[a / b / c / d / e / f / g / gif / h / hr / k / m / o / p / r / s / t / u / v / vg / vr / w / wg] [i / ic] [r9k] [s4s] [vip] [cm / hm / lgbt / y] [3 / aco / adv / an / asp / biz / cgl / ck / co / diy / fa / fit / gd / hc / his / int / jp / lit / mlp / mu / n / news / out / po / pol / qst / sci / soc / sp / tg / toy / trv / tv / vp / wsg / wsr / x] [Settings] [Home]
Board
/sci/ - Science & Math

 Name Options Subject Comment Verification 4chan Pass users can bypass this verification. [Learn More] [Login] File Please read the Rules and FAQ before posting.Use TeX with $tags for inline and [eqn] tags for block equations.Right-click equations to view the source.  10/04/16 New board for 4chan Pass users: /vip/ - Very Important Posts 06/20/16 New 4chan Banner Contest with a chance to win a 4chan Pass! See the contest page for details. 05/08/16 Janitor acceptance emails will be sent out over the coming weeks. Make sure to check your spam box! [Hide] [Show All] By popular demand you can now support 4chan directly: Give to support 4chan Cooldown time lowered for 4chan Pass users! You can now renew your Pass if it expires in less than 6 months. Don't forget the banner contest [Catalog] [Archive] File: sciguide.jpg (9 KB, 200x140) 9 KB JPG https://sites.google.com/site/scienceandmathguide/ >> Reminder: /sci/ is for discussing topics pertaining to science and mathematics, not for helping you with your homework or helping you figure out your career path. If you want advice regarding college/university or your career path, go to /adv/ - Advice. If you want help with your homework, go to /wsr/ - Worksafe Requests. What careers are there for a BS in Math? A BS in Stats? >> File: 1457530667043.jpg (201 KB, 804x1204) 201 KB JPG I heard that Burger King is hiring. You can try McDonald's too, but I'm afraid they ask for a master's degree. >> >>8425789 academia software developer NSA finance food service/other >> >>8425789 Do some very, very basic reseach yourself. Short answer: pretty much anything. What are the best universities in EU for studying maths at undergrad? > must be affordable (I.e. not england) > course must be in English or German 26 replies and 5 images omitted. Click here to view. >> >>8423229 >EU kek >> >>8423229 What the fuck is the EU? It's just an economical organization REEEEEEEEEE. Best universities in the european continent besides U.K fuck don't know. Although in Portugal there are very good and affordable Universities well classified in the world rankings, like coimbra, oporto and minho. >> >>8423229 read the sticky and die in a fire >> >>8423229 Nobel prize winning uni here >> >>8423425 ETH is a university http://www.topuniversities.com/university-rankings/world-university-rankings/2015 I'm curious, are there any neurological diseases that cause dependence on other people, and how would said disease be treated? >> >>8426647 Unrequited love. Unfortunately there is no cure. It will eventually lead to death by suicide. >> >>8426647 All diseases that make you handicapped will make you dependent on other people. For example MS, ALS, dementia, stroke, etc etc. >> >>8426972 This. Still alive because of porn and math >> >>8426647 Isn't Dependent Personality Disorder literally what you are looking for? >> >>8426647 Opiate addiction. Because they don't stop asking other people for money. I think we all know what the treatment is. File: STEM1.png (155 KB, 1692x720) 155 KB PNG Currently in my second year of college. I aiming for a Bachelors degree in CompSci. Did i just fall for a meme, or it is what one should do? What about Quantum, how different is it from CompSci? 29 replies and 5 images omitted. Click here to view. >> >>8422636 You wont be begging for a job anon. >>8423309 >CS jobs You mean programmer jobs. There is a difference. I have no degree and I have a programmer job. Everyone can land one of those jobs. Making apps, front-end, backend, gameplay programmer, ect... You don't even need to be good at math, just some basic analytical thinking skills. But those aren't the jobs CS degrees are for. CS degrees are for jobs more demanding in other scientific fields. Often you need to work together with other engineers or need to have good math skills. >> >>8426736 >Software plateaued years ago You're retarded. We're not just talking about making apps for the play store. Automation requires software. Who is gonna program all these self driving cars, robots, satellites, ect... CS is also research. Research into AI, computer vision, better compression algorithms, ect... >> >>8426897 >There are huge breakthroughs to be made in artificial intelligence >>>/g/tfo kid >> >>8426897 > 1. Computer Science is not same as "software". Most CS grads don't do research. Most computer "scientists" are software engineers. Most software engineers are more architects and construction workers: building scaffolding and data conduits, writing skins around databases, importing libraries they didn't write, using someone else's mathematical abstractions because they only vaguely remember matrix multiplication. Calculus? What the fuck is that? They shuffle through billions of KLOC to extend existing logic and pray they don't unravel some untenable ball of yarn left by the last guy. In particular, most of Silicon Valley works on shit that won't last and doesn't matter. Practicing meaningless interview questions just to get hired. Tremendous wastes of potential. > 2. There are huge breakthroughs to be made in artificial intelligence. Careful, you're in danger of revealing your embarassment. If you even have a menial grasp of the surface tension of this concept, you would know that machine learning is nothing more than a bag of tricks. How does the computer identify a cat? Oh, some clever math on a 2D matrix. Does it know what a cat is? No. It has no capacity for understanding, intuition, or generalization. There's clearly headroom, but don't fall into the popsci trope. It's ML not AI. > 3. There are a lot of computational problems that are still very inefficient to solve. This is purely mathematical (which CS is a subset) and strictly academic. Like I said, very few CS grads go into pure research. Those aren't problems that businesses solve. Further to point, private industry could give a shit about efficiency at all. The average webpage size is 2MB which is atrocious for mostly text. The web is becoming almost unusable with extraneous kludge. >> >>8426941 > You're retarded Thanks for the complement. > We're not just talking about making apps for the play store. Yet what are 95% of CS grads working on? Shit. Useless shit. Squandering their intellectual potential chasing VC skirts in an attempt to cash out on "who-gives-a-shit-about-the-idea-is-it-worth-money?" > Automation requires software. Yes, it does. Not disputing that. > self driving cars, robots, satellites, ect Self driving anything is going to require effectively a machine which is sentient to cover all of those dark corner cases (rain, snow, gravel roads, etc). The term "robots" has been bastardized by popsci to mean virtually anything technologically magic, so I don't have a hard target to respond to. And satellites, code, yep, but it probably isn't revolutionary. Much of it structures across well established libraries. > Research into AI, computer vision, better compression algorithms Computer science research is a subset of mathematics, and as I stated, compared to the volume of those versed in CS, very few actually do it. Does your OS actually anticipate your responses? Does understand the data it processes? Wake me up when you're not just clicking boxes to open more boxes. File: download (1).jpg (4 KB, 194x259) 4 KB JPG Are there any actual people here attending ivy leagues? Or are the majority of people on here college drop outs with an interest in science? I wanna know who I am associating with here. 83 replies and 12 images omitted. Click here to view. >> Michigan here Study Computer Science/Math >> >>8423080 >Are there any actual people here attending ivy leagues? Or are the majority of people on here college drop outs with an interest in science? I have a master's degree in math from a tier 1 public university. Whatever that's worth. Also, whoever's thinking about going to USC, don't go to USC >> >>8423080 I mow lawns. The slope averages 21' in these hills and i hate it >> >>8426412 aren't you embarrassed to post this? >> >>8423361 Overqualified for a lab technician job, bruh. That's probably why you didn't get it, sorry to say. File: 1475668034393.jpg (395 KB, 1154x1500) 395 KB JPG So /sci/ you think you're smart huh? Especially the smug fucking physicists. Let me ask you something, if all observables are meant to correspond to hermitian operators then why is the kinetic energy operator of the Hamiltonian in cylindrical coordinates for the not a hermitian operator? Let me elaborate, there is a term in the operator involving the first order derivative with respect to the radial coordinate and this ruins the symmetry of the operator. File: groupsnstuff.jpg (94 KB, 512x512) 94 KB JPG Feel free to post about mathematics in general, just keep the shitposting about 300k starting, CS, and stuff out of this thread. Let's actually talk about something meaningful this time. >what are you currently reading? >any problems? >any suggestions for cool exercises? Personally right now I am doing some reading in Kähler manifolds, in particular from the viewpoint of symplectic geometry. I was wondering if anyone has any good books on differential equations as that has been a very abandoned subject for me since my undergraduate years. Maybe there is a good book in Springer's library? Thanks! 255 replies and 49 images omitted. Click here to view. >> >>8426757 please learn to use google https://en.wikipedia.org/wiki/Root-finding_algorithm >> >>8426760 Thanks anon! I wanted to know if there is a much better to way find roots. >> >>8416312 Do you have reason for this to make sense, or is this just "look at it. Just look at it" kind of making sense. Regardless look up the extended real/complex numbers. >> Well, I'm currently taking Topology and it's awesome. I'm also learning about matrix groups and linear operators and shit with linear algebra for my thesis. It's been particularly interesting using quaternions. I'm also learning about mathematical methods in physics which is pretty cool and regression analysis which is more interesting than expected. >> How do you do, guys? Tell me something amazing you've realized recently Help me /sci/, I know you can. My current speaker setup displays an extremely strange phenomenon. I keep my speakers running at all times and between them is roughly a 15ft wire connecting the unpowered speaker to the power source-speaker combo. In addition, there is a 15ft 3.5mm male-male wire connecting my laptop to the aux input. Sometimes (very rarely), the speakers output a foreign signal that sounds similar to an AM or CB radio broadcast. I don't understand why this is happening. Please help, this is seriously confusing me. File: paqDI7XE.jpg (203 KB, 1252x1252) 203 KB JPG What would you attempt to do if you knew you could not fail? 58 replies and 9 images omitted. Click here to view. >> >>8424012 I would ride my bike with no handlebars. >> 1. Right all of my wrongs. 2. Teach as many as I could the importance of intellectual honesty. 3. Try to influence the political arena in areas of meta-analysis, paperwork reduction, (pro-social) futurist agendas, etc. 4. Start a movement to help those on the fringes of society. 5. Explore as much as I could about what it means to be a myself, a human, a living creature and something "existing". 6. Spend time trying to learn as much as I could, for both intellectual reasons and practical applications. >> Stop masturbating. >> >>8424012 Race war. clean all the degenerates in the world >> >>8424012 Summon my waifu so we could finally live together, forever. File: black.jpg (3 KB, 251x201) 3 KB JPG This shit really scare me. What is the possibility that one comes close to our solar system? Should I fear this happen? do not know why, but lately it has given me afraid. pic related, black hole. 8 replies and 1 image omitted. Click here to view. >> File: 1447384639353.png (643 KB, 633x758) 643 KB PNG >>8426506 That would be amazing if Planet X was actually a small black hole, assuming it had a stable orbit that wouldn't wreak havoc on the planets or the Sun. Just imagine the research potential if we could study one of them up close instead of having to study them from thousands of light years away. We could have a live recording of matter being absorbed by a black hole in real time instead of artistic interpretations and grainy pixels from telescopes. >> File: giant BH.jpg (88 KB, 960x960) 88 KB JPG >>8426126 >> >>8426759 Fuck... too big... >> >>8426126 It looks like the belly button of cosmos. >> >>8426506 >While it's no threat, it does mean those fuckers might be either more common than we would like them to be or we got the short end of the stick. How is that "the short end of the stick"? a 10 Earth-mass black hole that's within reach of current spacecraft would be amazing. File: 7vmsxs9caosx.jpg (380 KB, 2295x5411) 380 KB JPG They can't even get a rocket into orbit without it exploding, so why do people think that they'll be able to build THIS in 5 years? Serious question. 53 replies and 8 images omitted. Click here to view. >> >>8426256 >Is the "fucktardedly huge rocket" concept even viable past a certain scale? Yes. It is the "financial data" (advertised prices etc) that are from fantasy land. >> >>8426679 What the fuck dude. I agree colonizing Mars is a waste of time. But the amount of resources it would take to get there, really, is not all that much compared to the scale of the problems you mention. And developing cheap, easy transit to low earth orbit is very valuable. As far as energy is concerned, that is really not an issue, OPEC can't push prices on their cheap easily available oil too high or the US starts fracking and brings it back down, we are already moving in the direction of sustainable energy, the idea of some energy industry collapse causing mass chaos and starvation is some utter insanity that hasn't even been relevant for a decade. >> >>8425909 >Serious bait fgt pls >> >>8426325 >>8426320 Seconded, fuel is cheap. Of course the Raptor engine (and new ITS system) will be fueled by cryogenic methane and oxygen instead of kerosene and oxygen, don't know how the cost will compare...but it was designed that way because methane can be produced on Mars to refuel the engines for the return trip. >> >>8427044 You can make synthetic kerosene on mars too Methane was picked for a whole buncha reasons, not solely because of ISRU on mars. File: _20161020_041257.jpg (33 KB, 605x310) 33 KB JPG OK /sci/, which one will get us to Mars faster? 32 replies and 3 images omitted. Click here to view. >> >>8424568 Why not both make huge space ships that are particle accelerators. also Hillary is the one advocating most for the New World Order which is pretty much the only way to start considering making space travel more viable, or at least improving its infrastructure. Russia is against the NWO however becuase they are the place where most rockets get launched now. >> After arguing with NASA engineers for over a week now because these geniuses can't admit they botched some basic geometry, fuck'em, they need de-funding. Source: me, I work in the cryogenics industry. >> >>8425235 This >> >>8424480 Trump wants to make peace with Putin retard. Also thank you for Correcting the Record. >> >>8424480 I've actually met someone who thought trump was tied to Putin but also thought that trump would start a war with russia. I asked him how he could hold these two views simultaneously and he couldn't answer me either. File: PAY-Ancient-object.jpg (44 KB, 615x384) 44 KB JPG I suspect carbon dating is not accurate. Case in point; this 250,000 year old artifact. Is it an airplane part? its an aluminum alloy. 21 replies and 5 images omitted. Click here to view. >> >>8425746 Carbon dating is totally inaccurate. We have dinosaur flesh that atheists claim is mega old. Yet it is dinosaur flesh that has still not decomposed. >> >>8426823 Carbon dating only became a thing after people decided the Earth was millions of years old. >> >>8425785 Wait, where's the giant dragon? I want to see! >> >>8426804 Nice Sokal. >> >>8425746 What the fuck are you talking about. Carbon dating only works on things that once lived and less than 50k years old. Nowhere in that article they say anything about carbon dating >>8425767 File: the book cover.jpg (265 KB, 1352x1528) 265 KB JPG https://youtu.be/Fd2d7Uq_8wY https://docs.ufpr.br/~danielsantos/ProbabilisticRobotics.pdf Let's try to initiate a book reading. This time, as suggested in that "one are you doing right now" thread, by moderating it with short rants of summary, elaborations and asking questions. As explained in the video, the book seems approachable for a whole bunch of majors, which is why I think it makes a good candidate, and should this work out as I intent, people can go on tangents in various directions. Sorry for the possibly quite bad accent. An edition of the book pops up if you type in the title in google. It's not the latest edition, but the chapters seem to match. The second one chapter starts with some probability theory basics (gonna post a screenshot of the .pdf posted above in the next post). I'll continue reading and if there's interest, I will make a short rant about it maybe even tomorrow. I'll post questions, by me and for other, or add hints at interesting stuff, if I think that's necessary. If there's eventually even a video response, some discussion of any of the topics that come up, that would be even more interesting. 24 replies and 10 images omitted. Click here to view. >> >>8427004 Thanks for the bump. I've just written down a programming task and will also summarize it in a video, mabye later. This is on https://en.wikipedia.org/wiki/Hidden_Markov_model --------------------------------- Okay, so today let's care about the example in the text again. It's from p.24 here: https://docs.ufpr.br/~danielsantos/ProbabilisticRobotics.pdf I've posted the 5 relevant pages here: http://imgur.com/a/WHaay Here, let's discuss what we need for a computer implementation where we abstract all the particular chances (numbers in [0,1]) in the pdf: - You have a door that's in one of two states [math] x : Bool$:
x = "open"

>>
You need one initial assumption
$bel_n0_open : [0,1]$
and set
$bel(0, open) := bel0open$

At each time step, he first can take an action (u) and afterwards measured the door and updates his believe.

You need a model for sensor data z (same type as state in this case)
and
action effects u (a bool, try or dont try to open the door):
Those probabilities are time independent in our model, i.e. given by a few numbers:

1. the chance $Z_{x\,closed} : [0,1]$ that his sensor gives the right answer when the door is closed
2. the chance $Z_{x\,open} : [0,1]$ that his sensor gives the right answer when the door is open

3. the chance $U_{x\,closed} : [0,1]$ that he managed to open the door after he tried open a closed door

Written as functions, we have the conditionals

$p_{zx} : Bool \to (Bool \to [0,1])$

>>
File: arnold arm.jpg (52 KB, 1000x623)
52 KB JPG
Program specification:

------

The code should thus do the following:

When we start we must enter the game parameters (in the command line, say)
>Chance a closed door is measured to be closed" (sets Z_x_closed)
>Chance an open door is measured to be closed" (sets Z_x_open)
>Chance a closed door is opened when he tries to do so (sets U_x_closed)
>Initial believed that the door is open" (sets bel_n0_open)
A random number generator sets the state x to open or closed without telling us.
The game starts, n=0.
The chance bel_n0_open that the door is open is displayed.
>I am 100*bel_n0_open % sure that the door is open.
We're asked if we want to take an action:
>Do you want to try to open the door or quit? y/n/q
We enter "y" OR "n". (i.e. u="try" OR u="dont")
If we try to open the door, the hidden state x is updated, with the chance given by $p_{x,ux}$ (use a random number generator with those chances).
With the new state, according to $p_{zx}$, we measure the system (random number generator again) and the measurement result is displayed:

>>
The second question should be
>Chance an open door is measured to be open