« first day (2686 days earlier)      last day (2226 days later) » 
00:00 - 17:0017:00 - 00:00

Anonymous
5:00 PM
Yeah, it seems he had made some very weird assumptions and theories to explain refraction and diffraction. I found a textbook which says: "Newton assumed that when a light corpuscle comes within a very small limiting distance from the refracting surface, it begins to experience a force of attraction towards the surface"
 
Anonymous
Except this time the force of attraction wasn't "gravity"! :P
 
Slereah
Slereah
Pretty hard to make a classical theory of light
 
Anonymous
He developed some non-trivial geometry results in the process though
 
Slereah
Slereah
Geometry was the cool thing to do back then
Using coordinates was a new thing!
 
Physics Meta
Physics Meta
-1
Q: Should we curate a "bogus science" wiki or similar?

thanbyA recent answer and subsequent comment discussion revealed there are possibly many bogus science sources on the web that are apparently invading the SE network. I understand that downvoting plays a key role in keeping this kind of information in check, but it seem like it might be beneficial to h...

discussion feature-request
 
Semiclassical
Semiclassical
5:03 PM
It's hard enough making a wikipeda of accurate science. Curating a wiki of all the ways one can do science wrong seems even harder.
 
Slereah
Slereah
that's Rational Wiki
and it's not doing a very good job
I should make a page on my site
THE LIES OF GR
 
bolbteppa
bolbteppa
It's mostly ridiculous, sometimes it's ok on completely opinionated anti-rational pages :p
 
Slereah
Slereah
About all the wrong things that are commonly told about GR
 
Nat
Nat
Hey folks, SE.QuantumComputing is currently in private beta, having started yesterday. "Private beta" seems like a misnomer, though, since folks can join if they like!
8
 
Anonymous
@Nat Uh, no. People who hadn't committed can't join at the moment. They'd have to wait for about a month
 
Slereah
Slereah
5:14 PM
I just joined and I didn't commit at all!
 
Anonymous
@Slereah Really?
 
Anonymous
Strange
 
Constantine Black
Constantine Black
Hi to all. A quick question: Is it completely wrong on the side of results to have a model where the group of transformations on the fields is independent of the base manifold(such that the fields as sections of the bundle are transformed under the group g and g is independent of the base manifold).
That way we do not care about gauge symmetry; I mean, could we get correct results that way, like thinking prior to Yang-Mills ?
 
Anonymous
I tried creating another account in Incognito mode, but it's not working
 
Nat
Nat
@Blue I tried it from another computer that wasn't logged in before making that claim. =P
 
Anonymous
5:15 PM
Anyway, if you can join, that's very good news
 
Slereah
Slereah
@ConstantineBlack I think all reasonable fields are at the very least tensor sections
They may have internal symmetries on top
But they still need to transform with coordinates
 
Anonymous
@Nat I see. I starred your message so that others can see :)
 
Anonymous
The new site's going strong
 
Nat
Nat
Hah it's definitely a fun topic.
@Blue Random curiosity if you care to share, what sort of background/field are you from?
@Blue Erm, right, strike that; I remember now.
 
Constantine Black
Constantine Black
@Slereah I'm discussing this internal symmetries; if for example I compute a feynman diagram with a lagrangian that has a global symmetry and not a local one( so the structure group of the bundle is independent of the base), will I take a completely wrong result, or that could be a case of a very certain gauge?
 
Slereah
Slereah
5:19 PM
What do you mean by "independant of the base"
do you mean that there's no Lorentz group structure to the bundle?
Like you just have a random vector bundle instead of the tangent bundle?
 
Anonymous
@Nat I had shared it in the QC chat :)
 
Anonymous
What about you?
 
Constantine Black
Constantine Black
I have a vector bundle that describes the internal degrees of freedom and the fields are sections of this bundle;
Example: I have a field f over Minkowski spacetime and a structure group g with a representation r on the fibres which are vector spaces for the fields and I have that:
: f'(x) = g f(x) , g is independent of x.
Maybe something I write doesn't make sense?
 
Slereah
Slereah
I mean, if you just have a global symmetry
 
Constantine Black
Constantine Black
I don't think of the Lorentz transformations of the fields.
 
Slereah
Slereah
5:24 PM
There's no need to involve bundles
 
Constantine Black
Constantine Black
What do you mean?
 
Nat
Nat
@Blue In the US, completed grad school a bit ago. Did a bunch of Science/Engineering degrees, plus an MBA to kinda prepare for the business side of things. I'm basically a Singularitarianist, so I'm working to create computational systems to effect general intelligence.
 
Slereah
Slereah
Local symmetries are done with the structure group of the fiber bundle
But
as far as I know, this isn't true of global symmetries
 
Anonymous
@Nat Cool! What was your grad school topic of focus?
 
Anonymous
CS?
 
Sir Cumference
Sir Cumference
5:28 PM
@Nat No thanks, I don't want to create a black hole when I use my computer
Wait in seriousness, beta sites can now get designs?
 
Mithrandir24601
Mithrandir24601
@SirCumference quantum computing is just that awesome
 
dmckee
dmckee
@Slereah My how things have changed.
In the current political climate the Confederate Jack in the background looks ... somehow off. Politically charged or tone deaf
 
Constantine Black
Constantine Black
Oh... then maybe I misunderstood something; I thought that a global symmetry was what I was writing above: the independence of the structure group from the base spacetime manifold. I got that impression from Baez's book, on the chapter of gauge symmetry where he argues that what Yang-Mills did waw to demand much more symmetry from the fields, so that g -->g(x) and still have invariant equations.
Thanks anyway. I'll take a look again.
 
Nat
Nat
@Blue Most of my personal research is in CS-like topics, but I basically tried to do everything in grad school.
@SirCumference And a sponsorship! If you join, Meta's got a question about how the new SE's got a corporate sponsor. They want to get more sponsors for SE in general (they seem to be having money problems), but they're testing it there.
 
Sir Cumference
Sir Cumference
Ugh, SE's selling out
 
Nat
Nat
5:34 PM
 
Slereah
Slereah
@ConstantineBlack I'd have to check
Hm
Are sections of the line bundle over the moebius strip globally invariant under reflection
 
Sir Cumference
Sir Cumference
Honestly, call me a pessimist but QC serves pretty tight niche that seems to slightly overlap with CS and TCS.
 
ACuriousMind
ACuriousMind
@SirCumference I've said from the beginning that most QC questions could be asked either here or on CS/TCS, but apparently that's not stopped people from thinking yet another SE site is a good idea :P
 
Nat
Nat
I'm kinda skeptical of the whole StackExchange model to begin with. I mean, I've got like 100 SE accounts now for different topics, and the number of SE's just keeps growing. It'd almost be nicer if they reformed the concept of scope limitations to be more like the tagging system.
 
ACuriousMind
ACuriousMind
@Qmechanic I'm doubtful of this benefit - how many users scroll down the entire front page now, don't click through to the second page, but would scroll down double the amount of questions?
 
Nat
Nat
5:43 PM
Besides the advantage for users - by which I mean, it's annoying to have only a bit of rep on each site - there're topics that don't cleanly fit into one SE vs. another. The solution seems to be to dissolve those arbitrary boundaries and instead have more of a mesh-like network, loosely separated by tagging. But, I guess that that'd invite complexity issues for many users.
I guess that that might conflict a bit with their new business model, though. And given their fiscal concerns, I suppose that they'll prefer to focus on getting some stability before experimenting with a change in network topology.
 
Anonymous
@Nat I don't seem to like huge sites with everything mixed up for some reason
 
Sir Cumference
Sir Cumference
Looking at the questions in the Definition state makes me wonder why so many people upvote >10 questions
 
Anonymous
But that said, I do feel there are too many software sites which could be merged with SO
 
Sir Cumference
Sir Cumference
 
ACuriousMind
ACuriousMind
@Blue SO is not about software, but about programming. The other sites (like SuperUser) were created specifically because their content was not really welcomed on SO.
 
Sir Cumference
Sir Cumference
5:49 PM
Honestly, SE could've just had a single site for programming, and a single site for comp sci
 
Tanuj
Tanuj
@JohnRennie are you around ?
 
Anonymous
@ACuriousMind Well, but still I do see lot of software (not programming) questions on SO everyday
 
Nat
Nat
@Blue Yeah, they'd need to make an appropriate interface for interacting with the combined network that could allow users the experiences they like, e.g. users who like the current views would ideally be able to basically retain 'em.
 
Sir Cumference
Sir Cumference
@ACuriousMind At the very least, SuperUser is a bit unique in that it's mostly focused on shortcuts and things to take advantage of
But programming, code review, etc. could all be made sections of SO
 
Anonymous
Yeah, especially code review
 
Sir Cumference
Sir Cumference
5:51 PM
We also don't need two math sites or two computer science sites, but there's no use in arguing it
 
ACuriousMind
ACuriousMind
@SirCumference The TCS/CS split has a similar history to the MO/math.SE split. Emilio has a wonderful meta post here with an overview of the history and reasons.
 
bolbteppa
bolbteppa
Who would have thought you would find a statement of the Kodaira embedding theorem in a physics video lecture
 
ACuriousMind
ACuriousMind
@SirCumference You need to think about sites more in terms of userbases, and especially the people who answer. The kind of person who enjoys answering short, well-defined programming questions is not necessarily the same kind of person willing to invest a lot of time open-endedly criticizing someone else's code, and is again different from the kind of person who enjoys arguing about software engineering practices in the abstract
Specific people may fall into all three categories, but the Venn diagram is very much not a single circle :P
 
Sir Cumference
Sir Cumference
@ACuriousMind Perhaps. But then again, SO is a massive and diverse userbase in its own right, far larger than the entire SE network combined. I can't say certainly, but I could imagine it working
If even a small percentage of its userbase were interested in reviewing code or arguing about software engineering practices, that may be sufficient
 
ACuriousMind
ACuriousMind
@SirCumference That small percentage is persumably already a large part of the users on these sites. I don't see what benefit would come from throwing everything back into a single pot.
 
Anonymous
6:01 PM
@SirCumference BTW the thing about the QC site is that probably it will attract people from mathematics, physics, electrical engineering as well as computer science. It's quite interdisciplinary and a growing field, so I personally feel that it needs a site of its own owing to the interdisciplinary nature. It's better than scattering the topic over a range of different sites.
 
Sir Cumference
Sir Cumference
@Blue I still don't see how it avoids overlapping with CS/TCS
 
Anonymous
@SirCumference Sure, it does overlap.
 
Anonymous
But as ACM said for the programming/software sites, the Venn diagram is surely not a single circle
 
Sir Cumference
Sir Cumference
I suppose. I'm just speaking from experience that many sites have been short lived for this reason.
Language learning, astronomy (sorta), etc.
 
Anonymous
Well, those aren't "growing" fields as such
 
Sir Cumference
Sir Cumference
6:07 PM
Quite the insult to LIGO :P
 
Anonymous
Nor are they interdisciplinary
 
Sid
Sid
Ooh, @Blue has gone away from The Dark Side™
 
Anonymous
Engineers don't do astronomy
 
Anonymous
Nor mathematicians as such
 
Anonymous
@Sid Heh, yeah
 
Anonymous
6:08 PM
How's it?
 
Sir Cumference
Sir Cumference
@Blue Well the ones who do go here :P
 
Anonymous
That's a good site!
 
Anonymous
Although looks a little low on traffic
 
Sir Cumference
Sir Cumference
It's also a matter of how many questions new users can think of. Compare with physics, where new users are commonly coming up with question about everyday life. I'm not too sure how many can be done with quantum computing.
Perhaps I am being too pessimistic, but that's just my worries
 
Anonymous
I'm indeed expecting the QC site's question rate to slow down gradually, but SE is supporting it and it's being sponsored so it's not gonna be a disastrous failure for sure
 
Sir Cumference
Sir Cumference
6:16 PM
0
A: How would you calculate the age of a non-flat universe?

DG123Hubble s constant, which is a measure of the rate of expansion of the universe, is in units of speed per unit length. It can be thought of as the speed of increase in the circumference of the universe divided by the length of the circumference of the universe. H = 2 pi c /2 pi R or after reducing...

Low quality?
 
vzn
vzn
@Nat hi, welcome, hope Quantum Computing makes it... hadnt heard about SE "new business model"/ "fiscal concerns" can you elaborate on that?
 
Anonymous
20
Q: Why does the Quantum Computing site look different?

Robert CartainoI recently announced a pilot program we are trying on Quantum Computing Stack Exchange, but rather than pointing you elsewhere, I decided to re-post the original announcement here. Enjoy! Sponsorship Pilot — Bringing resources BACK to Stack Exchange As our devs continue to work on features li...

discussion site-design
 
vzn
vzn
@Blue fyi hate to break it to you/ burst anyones bubble but actually there is a history of failed SE openings but SE doesnt archive them, hence quite a bit of mod skepticism. the new groups also basically compete with prior ones wrt subscribers. "sink or swim..." some "failed" SE site questions have been migrated to existing sites, saw that happen awhile back with Computer Science.
 
Anonymous
@vzn I am quite aware of that. But I guess I'm a big believer of trying out new things. Doesn't matter if the site fails. Life goes on as usual
 
Sir Cumference
Sir Cumference
"The hardest mathematics is counting because there is no shortcut for it"
What this textbook says
 
Slereah
Slereah
6:31 PM
what's the shortcut for category theory
 
Sir Cumference
Sir Cumference
I'm paraphrasing a bit but doesn't addition count?
 
vzn
vzn
@Blue yes do wish myself it was easier to launch new groups and attract particular audiences, but over years realized thats somewhat the tail wagging the dog... notice how few chat rooms on SE have much activity, even major topics like Computer Science are rather low traffic/ quiet. (have long wished theyd promote the chat rooms more.) but anyway just the launch of Quantum Computing is significant because very few new groups make it out of Area 51... (aptly named!) o_O
 
Anonymous
@SirCumference What book?
 
ACuriousMind
ACuriousMind
Very few groups make it out of Area 51 because most of the proposals are ill-defined or crackpottery :P
 
Sir Cumference
Sir Cumference
@Blue Some astronomy one,"Phase: a state of matter that is 'uniform throughout, not only in chemical composition but also in physical state.'
 
Anonymous
6:38 PM
Strange book
 
Sir Cumference
Sir Cumference
Sigh I thought I pasted the book name
hold on
@Slereah Seems to be working when I disconnect from my uni's internet
Weird
 
Slereah
Slereah
Maybe they have a filter
 
Emilio Pisanty
Emilio Pisanty
@Nat how come a private beta is themed?
 
Slereah
Slereah
Perhaps they filter my website due to the graphic nudity
 
Sir Cumference
Sir Cumference
20
Q: Why does the Quantum Computing site look different?

Robert CartainoI recently announced a pilot program we are trying on Quantum Computing Stack Exchange, but rather than pointing you elsewhere, I decided to re-post the original announcement here. Enjoy! Sponsorship Pilot — Bringing resources BACK to Stack Exchange As our devs continue to work on features li...

discussion site-design
Something to do with sponsoring
 
Emilio Pisanty
Emilio Pisanty
6:46 PM
@SirCumference yeah, figures
 
ACuriousMind
ACuriousMind
I find it very annoying not to be able to read that post without joining the beta :P
 
Anonymous
@ACuriousMind Business tactics :P
 
Anonymous
(Knowingly or unknowingly)
 
ACuriousMind
ACuriousMind
I have no interest in joining - I have no expertise in quantum computing and currently no questions.
 
Anonymous
That's fair enough
 
Sir Cumference
Sir Cumference
6:48 PM
@ACuriousMind You don't need to know anything or contribute to join a site :P
 
Slereah
Slereah
Now
Build a GR computer
 
Sir Cumference
Sir Cumference
It's free and they throw in 100 internet points
 
Slereah
Slereah
and we're talking
 
Anonymous
@ACuriousMind I could copy it the text to a google doc for you if you wish to read it without joining
 
Nat
Nat
 
ACuriousMind
ACuriousMind
6:49 PM
@SirCumference Sure, but the site doesn't derive any benefit from it either, and I'd forever have that useless account in my network accounts list.
 
Anonymous
I recently announced a pilot program we are trying on Quantum Computing Stack Exchange, but rather than pointing you elsewhere, I decided to re-post the original announcement here. Enjoy!

Sponsorship Pilot — Bringing resources BACK to Stack Exchange
As our devs continue to work on features like Talent and Channels (now called Teams), I've been anxiously looking for ways to increase engagement in our current Stack Exchange sites to help assure that development RETURNS to our Q&As… as soon as possible.
 
Anonymous
Here ^
 
Sir Cumference
Sir Cumference
@Slereah That'll build a black hole and we'll all die
 
ACuriousMind
ACuriousMind
@Blue Eh, I can wait until it's out of private beta :P
 
Slereah
Slereah
Not every GR solution is a black hole
 
diobuc eulb
diobuc eulb
6:50 PM
build a blackhole?
 
Sir Cumference
Sir Cumference
@ACuriousMind Until you delete it, but I guess so
 
diobuc eulb
diobuc eulb
what are the raw materials a black hole is made of
then
 
Sir Cumference
Sir Cumference
@diobuceulb Evil :P
 
Slereah
Slereah
mass
 
diobuc eulb
diobuc eulb
i wonder how the blueprints would look like
 
Anonymous
6:51 PM
@ACuriousMind Nowadays you can immediately delete SE sites which you join, if you have no posts there
 
Anonymous
I had tried it last month
 
Sir Cumference
Sir Cumference
@diobuceulb I think we've been over this
 
Nat
Nat
@ACuriousMind Here's a re-post of it on the main SE Meta: "Sponsorship Pilot — Bringing resources BACK to Stack Exchange".
 
Sir Cumference
Sir Cumference
 
diobuc eulb
diobuc eulb
@Blue actually it was like that since like december 2014
i can confirm
 
Slereah
Slereah
6:52 PM
1) yes
2) no
3) it radiates the evil
 
Sir Cumference
Sir Cumference
That is still my favorite question on SE
 
diobuc eulb
diobuc eulb
i still want to read the human female one
 
Sir Cumference
Sir Cumference
@diobuceulb Ahah, I remember that
Then there's the butterfly one
 
diobuc eulb
diobuc eulb
please when one of y’all gets to 10k remember to do that
 
Anonymous
@SirCumference Awesome :D
 
diobuc eulb
diobuc eulb
6:53 PM
and post it here
 
Anonymous
I love the first one
 
Sir Cumference
Sir Cumference
@diobuceulb Always take a pic of bad questions, they're nice when you're having a bad day
 
Nat
Nat
@SirCumference Now that's just sad!
 
Anonymous
That one was a bit touchy
 
diobuc eulb
diobuc eulb
last sentence lol
nice
 
Sir Cumference
Sir Cumference
6:55 PM
@Nat Maybe, but the fact that it was posted on physics SE doesn't make much sense
 
diobuc eulb
diobuc eulb
too bad ACM isnt human anyways
 
Sir Cumference
Sir Cumference
And then he responds to the mods with
 
diobuc eulb
diobuc eulb
that kind of rhetoric wont work
 
Sir Cumference
Sir Cumference
Nov 27 '17 at 19:53, by Sir Cumference
@RoryAlsop are you guys really like this or acting? how can you guys be so rude. I wish you be near death and something like this happens with your rescuer, only then will you understand cruel human. — Ram Keswani 2 hours ago
 
Nat
Nat
@SirCumference Hah no doubts there. It can be pretty hard to tell the troll posts from the real ones in those cases.
 
Sir Cumference
Sir Cumference
6:57 PM
@Nat JR sums it up pretty well
Nov 27 '17 at 15:06, by John Rennie
@0celo7 Butterflies don't go into comas. It was a dead butterfly. Posting that question showed only that the OP and reality are less related than is normally considered desirable.
 
CooperCape
CooperCape
I remember the comments on that post...
They were wild.
 
Nat
Nat
In all seriousness, those sorts of posts get me. I'm pretty sure that some of them are real while others are troll posts, and I can get really into trying to tell which is which.
 
Sir Cumference
Sir Cumference
@Nat Ah come on, you just gotta laugh at them sometimes. Like these
 
Slereah
Slereah
@SirCumference I hear they are lunatics
 
Nat
Nat
The Flat Earth Society is fun, too. The site itself is mostly a comedic bit, as are many of its members. But I'm pretty sure that at least a few members are for-real.
 
CooperCape
CooperCape
7:00 PM
@SirCumference Why'd you downvote though...
 
Nat
Nat
Trying to tell which-is-which there's a big challenge.
 
CooperCape
CooperCape
we want to encourage this
 
Nat
Nat
@SirCumference There needs to be a Meta discussion for these. =P
 
CooperCape
CooperCape
@Nat Could break the 'be nice' policy...
 
Sir Cumference
Sir Cumference
 
Sid
Sid
7:02 PM
@Nat But but... The Earth is flat.
 
Sir Cumference
Sir Cumference
I think I'll stop posting these, but still, they're needed once in a while
 
Nat
Nat
 
Semiclassical
Semiclassical
ow
 
Nat
Nat
@Sid Well, yeah, but no one outside of the New World Order's actually supposed to know that!
 
Semiclassical
Semiclassical
tbh flat earth conspiracy just seems kinda boring to me
 
Nat
Nat
7:06 PM
I mean, that's what we blow all of that money on chemtrails and water fluoridation for - to keep the population gullible and ignorant to the Earth's flatness! Otherwise, people might try to put hydroelectric dams up around the edges, putting Big Oil out of business. And if we stop "drilling for oil", then we won't have a convenient excuse to plant fake dinosaur bones to trick people into believing in evolution.
 
Emilio Pisanty
Emilio Pisanty
@heather Here, have an answer.
 
Slereah
Slereah
important theory
 
Sir Cumference
Sir Cumference
Quick question: is there a significant amount of neutral hydrogen in the Sun's atmosphere?
Compared to an O-type star, that is
 
Anonymous
@EmilioPisanty Welcome to the site :P
 
Nat
Nat
@SirCumference "Neutral", as-in, non-ionized?
 
CooperCape
CooperCape
7:10 PM
Strange works website is wacky af
 
Sir Cumference
Sir Cumference
@Nat Yep
 
Anonymous
I'm dying to see more technical posts like yours on the site
 
Anonymous
In case you're interested do have a look at my question:
 
Anonymous
6
Q: What exactly is meant by "noise" in the following context?

BlueThe strengthened version of the Church-Turing thesis states that: Any algorithmic process can be simulated efficiently using a Turing machine. Now, on page 5 (chapter 1), the book Quantum Computation and Quantum Information: 10th Anniversary Edition By Michael A. Nielsen, Isaac L. Chuang goes o...

quantum-computer noise
 
Anonymous
I'm not finding the answers there satisfactory
 
Emilio Pisanty
Emilio Pisanty
7:12 PM
@Blue @SirCumference @Nat oh, ffs
 
Sir Cumference
Sir Cumference
@dmckee IIRC you're pretty good with stars, right?
 
Emilio Pisanty
Emilio Pisanty
 
Sir Cumference
Sir Cumference
@EmilioPisanty Bahaha
 
CooperCape
CooperCape
@EmilioPisanty What is that 'q' though...
 
Nat
Nat
@Blue Huh, I thought the "noise" thing was pretty straightforward. What else did ya want to know about it?
 
dmckee
dmckee
7:14 PM
@SirCumference Like big, gas-ball, fusion reactors? I had one course in them twenty years ago. Does that qualify for "good with"?
 
Anonymous
The first answer uses a vague analogy while the second says it's just environmental noise
 
Sir Cumference
Sir Cumference
@dmckee Welp, my only question is: does the Sun have a significant amount of non-ionized hydrogen in its atmosphere, such that this can affect its spectral lines?
 
Nat
Nat
@Blue Yup, I wrote the first answer. =P I mean it's cool if you wanted something else, just trying to figure out what that'd be.
 
Anonymous
I had discussed this earlier with Mithrandir. The noise involved is a more inherent factor of the system.
 
Anonymous
I'm linking it, wait
 
Anonymous
7:17 PM
Jan 9 at 8:34, by Mithrandir24601
@Blue So, this is another 'general noise type' :) (presumably as a result of uncertainty intrinsic to the system). As a quantum Turing machine uses states (and is entirely equivalent to a classical Turing machine), it's not quite so clear cut as to whether this is taken into account or not. It probably depends how you model the problem or something.
 
Sir Cumference
Sir Cumference
Wait, nvm, it does have a lot of nonionized hydrogen in the chromosphere
 
ACuriousMind
ACuriousMind
@EmilioPisanty "A quantum of solace" would like to disagree
 
Sir Cumference
Sir Cumference
Which do interfere with the spectral lines
 
Anonymous
Jan 9 at 8:34, by Mithrandir24601
Also remember that you can repeat simulations as many times as you like, so you can recreate the exact state using an ideal quantum simulation, but maybe that's what you're saying. More also: To properly look into this would be very interesting, but would require a fair bit of time delving into it (has anyone properly proven this claim, or is this just another thing that everyone takes for granted?)
 
Anonymous
I'm pretty sure that it has something to do with noise in the context of information theory
 
CooperCape
CooperCape
7:19 PM
My phone's touch ID doesn't work with my fingers even straight after redoing it but as soon as I set a fingerprint with my nose it works.
At least I can open my phone like a fool.
 
Emilio Pisanty
Emilio Pisanty
@ACuriousMind so, you have no problem with, say, this?
user image
2
 
Nat
Nat
@Blue Kinda.. I mean, Information Theory underpins all of this. It's the same concept.
 
ACuriousMind
ACuriousMind
@EmilioPisanty No, I just wanted to pedantically point out that there are situations where quantum is, in fact, a noun :P
 
Anonymous
@Nat In short I was expecting a more technical answer with references to some relevant papers if possible
 
Anonymous
I'll wait for a few more days I suppose
 
Nat
Nat
7:24 PM
@Blue The concept of noise is a pretty basic one; it's basically whatever obstructs the contextual null state. I suspect that you might be trying to take it as something more specific than what's intended?
I mean, you're right that it's a general, information-theoretic thing. Stuff like thermal noise or quantum uncertainty are just subsets of it.
 
Anonymous
@Nat Yes, I want some answer to discuss all that explicitly
 
Anonymous
And how all those relate to each other
 
Nat
Nat
@Blue Kinda like list out a bunch of examples of noise and explain why they're called "noise"?
 
Anonymous
Information theoretic noise and thermal noise and the inherent quantum noise
 
Nat
Nat
@Blue I'd advise against separating them like that. They're not mutually exclusive concepts.
 
Anonymous
7:27 PM
@Nat I'm not separating them. I want to know how they relate to each other
 
Anonymous
There's not a single place on the internet which discusses this clearly
 
Nat
Nat
Yeah, I guess it's normally assumed to be intuitive because it's meant to be a simple, vague concept.
Noise is basically anything that is a deviation from the ideal signal.
Liike, that was a typo. The typo was a form of noise in this message.
Or static on an analog television's noise (in the television signal).
 
Anonymous
@Nat Does that type of distortion in a message during communication necessarily have any thermal effects?
 
Nat
Nat
@Blue Not in a context-independent sense, no. Not to say that there's an absence of noise, but rather that the concept of "thermal noise" wouldn't be generally meaningful in that question.
 
Anonymous
In one lecture Vazirani mentioned that if the distortion is irreversible then there's necessarily a $k_{B}T$ energy change...blah blah (shown by Von Neumann)
 
Anonymous
7:34 PM
After all that mumbo jumbo it becomes all the more confusing to digest
 
Nat
Nat
@Blue Sounds like a reference to Landauer's principle.
I'd regard a lot of that stuff as speculative. The logic behind it's not as solid as some would like to believe.
If it doesn't make perfect and complete sense to you, that's probably a good thing. =P
 
Anonymous
Heh
 
Anonymous
Well, reading it anyway
 
Anonymous
:P
 
Nat
Nat
Huh I did read a neat one a while back... lemme see if I can find it...
 
dmckee
dmckee
7:38 PM
@SirCumference Uhm ... ::looks in the text for the gen-ed astronomy class:: It seems the hydrogen lines are "relatively faint" for G-class stars.
 
Sir Cumference
Sir Cumference
Thanks, but I already got things sorted out :)
Sigh, this stuff is so tedious
 
Nat
Nat
Yeah, here's the original paper: "Irreversibility and Heat Generation in the Computing Process" (1961).
 
Tanuj
Tanuj
@Blue quick question
 
Anonymous
@Nat Aha. That's the one I guess I was looking for
 
Tanuj
Tanuj
how do I differentiate this wrt x so as to to get the derivative independent of $a$ : $\sqrt{1-x^2} + \sqrt{1-y^2}=a(x-y)$ .
 
Anonymous
7:41 PM
Differentiate the equation as it is and then substitute $a$
 
Sir Cumference
Sir Cumference
@Tanuj Let $a = 0$
 
Tanuj
Tanuj
@SirCumference actually , I don't have to get it independent of a but I have to express the derivative entirely in terms of x and y
So putting a =0 doesn't make sense
 
Sir Cumference
Sir Cumference
@Tanuj Blue's got the right answer
 
Tanuj
Tanuj
@Blue I'm getting it wrong , I get $dy/dx=1$ , which is not the answer.
 
Anonymous
Write down your steps
 
Sir Cumference
Sir Cumference
7:49 PM
Is $x$ and $y$ independent
 
Tanuj
Tanuj
@Blue damn ! I got it , missed one part completely.
Thanks :)
 
Anonymous
Cool!
 
Tanuj
Tanuj
@Blue advice .
@Blue Should I give test at my institutes everyday (Tests are not discussed there) Or should I go for three tests per week at my home and study with that ?
 
Balarka Sen
Balarka Sen
@SirCumference I have this one saved as a screenshot
 
Anonymous
@Tanuj Giving tests at home isn't very fruitful normally because you get distracted. Better give them there and try to solve the remaining parts once you're back home
 
Nat
Nat
7:53 PM
@Blue Here's a 2017 book with content on the topic: books.google.com/books?id=fR8vDwAAQBAJ&pg=PA90
 
Sir Cumference
Sir Cumference
user image
4
 
Tanuj
Tanuj
@Blue okay
 
Anonymous
@Nat Thanks! I'll go through it tomorrow. Too sleepy now :)
 
Balarka Sen
Balarka Sen
@SirCumference Beautiful
 
Anonymous
@SirCumference The Darth Vader one is absolutely hilarious
 
Balarka Sen
Balarka Sen
7:56 PM
You're not big on Star Wars are you?
I could tell, given that misspelling
 
Anonymous
I'm sleepy
 
Nat
Nat
@SirCumference xD
@Blue Sleep is good. You dream, and dreams are awesome. Sometimes you can even fly!
@SirCumference The funniest are probably the seen-by-PI/Professor. Poor grad students. xD
 
Sir Cumference
Sir Cumference
@Nat I don't think I've dreamt in a year. I must be doing it wrong
Well, sometimes I dream about math, but that's only if I study too much
 
Nat
Nat
@SirCumference Ack, not remembering dreams can bite! But dreaming of math can be cool; I've actually been reasonably successful doing some practical work in dreams before. Usually happens after spending a long afternoon working on a hard problem, then kinda dream of it as a continuation of the thought process.
 
Sir Cumference
Sir Cumference
Last night I dreamt I was a Lebesgue integral. The week before I woke up telling myself I had to shower, and wondering what kind of function a shower is.
 
Nat
Nat
8:10 PM
Wait, do images work in here? !xkcd.
Peanuts.
 
Slereah
Slereah
 
Nat
Nat
@Slereah ?!!?!?! HOW ?!?!?!??
 
Slereah
Slereah
wizard
powers
 
Nat
Nat
Oh. Silly me. xD
 
diobuc eulb
diobuc eulb
@SirCumference it’s a parabola i think
with some air resistance business in there maybe actually
 
Balarka Sen
Balarka Sen
8:16 PM
It's the exact same mechanism as throwing a ball and finding it's trajectory
Which is a parabola
Well, modulo all the air resistance bullshite
 
diobuc eulb
diobuc eulb
nerd
 
Balarka Sen
Balarka Sen
no u
 
diobuc eulb
diobuc eulb
i know you are but what am i
good luck coming back from that
you’ll need it
 
Balarka Sen
Balarka Sen
the response is going to be via discord
done
 
diobuc eulb
diobuc eulb
ban Salarka Ben @mods
 
Sir Cumference
Sir Cumference
8:23 PM
@diobuceulb Nah I think I was wondering whether it was a scalar or vector function
 
 
1 hour later…
diobuc eulb
diobuc eulb
9:36 PM
vector i guess because fluid flows can be described by vector fields
but if you’re just thinking about the shape then parabola
 
dmckee
dmckee
Anyone have a estimate of the dynamic viscosity of electrophoresis gel?
 
Jake Rose
Jake Rose
$\int_{x=x_0}^{} \textbf{F} \cdot \textbf{n} dS$
What does this notation with no upper limit mean guys?
 
dmckee
dmckee
I could use it to add some interest to a problem for my physics for bio-maors class.
@JakeRose It means that you are going to have the upper limit left in the expression you get at the end. A sloppy but not-uncommon usage.
 
Jake Rose
Jake Rose
What do you mean?
Let me write out where this came from
 
diobuc eulb
diobuc eulb
@ACuriousMind I found one of your squad members
 
Jake Rose
Jake Rose
9:47 PM
$\int_{z_1}^{z_2}\int_{y_1}^{y_2} \int_{x_1}^{x_2} F_x(x_2,y,z)-F_x(x_1,y,z) dydz $
And then the limits represent a cuboid
Alligned with the axis
 
dmckee
dmckee
10:00 PM
I found some viscosity numbers on my own. But they vary over 4 orders of magnitude. Grrrr...
I've punted by picking on that makes the question come out the way I want it.
It's good to be the Professor.
But not as good as being the King.
Aside from summers off, of course. That's better.
 
diobuc eulb
diobuc eulb
10:28 PM
@ACuriousMind
SAP
care to explain how you’re going to talk your way out of this one???
if you’re not trying to take over the world then why did you send your friends here?
 
ACuriousMind
ACuriousMind
10:48 PM
@diobuceulb I never claimed SAP doesn't want to take over the world :P
 
Balarka Sen
Balarka Sen
ASAP Bjorn
 
diobuc eulb
diobuc eulb
lmao
 
Balarka Sen
Balarka Sen
@ACuriousMind when's the string theory mixtape coming up?
 
ACuriousMind
ACuriousMind
Hm? Trust me, you don't want to hear me making music :P
 
nbro
nbro
Yo, check this joke out!
How do you call a person who reads while handstanding?
 
Balarka Sen
Balarka Sen
10:53 PM
@ACuriousMind I could ghostwrite for you
 
nbro
nbro
lol
 
ACuriousMind
ACuriousMind
@BalarkaSen Send me a draft and I'll consider it
 
nbro
nbro
The problem is when a chat has the following motto "don't ask to ask", and then forgets to warn its visitors, and the visitors ask "may I ask if may ask before asking"
 
ACuriousMind
ACuriousMind
@nbro It's right in the room description.
 
nbro
nbro
@ACuriousMind Yes, I know, I am joking :)
Just thinking about possibly funny situations
Btw, a new SE site about quantum computing is now in private beta! If anyone here is interested to join it ;)
 
ACuriousMind
ACuriousMind
11:05 PM
@nbro If you direct your view towards the starboard, you'll see you're late to the party ;)
 
diobuc eulb
diobuc eulb
@ACuriousMind rap this
yo yo yo this is asap bjo
string theory was a farce
so now i do a 9-5 while i parse
 
Balarka Sen
Balarka Sen
diobuc you'll get hired by the asap mob if you keep spitting fire like this
 
diobuc eulb
diobuc eulb
i guess when it's my turn to realize string theory is getting me nowhere i can always become a rapper
it's nice to have a plan b later in life
 
Secret
Secret
11:49 PM
in Mathematics, 4 hours ago, by Balarka Sen
I can call a mod from hbar if this continues
we have been plague by this random overstarring problem for years and I think the community wants to know who is behind this
 
Kelthar
Kelthar
@DanielSank it's okay, thanks!
 
Secret
Secret
@Loong @ACuriousMind @DavidZ if you don't mind, can you guys use your mod powers to find out who is overstarring the math chat cause all the local mods there are not active for a long time
 
00:00 - 17:0017:00 - 00:00

« first day (2686 days earlier)      last day (2226 days later) »