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05:14
Is there really any difference between "frequentist" analysis and using Bayes's theorem?
(question inspired by this post)
user54412
@DanielSank Good question.
user54412
Given the number of papers out there that boast one or the other, you'd think there would be a difference. But I can't imagine what it is.
user54412
05:30
I mean, Bayes's theorem is trivial rearrangement of the definition of conditional probability. How could it possibly be wrong? And any notion of probability must empirically if not epistemologically agree with a frequentist interpretation.
05:42
@ChrisWhite, yeah, that's what I think too. My guess is that what's really going on is that "frequentist" and "Bayesian" comes down to different assumptions about priors.
So it's not really a difference between the methods, but rather the assumptions commonly made by practitioners of each method.
Just a guess.
user54412
seems reasonable
user54412
But it's weird -- this would be like two physicists blaming quantum interpretations for why they get different answers. "Oh, I'm a Heisenbergian, and his analysis only uses Bohmian tools.:
@ChrisWhite I see what you mean, but then again there do seem to be a higher fraction of folks who think they understand stats and don't than there are folks who think they understand Schrodinger's equation and don't.
@ChrisWhite the only person I know who I trust actually understands stats says that "frequentists" some times (often) forget that they actually are making assumptions about priors.
@ChrisWhite Well, agreement is required in the limit of a lot of data. Differences appear in when there is little data, but that is the realm where interpreting statistics gets subjective and murky anyway.
 
4 hours later…
09:25
Ugh, had a headache and went to bed early, now I'm up at 5 am.
@0celo7 with or without the headache?
@yuggib I'm fine now. Was just a migraine.
@0celo7 Hence you can enjoy the coolest hours of the day ;-) Away from, as they would say where I am now, "la canicule"
It's going to be 95+ today.
More ugh.
@0celo7 Aaaaaaaaargh horse's blood temp awfully close
(damned Farenheit)
09:41
Horse's blood temperature?
@yuggib Literally the best temperature unit.
09:54
@0celo7 100ºF is horse's blood temperature...apparently, you share the opinion on that unit with belizean people and not many more
98.6 is human blood temperature.
yes, but Fahrenheit initially used horses, not humans
Was Mr. Fahrenheit a furry?
according to wikipedia he wasn't....but maybe we should update the description to "Daniel Gabriel Fahrenheit (/ˈfærənˌhaɪt/; German: [ˈfaːʀənhait]; 24 May 1686 – 16 September 1736) was a German physicist, engineer, glass blower, and furry"
TIL "furry" is a career.
10:01
definitely is
Why on Earth is the Metal Gear Solid collection not on PC...
10:13
Looks like I have a choice to make. Either I delete my follower from the game, or start over and never get him.
Freaking Skyrim.
10:48
Too lazy to create a question on SE. What does the $u \cdot \del u$ term mean in the Navier Stokes?
That's the directional derivative of the velocity field in the direction of the velocity.
I want to say acceleration, but don't hold me to that.
> What's the difference between a wet raccoon and Donald Trump's hair? A wet raccoon doesn't have seven billion fucking dollars in the bank.
11:11
Thanks, I understand it now.
took a while
11:38
@0celo7 yes it doesn't mention such a definition
Which book?
discussing the hilbert action carroll only says that
$$T_{\mu \nu} \equiv -2 \frac 1{\sqrt{-g}} \frac{\delta S_M} {\delta g^{\mu \nu}}$$
^we now boldly define the energy momentum tensor to be
Do you know what the definition of the variational derivative is?
where the action is $S = \frac 1 {16 \pi G} S_H + S_M$
(hint: plug your equation into mine and you get it)
:P
11:42
@0celo7 yes I know it is basically the term you get after you have done the variation.
that is
$$\delta F:=\int\mathrm{d}x\,\frac{\delta F}{\delta f}\delta f$$
exactly
This is the definition of the variational derivative.
I was being trying to be lazy with $\LaTeX$
So plug you equation into mine and you see the equivalence by definition.
Maybe modulo a sign that I was too lazy to check.
11:47
@0celo7 hmm got it
@0celo7 btw your sign is wrong, I guess, plus you are missing a $\sqrt{-g}$
but thanks you saved me again :P :D
@gonenc Nope. $\mathrm{d}v:=\sqrt{-g}\mathrm{d}^4x$.
@0celo7 oh I didn't know that definition either :D
for what does the $v$ in $dv$ stand?
Fucking water closet making noises again!
@gonenc It's just notation for the canonical volume measure. Neither $\mathrm{d}$ nor $v$ have any meaning on their own.
@0celo7 stop the water flow for good, I always do that
@gonenc I mean my PC
11:54
@0celo7 nah I meant eg. in $dV$ $V$ stands for volume but I think likewise $v$ stands for "canonical volume" $dv$
@gonenc I think a mathematican would recoil in horror at this statement.
@0celo7 you mean your WC :D didn't know what wc stands for
Unrigorous 3rd worlder...
@0celo7 you perfectly write $\text dLIPS$ however right? it is the same sh*t.
@gonenc I do, with the understanding that it is nonsense :D
It's best to just write $\eta:=\sqrt{-g}\mathrm{d}x^1\wedge \cdots\wedge\mathrm{d}x^n$ and write all integrals as $\int_Mf\eta$.
11:58
@0celo7 bs! :D btw "stop the water flow" $\leftrightarrow$ "reboot your WV" :P :D
@0celo7 maybe maybe not :D
It made that "you have (dis)connected something but we won't bother telling you what" noise
@0celo7 wat? like a disconnected usb stick
yeah
@0celo7 well that is one of the reasons why we call it a WC :D
Now the fans are on full jet mode for no reason
I hit the record button
12:02
@0celo7 maybe it is because you let the windows open and the hot air flow inside
I think I was streaming YouTube
:D
@0celo7 which channel? :D
GTA 5 all endings
Some random dude
@0celo7 ^not such a good sign I guess
I forgot, my hotkeys are all the buttons I need for LaTeX
I've been taking screenshots and video this whole time!
12:04
@0celo7 what kind of hotkeys you have for $\LaTeX$
@0celo7 lol
@gonenc I mean my recording software hotkeys are the standard =\[]./
I never though I'd use them in games otherwise
I forgot to turn everything off after the stream yesterday
Shit I hit record again :D
@0celo7 does it record from the webcam or your just your screen?
@gonenc just the screen thank god
I did turn off my streaming software
Now I have to delete several GB video...1800p is a bitch
@0celo7 it shouldn't take too much time though
Done
Thankfully SSDs are crazy fast
12:14
@0celo7 indeed they are I usually see 100Mb/s
Whenever I use my old laptop to do something, that shitty RAM and 7200rpm drive are so slow.
@0celo7 gotta go, I haven't read carroll in 3 days :D
Removed?
@0celo7 I mistyped sh*t as I try to stop my bitch from barking
@ACuriousMind what kind of a person is Norbert Herrmann ie what is his personality?
12:40
@gonenc No idea, I don't know him
does anybody really know anybody :P
@ACuriousMind he is supposed to be Studien- & Prodekan
for heidelberg physics
I don't think I ever had to do with the Studiendekan. The actual current dean was my first theoretical physics lecturer, but other than that, I wouldn't know him either.
@ACuriousMind is he the right person to ask about acceptance (Zulassung) stuff?
@gonenc Yeah, that's probably what the dean of studies is there for, but I don't really know
I'm voting to close this question as off-topic because it is a duplicate of Why does the atmosphere rotate along with the earth?John Rennie 3 hours ago
^why not simply VTC as duplicate?!
Even more weird is that this isn't actually a close vote
It's the close vote text but there's no vote associated to it
12:51
@ACuriousMind thanks anyway. every one of my friends getting acceptances, and I'm the only one who hasn't got any, so I'm starting to be nervous about it. I've already written some emails to him (like a month ago about sth else) and I've received a not-so-polite email, which is why I think I'm taking too much of his time and dunno what to do now :D
@ACuriousMind maybe he taught it deserves another chance eg I sometimes wrote the exact same comment as I do for homework type of questions, but not being too sure about it I don't flag it as such
@gonenc Professor's mails rarely are overflowing with politeness in my experience ;)
@gonenc I could understand that for other types of question, but not for a duplicate
Also, leaving the text "I'm voting to close" without actually voting to close is plain weird.
@ACuriousMind I mean in his second email, no greeting, no whatnot just "at the latest beginning of august" implied for me "go away I've got work to do"
@ACuriousMind that is indeed weird though
@gonenc Okay, that's a bit rude (but since I don't know him this could well be normal)
@ACuriousMind I think I'll just wait a few more days and then (if I have the courage :D) I'll write an email.
13:06
@gonenc You can take comfort in the fact that he's unlikely to give any of your lectures ;P
@ACuriousMind I dearly hope that... :D :D
13:49
is there a flag reason for insufficient prior research?
Nope, you'll have to choose custom for that (also, I don't think we really have consensus whether such question should be closed, but it seems a slight majority does it)
14:03
@ACuriousMind should we put it on meta?
I mean take a look at this
0
Q: What velocity do I need to get the moons orbit perfectly aligned with the earths center

Andrew WilsonI have a simulation for universal gravity with two objects. How can I calculate the velocity or instantaneous force I would need to apply to object 2 (the moon) to get it to orbit so that the origin of the moons path around object 1 (the earth) is at the origin of the earth. NOTE: The moon is al...

especially the comments
@gonenc It is on meta. Multiple times, look at the links therein.
@ACuriousMind I see...
@ACuriousMind a lot of people think questions should be closed for showing insufficient prior research, but I'm not one of them. I favor simply downvoting. But I'm close to the fence.
@DavidZ In the abstract, I'm against closing them. When I see the specific instances, however, I often find myself thinking we shouldn't have such questions.
Well, a lot of them are closable for other reasons as well.
But I understand your feeling. I think the same way sometimes.
The reason I haven't flip-flopped in favor of closing such questions is the difficulty of determining what constitutes sufficient prior research and whether the OP has actually done it.
14:19
I think the entire question should be looked at first.
@DavidZ checking the wiki page, or the first few pages of a google search may suffice to define sufficient prior research
24
Q: What counts as sufficient prior research when asking a question?

David ZOn Physics Stack Exchange, people asking questions are expected to demonstrate that they've put a certain amount of effort into answering the question themselves. What exactly counts as sufficient effort?

Even with that definition there's still the matter of how to definitively tell when an OP hasn't done enough
And then there's the issue that this shouldn't be about OP at all :P
@DavidZ then I don't see any problem determining whether OP showed sufficient effort, because if his answer is in a wiki page, then it is obvious that he didn't do enough research
It's questions we close, not users
14:22
@gonenc right, those are the easy cases. But the debates are never decided by the easy cases.
@DavidZ can't we say that the easy cases are the only cases that we close.
Keep in mind that they are asking a bunch of people to volunteer their time to answer...
then the question becomes, where do you draw the line between easy and hard?
I mean what is newtons's first axiom is kind of a dumb/dull question to ask
@DavidZ as I've said wiki pages, first entries in google search etc. eg it is not an obvious insufficient research if the question phrased by OP has an answer in a 600 page book.
14:55
What about Hyperphysics? Or if the answer is on Space Exploration or Chemistry? Seventh result on Google? Or top result with an unusual choice of search term?
@DavidZ I see the problem but what I'm trying to say is this: we can set a line, which may be somewhat blur, but we may do that if the community agrees to it, which I highly doubt
15:18
That is part of the issue, that different people have different opinions
15:34
> Once we start judging some questions as insufficient research, some users will inevitably start using that reason as a bludgeon to suppress questions they don't like. And how do we determine where the cutoff is? How is it fair for anyone to decide that a certain level represents the cutoff of too little prior research
@ACuriousMind Do you know what the "disable" command in Skyrim does exactly? I need to delete a follower that's bugging out.
@0celo7 are you streaming later?
@FenderLesPaul Maybe.
Holy crap, the hard drive noises on this laptop freaked me out!
@FenderLesPaul I need to figure out the mic situation.
@0celo7 Dunno
15:50
@0celo7 oh ok, cool
Streaming GTA5 right now.
@FenderLesPaul I need you to tell me what the mic sounds like.
@0celo7 alrighty
Louder? Quieter?
I'm getting feedback, not good.
Oh lol I didn't mute my second monitor.
@0celo7 I don't hear the mic at all actually
btw I'm letting time pass in game
15:53
@0celo7 nvm I can hear it now
@0celo7 the volume is fine
@0celo7 dude you're like 3 years younger than me and your voice is deeper :(
I can't grow a beard :(
and yeah I hear SE and the mic so I keep hearing things twice
Is there any static?
I have a theory
no static
Can you hear my clacking?
15:54
clacking?
keys
oh yeah
and I hear the annoying chat notification sound too
Alright I have to adjust the mic sensitivity
No idea where those are coming from
and I hear what you say twice, akin to an echo
exactly
15:56
brb 15 mins, gotta shower
cya
You were hearing me twice because I had an unmuted stream coming in through the background.
My broadcast program records everything coming through the jack, not just the game.
@KyleKanos Any reason you wrote that as a citation but didn't say who it was from?
@ACuriousMind Laziness? It's from Jim's answer to the Meta post that you linked
16:11
@FenderLesPaul I bumped up the microphone sensitivity by a few db. It should now be sensitive enough to capture my voice but ignore the keyboard. However, if I'm typing while talking you should be able to hear the typing.
That can't bemore exciting than watching Skyrim bug out
yes it absolutely can
nah
It'll get more exciting in about 1.75 hours because it'll be the actual championship match. They've got the Top 8 in a double-elimination match up
16:22
@0celo7 alrighty lemme check it out
I like the clacking of the keyboard haha it's relaxing
I take it you can't hear me?
oh sorry I replied in the twitch chat
I can hear you but not that well because of the game music
17:15
@0celo7 hey dude I'm back but I have singing lessons from 2:15 to 3:15 so if you're streaming after that I
I'd be totally down to watch*
@FenderLesPaul you watching now? I'll play the game, but no use streaming if you're not
18:08
Any of you guys know places that allow one to do 2 masters at the same time?
I know UvA does erasmusmagazine.nl/international/detail/article/… and it has an okay mathematical/theoretical physics masters
@bolbteppa You may be interested in this quora post: quora.com/Can-you-do-two-masters-degrees-at-once
Random civil war battle from Immersive Patrols.
19:04
@Danu I know. But $dr^2 + r^2 d\theta^2$ is a scalar quantity by definition, it is not a metric tensor, let alone a tensor in any sense of the word. — Dr. Ikjyot Singh Kohli 1 min ago
Sigh...
What does he think those $\mathrm{d}$s are?!
@ACuriousMind infinitesimal lengths :D
woops, caps
@ACuriousMind $\ll 1$
@0celo7 :)
@ACuriousMind short-hand for delicious
19:06
Not a tensor in any sense of the word, haha
@Danu caps suited that, somehow
@KyleKanos uh
@KyleKanos Ah, that makes sense!
@Danu Wait...he's a PhD?
@0celo7 Hence the Dr bit
19:07
I'd expect that from an undergraduate.
@Danu Didn't @Jimself say this guy once chewed him out for some imprecise terminology on manifolds?
That's short for Doctor, not Drool
@0celo7 Don't think so, lol
@ACuriousMind Lmao
@Danu @Jimself claims to know him.
@0celo7 Oh god hahaha
I don't see how he could make such an elementary mistake, then
19:08
I think this is relevant:
4
Q: Is a metric tensor field the same thing as $ds² = -dt² + dx²+ dy² + dz²$?

Stan ShunpikeI am having trouble understanding the nature of the metric tensor field on spacetime manifolds. In particular, a Riemannian manifold $(M,g)$ is defined as a real smooth manifold $M$ equipped with an inner product $g_p$ on the tangent space $T_pM$ at each point $p$ that varies smoothly from poin...

@ACuriousMind does this look as interesting to you as it does to me?
@Danu Why, yes, it does :D
:D :D :D It's on my reading list
So yeah, the guy does actually have a PhD
but mmmm, this puzzles me greatly then
@Danu Wrong.
@Danu I believe that he does.
19:14
@0celo7 ?
He's at York
Wrong. Tensors with indices such as the ones one is used to from e.g. general relativity are not really tensors, they're just tensor components. The object $g$ in my expression is the tensor, and its expression in terms of coordinates is nothing but one manifestation of the coordinate-independent object. — Danu 11 mins ago
Wrong
@0celo7 What? Me?
Just like that wording
19:15
Ah
It's strange that someone who apparently really knows some serious mathematics would make a mistake that I can correct!
I could correct it.
My cat could correct it.
Now hold up a sec... ;) (jk)
But your cat is Einstein.
that's no surprise ;)
I'm not sure how good Einstein's understanding of diffgeo was
Was about to say "So, Einstein was pretty smart"
19:17
@Danu Well, hsm is yours, not mine ;)
@ACuriousMind It's all MIIIIINE
. . . and mine. By the way, @Danu, if you're right, then Einstein struggled a bit at first.
@HDE226868 Oh, I know that much for sure ;)
@ACuriousMind Not playing PoE?
Well, the conversation with Dr. Kohli took a turn for the best so it's all fine :)
19:30
"Mathematical physicist"
Is he even elite?
Well, I wouldn't even call myself a physicist at all
I see 3 people are watching my stream. Anyone from here?
Now, yes
@0celo7 Soon. I do having finishing touches to make on my simulation and my notes for my talk.
19:54
@0celo7 hey dude I'm back from my lesson, sorry about that; hope you saw my message before I left
That MKX finale was amazing, BTW
@FenderLesPaul He's streaming right now
@Danu oh cool, thanks for the heads up :)
@KyleKanos I'm sure it was
@FenderLesPaul any particular questline you want me to start?
@0celo7 I'm cool with anything really
god the music is so relaxing
what sword is that? it looks sick
if you dual wield that it would look so awesome
@0celo7 wait did you say message here or on twich?
alrighty
20:03
I turned off the mic because people are walking around me
are you at a library or something?
no, at home
talking to myself when alone is fine ;)
so much money...
dude wtf those swords are ridiculously huge lmfao
20:07
I know
In a moment I'm going to delete Gorr from the game
He's too bugged out that when I try to patch him, the game crashes
he's also kind of a dick
and Eorlund is bugged out and won't sell me anything
@FenderLesPaul just selling some stuff
Will get to adventuring soon
alrighty
I'm waiting on my insomnia cookies anyways haha
@FenderLesPaul How much have you played this game? I could do some quests you haven't seen before
ooooh treasure maps!
@0celo7 not much at all, most of time was sunk into Oblivion, so chances are it would be a quest I haven't seen
20:15
I know exactly where this treasure is
or...not
actually, do you mind if we go on twitch? that way I can keep an eye on how much delay there is
 
1 hour later…
21:38
@ACuriousMind The Falskaar quest mod is pretty amazing.
It adds an island bigger than Solstheim, fully voice acted.
Probably not lore friendly, but who cares?!
user54412
"Probably not lore friendly, but who cares?!" -- kids, this is your brain on GTA.
@ChrisWhite You're welcome to join the stream.
It's not lore unfriendly really.
21:57
in Mos Eisley, yesterday, by Richard
→ → → → → This way to the Special Secret Chatroom
Join this^ stream.
:D
user54412
22:10
Clicking on obfuscated links is like injecting with a needle found in a crack den -- sure, it might turn out to be fun, but more likely you'll regret it.
3
Speaking from experience? But well said.
I've never been in a crack den that wasn't great fun.
@0celo7 Me neither :)
@ACuriousMind See, @ChrisWhite. You need to come to some DC or Heidelberg crack dens. Jersey crack dens give the whole crack den community a bad name!
Oi this fuck wants 500 gold to take me back to Skyrim!
@FenderLesPaul Going to eat dinner, don't know if I'll be on later.
I now have 26GB Skyrim stream videos.
22:28
Later pal
1
Q: Why is this handle flipping back and forth?

Tom MedleyThis gif of some kind of handle being spun in zero gravity has been doing the rounds: Why is it flipping back and forth? It seems odd that it flips, then seems to rotate around one axis in a reasonably stable manner before suddenly flipping about entirely.

I know this is a duplicate, but I cannot find the original
Found it for you
31
Q: Why does this object periodically turn itself?

pacóSee this video about 30 sec in. http://www.youtube.com/watch?v=dL6Pt1O_gSE Is this a real effect? Why does it seem to turn periodically? Can it be explained by classical mechanics alone? Is there a simple equation that models this behaviour?

@KyleKanos You're a wizard.
Nice work.
Wizard
:-)
???
22:42
I'm surprised this never got an answer. Anyone have an idea?
I'm convinced there's a bot that stars everything @DanielSank says with a link in it...
@0celo7 it does seem that way.
Awwww, it got removed.
aaaand it's back.
I'm convinced there's a bot that unstars everything @DanielSank says with a link in it...
^ LOL
Bot, identify yourself.
@KyleKanos Nice google-fu there ;)
22:47
@ACuriousMind Look up something about tops.
Oh, Kyle found it.
@0celo7 aw ok
I'll be here if you do, just finished my food
I'll mess around on my guitar in the meantime
Electric?
@KyleKanos It's disappointing that the answer doesn't answer the question, but is rather a list of references.
Do'mt we normally close those?
@skillpatrol I play electric and acoustic; right now acoustic because I'm trying to learn how to sing April Come She Will
22:51
yerp
Although there's this post I've been meaning to answer but keep lazing out :p
@FenderLesPaul Holy crap, the other quest mod I have adds a whole other island too!
@DanielSank Agreed. It should have a better answer than that.
@DanielSank You mean delete? Yes.
@0celo7 whaaat dude that's insane
god I hope it has better voice acting
You're complaining about that voice acting after being addicted to Oblivion?
That game's voice acting makes me chuckle it's so bad.
23:06
I mean Oblivion had terrible voice acting but none of the female characters had pitches that humans should otherwise not be able to reach
Dude do you know the game 2worlds?
nope
it was basically an oblivion clone back in the day and it had such hilariously bad voice acting I almost had a stroke when i first played it
such a German name
"Forsooth"
that coupled with Monty Python quotes within the game and you got yourself a game so bad it's good
watching this vid
will stream right after
I have to witness this new island with me own eyes
I bet you haven't seen Solstheim in Skyrim, have you?
@FenderLesPaul lol
23:16
@0celo7 I have not
@FenderLesPaul there's a third new island for you then
Only this one has Skyrim voice acting
oh yay
sonorous and novel, what more can I ask for? :)
@FenderLesPaul Setting up!
check el twitcho
23:33
@KyleKanos you don't follow Smash Bros' Melee, do you?
23:54
0
Q: How can we encourage our users to answer physics oriented math questions on Math.SE?

DanielSankThere's always been a bit of fuzz around the issue of on-topic-ness of math (and engineering, but that's a discussion for another day) type questions on our site. Many questions which are in content strictly mathematical would best be answered by a physicist because either the math topic is known...


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