[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 / qa] [cm / hm / lgbt / y] [3 / aco / adv / an / asp / bant / 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] [Search] [Home]
Settings Home
/sci/ - Science & Math

4chan Pass users can bypass this verification. [Learn More] [Login]
  • Please read the Rules and FAQ before posting.
  • Use with [math] tags for inline and [eqn] tags for block equations.
  • Right-click equations to view the source.

05/04/17New trial board added: /bant/ - International/Random
10/04/16New board for 4chan Pass users: /vip/ - Very Important Posts
06/20/16New 4chan Banner Contest with a chance to win a 4chan Pass! See the contest page for details.
[Hide] [Show All]

Please consider donating to help the victims of the KyoAni studio fire: https://www.gofundme.com/f/help-kyoani-heal

[Catalog] [Archive]

File: tri.png (52 KB, 528x494)
52 KB
Would you consider size a spacial dimension? You can move inward and outward, bidirectionally. You can measure how far in and out you can go. Why not consider it a dimension?
6 replies omitted. Click here to view.
So fucking boring. Who cares what you call it? Debating over definitions isn't interesting
File: 1465461979605.jpg (75 KB, 641x491)
75 KB
It's a gain in chaos. So entropy dissolving is evident.
Or do you legitimately think that name calling is a academic method and citation means absolute?
good picture
schizos detected
abandon thread
File: 1466238930563.jpg (264 KB, 828x1340)
264 KB
264 KB JPG

Its related to a black body radiation problem where I want to get the spectral radiance in a defined spectral region (I simplified the notation but x is the wavelength, N is just a product of constants). You can ignore the integration limits for now. Can you get some reasonable terms through integration by parts?

>t. not a physics nor mathfag and
I do this out of curiosity.
9 replies and 1 image omitted. Click here to view.
If you continue doing this and does not use u=1/x then the exponential integral [math]Ei(x)[/math] shows up. Why? Using u=1/x from the start has a solution expresed only in rational functions and its tormenting my mind.
embarrassing post desu
File: planck_integ.gif (4 KB, 617x149)
4 KB
Here is the original form of the equation. I was trying to figure out how I can get the radiant energy emitted from a black body at temperature T in a given wavelength interval. In practical terms the wavelength interval is determined by the use of a shortpass filter that has a bandwidth of about 50 nm at full width at half-maximum so somehow I'd need to fit in a Gaussian curve over the integrated value so it gets sort of complicated. Still interesting to think about it though.
ever heard of wollfram alpha nigger?
also always LMAOing at all the guys at math.stack who think that just because they find a closed form for an integral means they are doing real maths
>ever heard of wollfram alpha nigger?
I have, here is another one I just found and it seems cool https://www.integral-calculator.com/

File: psued.jpg (67 KB, 1280x720)
67 KB
Books on how time could be or is nonlinear?
Do you want to write some?

Literally you can just teleport 60 times per second and be still all the other time.

No book.
Still Alice was popular once
Do you want science fiction or write a book?
File: 1561295086796.jpg (591 KB, 2048x1365)
591 KB
591 KB JPG
List of experimental evidence:

Aether doesn't exist.
Speed of light is constant.
Time dilatation in more independent observers.
Light has duality.

Please, because you sound like you're just kidding or you really think that there is a horse somewhere hidden in the train,

I think you just don't accept that ...

Where can I get diploma from physics where I can get hands on really rare material?
It was more of a demand than list...

But if you post them here, I can elaborate.

File: Binary Sunset.jpg (67 KB, 1024x605)
67 KB
Physics PhD student here, I was wondering if anyone here has felt unhappy with their grad school experience?

I initially pursued this degree out of a simple love of physics and some general idealistic sense of helping humanity. However, as time went by, these feelings faded, worn away by an ever growing list of things that bothered me:

>Environment is hostile/cuthroat
There isn't just rivalries between different groups at varying universities, which is its own disappoint, but people in different subfields in our own university treat each other like shit. I've seen AMO profs argue against CM labs getting more funding, for no defined reason.

>Work overtakes life
I know people who work 12 hours a day minimum, and come in on Saturday. Its not even a matter of profs imposing it on their students, it's so ingrained in the culture that if you don't work like this then others will assume you're lazy and mock you.

>No/few relationships to make
People don't even want to talk to you unless you can help advance their career or help them in making a paper. That's not even to mention how it's deeply implied that you shouldn't try to get married or start a family (as it'd be a "waste of time")

>No love of research
This one hurts me the most. People don't seem to give a shit about the physics or anything besides getting published. It all seems like a career game.
301 replies and 18 images omitted. Click here to view.
Most people have 2 or more fields Anon...
There are no jobs for Chemical Engineers and no sign that this will improve within the next 10 years.

If I could have any degree instead of a ChemE PhD it would be a computer science masters in data science/ML.
I stayed at my inbred home town university so that I could be with my girlfriend while she finished her degree.

Do you have advice for me? I'm about to finish my PhD at the same university I did my Masters and Bachelors, but I really, really want to start a new one at a better university, or just any university in another country. I'm 26 so I'm getting a bit too old, but I'm hoping that some PIs are still willing to take me based on my publication record.
>There are no jobs for Chemical Engineers and no sign that this will improve within the next 10 years.
There is always a need for well qualified patent attorneys and patent Examiners.
This is nonsense. My friend finished a law degree while working for a petroleum company and he still hasn't found work at a patent firm.

Chemical engineering got oversaturated and it's not going to recover because people are still under the false impression that it has a healthy job market.

File: 87786452087.jpg (94 KB, 700x450)
94 KB
Is eugenics viable? Could you use selective breeding processes to raise populations intelligence?
109 replies and 6 images omitted. Click here to view.
>Is eugenics viable?
A better question would be
>Does it stop being eugenics if we don't know what we're doing?
It's always eugenics all the time. There is always an environment and it is always selecting for something, even if we don't care to find out what it is. Any social environment we maintain is selecting for something, and if we enforce that social environment with the intent of selecting for that something, it would be "eugenics", but if we enforce that social environment for other reasons, and simply chose to remain ignorant about what it selects for, it would suddenly no longer be "eugenics", despite being objectively identical.
Not if you continue to clamp and vaccinate.
frequently not "powerfully"
They're basically the ultimate social parasites
what's interesting is that their cognitive abilities are somewhat localised their visual spatial abilities are actually below average for europeans which means they're under represented in art or design, their linguistic and reasoning abilities are where they excel hence their prominent presence in finance, law and physics/maths.
>look up the khazarian mafia or the Kosher Nostra
How does this relate to the discussion here?

File: 1416330533273457807.gif (2.97 MB, 250x250)
2.97 MB
2.97 MB GIF
what is your motivation to do science? what is your motivation to wake up in a morning?
File: 1473150951973.jpg (91 KB, 600x800)
91 KB
Well consuming media isn't yielding dividends..
Even Google stopped serving me ads because I'm that much of a sink.
Soo.. I guess because I can't pull the trigger?
Doesn't really balance out with the mystery to unravel.
To live at my deathbed at 106 years old and smugly say "See? I knew life was shit all the way through. I was right all along.". I don't do more science than I need to in order to get a job.

File: IMG_20190722_031422.jpg (1.62 MB, 3475x2817)
1.62 MB
1.62 MB JPG
So I've whipped up this design for a constant current/voltage power supply. The pic is a simplified version but contains most relevant details. I already have it up and running on a proto board and it seems to work rather well up to 30-40W.

The only way I could stabilize it was by trying different compensation caps/'impedances', and given all of the different active devices I wasn't able to apply my somewhat limited control theory knowledge to stabilize it. However, the constant current, while stable, will produce some odd waveforms when the load is pulsed.

So my main question is how can I model a BJT for "control block diagram" purposes? I have the pole-zero eqns mapped out for the op-amps, but can't figure out how to model a BJT as a large-signal freq dependent block.
Alternatively, anyone have advice for how this type of circuit should be analyzed/designed if it were say commercially produced? From what I've seen/heard, actual engineers wouldn't be using this type of approach but I don't see how they could use intuition to know that this type of circuit would be stable..
>Whipped up this design for a constant voltage supply.

Nigga that's called a transistor.
Sounds like someone skipped his introduction to analog electronics course.
bitch you didn't even quote my post so that joke doesn't work

no, well technically yes, but I passed the course. Regardless, from what I can interpret, I can't use small signal models because they depend on gm/r_pi which is in turn dependent on the DC bias current which is irrelevant in comparison to a 1A transient, for example.

Further, the only beta(jw) eqn I can find depends on gm as well. I suppose i could just use the classic beta equation, but I noticed that certain BJTs drastically alter the loop parameters.
pls rec some books on electronics

File: ga.jpg (77 KB, 1600x900)
77 KB
Do they walk among us?
27 replies and 6 images omitted. Click here to view.

Why should we be alone? The fact that there have been countless radar-confirmed sightings of abnormal-physics aircraft is surely evidence against us being alone.

We've checked how many planets for life? We can be sure there's no other indigenous intelligent life in this system, but what about the other hundred billion systems?

I don't understand people who think we're alone. If we had scouted more than a billionth of the stars in this galacy, it would be a more convincing argument.
>Why should we be alone?
I didn't say we should. I said I think we are. If there was another planet in our universe containing life, there are a few probable likelihoods.
>primitive bacteria-like life forms
>said life is unrecognizable to us as life at all
>organisms are advanced beyond us to a degree that contact will never occur
I don't treat this shit like a religion, so the existence of extraterrestrial life doesn't exactly excite me as much as it used to when I was younger. Though I'm not a scientist, nor am I a STEM major at some university. I'm just a machinist who admires what man is capable of. In my case, the Apollo program specifically.
File: 1509394159885.jpg (794 KB, 1754x1252)
794 KB
794 KB JPG

One does.
>absence of evidence is not evidence of absence
absence of evidence of absence is not evidence either

File: 1563748213226.jpg (71 KB, 670x812)
71 KB
Common lisp is actually a superset of mathematics.
This is true.
mathematics was invented slightly before computers came about

File: hqdefault.jpg (37 KB, 480x360)
37 KB
when do you think if and when automation will kill all jobs ?

and what will happen then ?

will there still be rich and poor people?
will we all be equal ?

will we use gene editing to become immortal demigods with high iq that will conquer the universe ?
45 replies and 7 images omitted. Click here to view.
>UBI office with 40% of the rest if America to collect my post scarcity check

How many people actually work now.
Not students, prisoners, retirees, children, mentally and physically handicapped, drug users, the idol rich.

How many people actually get up and go to a job every day?
>When will automation kill jobs?
Never, there are too many jobs and there always will be, that's why we need mass migration.
Well, I think if a lot of people are without a job they will do something for it. By democracy if that doesn't help, revolution or even war is a last option. But people are not going the take the rising poverty sitting down. If the automation doesn't help the people themselves, they're going to do about it by democracy at first.

You would have a massive all-encompassing infrastructure to subjucate the masses like you said. I don't think it's going to be a thing if people care for their democracy, privacy, inequality, even hippie-sounding stuff like human rights, now and in the future. I think that just the mere amount of people is enough to stop that kind of development like you said. Of course, people must actually do something to stop that kind of development. People must be active. But I think they will get active if things gets worse and worse.
He's not making any leaps of logic. Natural selection doesn't just disappear because intelligence exists, it's just a mechanism whereby systems more adapted to self propagation outpropagate others. This can be applied to anything from genes to organisms to societies. It doesn't have to be a single program or device, the system of society itself can be viewed as an "actor" in the field of natural selection. A self propagating system (like an economy) progressively discarding human elements in competition with others is definitely something that can and likely will happen. We already see this happening, even if now the nodes making the decisions are still human.
I don't understand why so many people struggle to understand the difference between technological innovation that creates a net increase in jobs (1919) and the kind that creates a net decrease in jobs (2019).
>nnnnuuuuugggghhh all technological progress is exactly the same and will always be exactly the same, don't be a Luddite!!
3 million truckers aren't going to learn to program, nor would they be needed if they did. Advances in AI mean that fewer programmers are needed, not more. 3 million burger flippers aren't needed to maintain technologies that are learning to self-maintain.

Daily reminder that the moon landing was faked and you are all suckers for believing it.

Try and prove that it even happened to begin with. Pro tip: you can’t.
192 replies and 31 images omitted. Click here to view.
what the fuck are you on about
Just ignore him. He's just a troll trying to be (in)famous.
Wow, you made me shiver. I was reminded of the inflammable cancer years ago.
tripfags should kyoani themselves

What major scientific breakthroughs can we realistically expect to see in the 2020's?
264 replies and 50 images omitted. Click here to view.
Not neccesarily, anti-scientific sentiment does not always imply religiosity (take Ted K for example). More due to some of its negative effects, politicizations and misuse. Though I don't think this will be the dominant societal trend, I just think it will be a very major one, discussed openly and having political ramifications.
Replace psychology with philosophy, and then this is correct
Philosophy isn't a real thing though.
[spoiler]hopefully baldness[/spoiler]
I think we will see less and less breakthroughs as time goes on. 2020 isnt a magical year where advancement is allowed to happen. So don't expect much.

File: chessboard.jpg (127 KB, 1179x887)
127 KB
127 KB JPG
Since chess is only middleweight brainlet tier pattern recognition, which is the most G-factor/IQ responsive game?
241 replies and 23 images omitted. Click here to view.
>people hate people who are smarter than them
no. people just don't like people that are condescending, just don't be an asshole, gain some social skills and you should dominate any social landscape.
katamari is definiteley up there you need a high level of spatial awareness to be good at it.
I was reading a letter in the daily telegraph this morning that mentioned Alan Turing used to play a variant of chess where after every move you took you would have to run a distance
your total for every run was then used as a component of the final score. Which adds a physical component to a chess game.
I was wondering if you could possibly combine 960 chess with some sort of physical activity like an obstacle course or run?
You mean like chess boxing?
preferably something else that isn't going to cause long term brain damage

File: images.jpg (26 KB, 590x350)
26 KB
What kind of practical applications of quantum physics (mainly entanglement) can we hope to see in the future?
It's useful for quantum computing, so if you believe google and those other big companies you will see it used in the first quantum supremacy computers in the next couple years, where they'll be performing the actually fairly useless task of some random matrix calculation. Anything beyond that is a bit unknown since it's not clear quantum computers will ever be sufficiently powerful for the real applications.

There's also some interest in the presence of entanglement in things like photosynthesis which might be relevant for people doing artificial photosynthesis.
Whoa that sounds wacky. Didnt realise photosynthesis had quantum effects in it
Cold fusion maybe if somebody get's it done.
There are already tons that have been in use for decades. ""Entangled photons"" have been in use in coherent light fiber optics for a long time.

File: 1562828344010.png (446 KB, 415x454)
446 KB
446 KB PNG
Hello /sci/

I earned a BS in biochemistry and molecular biology with a minor in math, 4.0 GPA. I would like to know whether or not I should apply for a PhD program in biomedical engineering given that info and nothing else. Advisors and specific research are something that I'm looking into. Despite all of the advice I've received from my mentors I'm still here looking for somebody to tear me down if I'm being too arrogant. All of my research thus far has been within molecular biology with the exception of some light computational biostatistics work.
16 replies and 4 images omitted. Click here to view.
what if he’s not a pedophile?
Go to /adv/. This is a board for scientists.
You're right, I've been wasting everybody's time. I think I've heard all I need to at this point. I shouldn't go any further because I'm competing with people who didn't pick a shit undergrad degree. Fuck I'm miserable.
This is /sci/ anno 2019, most people here will never see the inside of a university. That being said, BME anon is probably right, but if you care about improving your prospects have you considered bioinformatics? Coding is a universally transferable skill.
>Fuck I'm miserable.
Don't be, you have a STEM job, that's more than most STEM grads have. Just stick with and build your career as best as possible.

Delete Post: [File Only] Style:
[1] [2] [3] [4] [5] [6] [7] [8] [9] [10]
[1] [2] [3] [4] [5] [6] [7] [8] [9] [10]
[Disable Mobile View / Use Desktop Site]

[Enable Mobile View / Use Mobile Site]

All trademarks and copyrights on this page are owned by their respective parties. Images uploaded are the responsibility of the Poster. Comments are owned by the Poster.