forces. See Minkoski's space and time, near figure 3. "In the description of the field caused by the electron itself, then it will appear that the division of the field into electric and magnetic forces is a relative one with respect to the time-axis assumed; the two forces considered together can most vividly be described by a certain analogy to the force-screw in mechanics..."

1 min ago, by Danu

LOL

@DanielSank : electromagnetic field interactions particles results in linear electric force and/or rotational magnetic force.

DanielSank

Oh I give up.

Danu

8:44 PM

2 mins ago, by Danu

1 min ago, by Danu

Ba Dum Tss!

►

Balarka Sen

dancing banana would be appropriate here :P

John Duffield

Does anybody know of a simpler version of this, perhaps with only one velocity?

$\vec{F}=\frac{\mu_0}{4\pi}\frac{q_1 q_2}{r^2}\vec{v}_1\times (\vec{v}_2\times\hat{r})$

bolbteppa

Let me quote Einstein here, who once said, $2 + 2 = $ the number of extensions in space a force-screw can turn, if you will, that being the number pointing north when a clock on the southern hemisphere is oriented in the direction that moss grows in springtime, indubitably being the number of fingers strike one on the hand of Alexander leading his golden chariot to victory, in other words, $2 + 2 = 4$

4

Come on man

John Duffield

@bolbteppa : huh? See Maxwell’s On Physical Lines of Force: "a motion of translation along an axis cannot produce a rotation about that axis unless it meets with some special mechanism, like that of a screw".

Bernard Meurer

addictionsandrecovery.org/cocaine.htm

Y'all gotta stop smoking crack

bolbteppa

8:52 PM

The only way I can answer that is a chapter from Shakespeare at this stage

Bernard Meurer

@JohnDuffield Are you blond?

John Duffield

@bolbteppa : you'd be better off doing some physics research. Like into the right hand rule.

See Wikipedia and look at the caption for the picture above.

Danu

I think I need to do some research on the right hand, if you know what I mean ^^

Bernard Meurer

@Danu What if he's left-handed?

John Duffield

@BernardMeurer : no, brown-haired balding and greying.

bolbteppa

8:56 PM

@JohnDuffield I thought you believed in 4-D spacetime, yet now you're telling me to believe 3-D rules like right hand rules, what gives?

Bernard Meurer

John Duffield - 1 OF 6

►

Seems like a fit

John Duffield

@bolbteppa : I don't "believe" in 4D spacetime. We live in a world of space and motion. The map works, but the map is not the territory.

bolbteppa

I have much to learn it seems

John Duffield

@bolbteppa : it seems you do.

Obliv

@bernard hey man

Bernard Meurer

9:00 PM

@Obliv Howdy

Obliv

how's things in uni? You moved in yet?

Bernard Meurer

Yeah man, just moved to Lisbon this week

Classes start on the 19th, I'm excited

John Duffield

Nice city Lisbon.

Bernard Meurer

@JohnDuffield I like your blazer

Yeah, I really like the city

Physics Meta

0

Q: Hot Network Question titles are interpreted as LaTeX / MathJax?

I noticed when viewing a question here that a hot network question from Money.SE was formatted strangely. Presumably because it's interpreting the title as math markup. Screenshot from this site: Screenshot from another site:

Obliv

9:06 PM

@JohnDuffield that's been bugging me for a while too, actually. If we define time to be relative local motion, then it's not really there in actuality. It's just a construction that we use to make things easier and feasible.

Not believing in $4D$ spacetime is like not believing in virtual particles. It doesn't matter whether or not you believe in it. Whether or not it's real, it works in accurately portraying physical phenomena. I think.

Bernard Meurer

@Obliv You're right

@JohnDuffield You're an IT guy?

John Duffield

@Obliv : it's the same for heat. Heat is an emergent phenomenon. But it is really there, as you will appreciate when you put your hand on a stove. Szzzzt! And get this: a hundred years will kill you just as surely as a hundred degrees C.

@Obliv : it does. But we live in a world of space and motion, not some static block universe.

Obliv

@JohnDuffield Wait what do you mean by this? Are you trying to say time kills you?

John Duffield

@BernardMeurer : yes. I've always been into physics, but I started taking a special interest about ten years back when our then-teenage children gave up all their science subjects and I found out that UK physics A-levels were down 57% in 20years. It was like I was witnessing the death of physics. And I said to myself: not on my watch.

bolbteppa

and an electron is a photon in a trivial knot

Around 11.00

I think quoting 1850's papers is the next level above quoting buzzwords tbh

John Duffield

9:16 PM

There's some good stuff in those old papers.

bolbteppa

So you decided to throw away the A levels books and do physics with no math, as opposed to the algebra-based physics they probably did

John Duffield

@bolbteppa : huh? I didn't. What I decided to do was understand what the mathematical terms meant. Things like c and E and m and C.

Hence I understand what Einstein was saying in his E=mc² paper.

OK I've got to go. Nice talking to you. Bye.

bolbteppa

@JohnDuffield and the result of that is saying things like 'and an electron is a photon in a trivial knot', I defy anybody to explain that one, why do you think the people who've studied the theories (+ math) don't say things like this, just as a general observation?

Slereah

9:31 PM

6

Manolis Lyviakis

10:17 PM

any1 here?

0celo7

10:42 PM

Nope

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