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/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.  05/04/17 New trial board added: /bant/ - International/Random 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. [Hide] [Show All] [Catalog] [Archive] Global warming is not rea- https://www.euronews.com/2019/06/17/the-viral-image-that-illustrates-the-scale-of-melting-ice-in-greenland >Danish climatologist Steffen M. Olsen captured the image above on June 13 on a routine mission through the Inglefield Gulf in northwest Greenland. >Olsen had the difficult task of retrieving measuring devices that had been planted on the ice for the Blue Action mission. But when he set out with his dog sled, he found that the ice sheet was hidden beneath a shallow lake of water. >Figures from the National Snow & Ice Data Center show that approximately 712,000 km2 of Greenland’s surface has melted on June 12th, more than 470,000 km2 more than the same date in 2018. This was also more than 600,000km2 more than the median average from 1981 to 2010. Over 40% of Greenland experienced melting on that one day alone, with total ice loss estimated to be more than 2 gigatons (equal to 2 billion tons). >In 2012, Greenland experienced the most melting on record, when, for a few days, 97% of the entire ice sheet indicated surface melting. Those monitoring the ice sheet say 2019 could rival this figure. 6 replies and 1 image omitted. Click here to view. >> >>10735461 it's ice water >> >oh the ice is covered with 0C water >the dogs legs wont by insulated once their fur is wet >fuck it lets just have them pull us anyway are Danes fucking cunts? >> >> >>10736134 damb >> >>10735436 It looks like a good place to live. wtf i love climate change now I don't get reactive power. Let's say we have an R L circuit where 99% of the impedance comes from L and the remaining 1% comes from R. We apply Ohm's law and with let's say 10 V we get, for example, I = 4 A. So then we have 39.6 VAr and 0.4 W and if I have understood this shit correctly there are 4 amps circulating at 10 V but the resistor is just dissipating 0.4 W?? Why? Do electrons not hit the conductor's ions now or what? Where is the Joule effect? >> >>10735336 Magnetic fields and shit, ask Tesla. >> >>10735336 you got it wrong. if it’s a DC circuit, which your example implies, then L can be replaced with a straight wire and you get 40W. AC circuits are more sophisticated and you need to have time-varying currents, and the resistor and inductor share who is radiating away the power >> File: 1560177446835.jpg (27 KB, 554x554) 27 KB JPG >>10735373 Wrong inductors only become "shorts" when time goes to infinity. Besides when the system is turned on you get exponential characteristics for current through the inductor In fantasy art we tend to see a lot of warriors and/or monster girls/demihumans, like Minotaur girls, with large breasts, sometimes inhumanly so (not even counting the examples like giants, or even who are significantly larger than humans yet have a similar, albeit scaled up, physiology). I recently started thinking about how such biology would work. Given that larger breasts would have more mass, and thus more weight, what adaptations would be needed for these individuals to avoid the lower back pain, sagging, and other issues that this could cause? 16 replies and 2 images omitted. Click here to view. >> >>10732516 Anyone know? >> >>10730450 Hey Metro Man! >> >>10732516 >>10733684 communication >> >>10735026 Is that an actual person and not an edit? >> File: 241185_p0.jpg (52 KB, 384x480) 52 KB JPG >>10725036 The breasts drawn by crabman are usually within mostergirls. SAID monstergirls are ONLY monstergirls since THE TITS are UNAFFECTED by GRAVITY! You science niggers are dumb. What programs are best at simulating planets, especially taking into account things like plate tectonics and/or weather patterns? >> a giant array in a python program >> >>10734977 A what program? >> >>10734971 Anyone? >> >>10734971 I guess you want a global circulation model, but those usually don't have plate tectonics. Check out SimEarth. File: bacteriophage.png (635 KB, 686x960) 635 KB PNG Please explain to me how the fuck bacteriophages came to be. Every fucking other microscopic lifeform is blob like or irregular in some way and then you fucking get this geometrical construction of some fucking dodecahedron standing on arthropod looking legs with fucking spikes and an injection system for DNA. How in the FUCK did this thing come to be. If it was evolution, how the fuck does that work for something that can't even reproduce on its own? How does natural selection happen for viruses? There is nothing as eerie and alien looking as these things. 158 replies and 29 images omitted. Click here to view. >> >>10728176 God. >> >>10728202 On the internet, no one knows your a trilobite >> >>10733549 Counterargument: That kidney continues to metabolize (and in fact would die if left without access to metabolic substrates) even after being removed. If I pull one of the many viruses from that kidney donor and put it on the bench or in any acellular media, it will just sit there, doing nothing, until the end of time (or realistically until its capsid is deactivated). Since it performs zero (0) metabolic functions, it isn't any more alive than a piece of DNA left in a test tube, even if changes. >> >>10729354 Read some Pythagoras my guy >> >>10736145 Or make a jiggling 4d etch-a-sketch inside a 4d jiggling etch-a-sketch.. How is exposure to radiation treated? How does the body react to amounts beyond what is normally safe, and what is that limit? 12 replies and 2 images omitted. Click here to view. >> >>10733695 The aesthetic and culture was better back then. >> File: demon core .jpg (21 KB, 400x225) 21 KB JPG . >> >>10733698 Demon core? >> >>10735095 Núcleo del demonio! >> >>10735166 English! I heard somewhere that while obviously rare, it IS possible for a woman to become pregnant and then get pregnant AGAIN sometime later while still pregnant with the first embryo, is that correct? If yes, why does it happen? If not, what prevents it from happening? 5 replies and 1 image omitted. Click here to view. >> >>10729985 What causes that to happen? >> >>10732504 Biology isn't perfect and things go wrong. >> >>10732514 Any specific causes? >> >>10729985 What health risks does that cause? >> ba-bump Thread about how the set of real numbers is R = (-inf,inf) and the real number field is some other thing which is vastly more complicated than the set of all real numbers R. >> >>10736114 i cant read it theres a bunny in the way >> File: TIMESAND___QDRH.jpg (1.17 MB, 2816x2624) 1.17 MB JPG File: images (12).jpg (20 KB, 298x169) 20 KB JPG In the distant future, if we ever manage to start terraforming planets into environments better suited to us, what are some tricks that could be used to maximize the amount of space that humans could use to live, grow crops, etc, assuming that the inhabitants are limited to 21st-century technology, or stuff that we know for sure is possible but can't build yet, maybe due to it being a sort of space penal colony or something? 3 replies omitted. Click here to view. >> Just splice ant genes into human dna and we'll be crawling over each other in tunnels and shit working mindlessly for muh queen >> >>10732117 >china >> >>10732054 Not helpful. >> >>10732127 What? >> Bumpin' File: lm-landing-gear.jpg (491 KB, 1857x2286) 491 KB JPG LM Landing Gear edition. Apollo 11 landing gear extended at 098:15, reported back minutes later: https://history.nasa.gov/afj/ap11fj/16day5-landing-prep.html#0982707 Apollo 12 landing gear extended at 104:48. https://history.nasa.gov/afj/ap12fj/12day5_prep_landing.html Apollo 14 landing gear extended at ??? Apollo 15 landing gear extended on or about 098, verified shortly afterward during separation: https://history.nasa.gov/afj/ap12fj/12day5_prep_landing.html Apollo 16 landing gear extended at 93:59: https://history.nasa.gov/afj/ap16fj/13_Day5_Pt1.html Apollo 17 landing gear extended at ??? 18 replies and 5 images omitted. Click here to view. >> File: longlongman.png (305 KB, 500x599) 305 KB PNG >>10736011 LONG LONG MAAAAAaaAAaaAAN >> suppose we had a lunar rotovator to help mined rare metal payloads to escape the moon and inject to earth What would we use for the first stage of the flight to the bottom of the rotovator? >> >>10736123 a big hook >> >>10735850 Where in the Apollo 17 website can I find confirmation of LM landing gear extension/deployment? (I'll have to answer my own question again but still). >> >>10735734 Are those sphericals on the joints? How close are we to creating habitable arcologies? What would we need to make them? What features will most arcologies probably share? 78 replies and 21 images omitted. Click here to view. >> >>10733338 >*per-colonization *pre >> >>10732625 less dense population per area is also better for defense. >> >>10721136 Yes, please. I want my iCology >> >>10733469 Please, elaborate on that. Sources? >> >>10721021 Cool picture. File: maxresdefault.jpg (96 KB, 1280x720) 96 KB JPG What is your favorite planet in the solar system? 17 replies and 2 images omitted. Click here to view. >> >>10734427 Moon >> >>10734793 >Earth obviously, everywhere else is shittier Earth has biological life forms (literally shit) >>10734427 Jupiter obviously. You do realize how vital Jupiter is in terms of the formation of the solar system, right? >> I think I will go with Neptune. >> >>10735437 Agreed anon, saturn is the prettiest boi >> For me, it's Europa File: evolution-1011341.jpg (36 KB, 590x350) 36 KB JPG how do you see human evolution progressing? File: shitty-diagra.png (8 KB, 640x640) 8 KB PNG If I spin a plasma of ionized gas around in a circle Wouldn't it create a magnetic field like a solenoid? How big would the B field be in terms of angular velocity? I feel like the result would be the something like the product of charge density and angular velocity but am not good at vector calculus. >> >>10735976 probably. Doing this with plasma is hard. Why don't you use sodium potassium alloy instead? It should work just as well. Make sure to use a bunch. >> File: doxy.png (175 KB, 305x271) 175 KB PNG Okay, so we got a mass [math]m$ of gas spinning round in a circle with radius $R$. Gas has charge $Q=\rho m$ where $\rho$ is charge density and angular velocity $\omega$.

A current found wherever there is moving charge so $i=\frac{dQ}{dt}=\frac{\rho m\omega}{2\pi}$

Biot-Savart Law says [eqn]\mathbf{B}=-\frac{\mu_0}{4\pi}\int_C\frac{\mathbf{r}\times i\ d\mathbf{l}}{|\mathbf{r}|^3}[/eqn]

We have the two vectors in the cross product be perpendicular over the whole path $C$, and we can simply determine the direction of B from the right hand rule.
So in terms of magnitude [eqn]B=\frac{\mu_0}{4\pi}\cdot\frac{\rho m\omega R^2}{R^3}=\frac{\mu_0\rho m\omega}{4\pi R}[/eqn] .

So yeah, you were exactly right. The magnetic field is exactly proportional to the product of charge density, mass and angular velocity; and is inversely proportional to the radius of the circle.
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How do I stop being such a math brainlet? I'm gonna take Linear Algebra, Calc 2 and Discrete Math this fall. While I wouldn't say I'm aiming for an A I definitely want to do well in all of them, especially Calc 2 since I struggled the first time. Any advice?
>>
>>10735602
That's pretty much the plan. I'm working on my calc 2 textbook from limits onword. My goal is to spend 2 hours daily and do as many problems as possible. That way I figure even if I can't do all the chapters I'll have a solid foundation going into the class.
>>
>>10734799
thats the right attitude

>>10735173
kill yourself
>>
>>10735744
actually based and truthpilled
>>
>>10735933
>>10735744
Is your reading comprehension really this shit? He said you should gtfo if you're challenged by ENTRY LEVEL material. Studying cohomology is gonna be hard for most people, even people who are decent at math, because its highly abstract, so these are courses you'll probably need to put work into. Calc 2 is covered in high school where I live, and people who want to be musicians, plumbers or chefs do ok.
>>
>>10736081
wow its like we arent talking about graduate level topics here. also, lot of schools dont offer calc 2 in hs. calc can be hard if you get a shit prof

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