/sqt/ - simple questions thread (aka /qtddtot/)Previous thread: >>16893204>what is /sqt/ for?Basic questions regarding maths and science. Also homework.>where do I go for advice?>>>/sci/scg or >>>/adv/>where do I go for other questions and requests?>>>/wsr/ >>>/g/sqt >>>/diy/sqt etc.>how do I post math symbols (Latex)?rentry.org/sci-latex-v1>a plain google search didn't return anything, is there anything else I should try before asking the question here?scholar.google.com>where can I search for proofs?proofwiki.org>where can I look up if the question has already been asked here?warosu.org/scieientei.xyz/sci>how do I optimize an image losslessly?trimage.orgpnggauntlet.com>how do I find the source of an image?images.google.comtineye.comsaucenao.comiqdb.org>where can I get:>books?libgen.rsannas-archive.orgstitz-zeager.comopenstax.orgactivecalculus.org>articles?sci-hub.st>book recs?4chan-science.fandom.com/wiki//sci/_Wikimath.ucr.edu/home/baez/physics/Administrivia/booklist.html>online courses and lectures?khanacademy.org>charts?imgur.com/a/pHfMGwEimgur.com/a/ZZDVNk1>tables, properties and material selection?www.engineeringtoolbox.comwww.matweb.comwww.chemspider.comTips for asking questions here:>avoid replying to yourself>ask anonymously>recheck the Latex before posting>ignore shitpost replies>avoid getting into arguments>do not tell us where is it you came from>do not mention how [other place] didn't answer your question so you're reposting it here>if you need to ask for clarification fifteen times in a row, try to make the sequence easy to read through>I'm not reading your handwriting>I'm not flipping that sideways picture>I'm not google translating your spanish>don't ask to ask>don't ask for a hint if you want a solution>xyproblem.info
Any recent news involving quantum computing?
>>16945820Anyone?
Holy kek this /sqt/ is on life support
>>16946435Don't worry, it'll be up and going right after spring break.
Can someone do my homework, it's a geogebra question thing making a construction for the Riemann integrals, thanks y'all <3
>>16947913ask ai
>>16947913If you can construct the diagram like this, that could work out alright in Geogebra
>>16949655no...
>>16949655>muh aikys
has qc surpassed the 40 qubit number or whatever it was 5 years ago? I mean actual qubits that can be entangled and used, not some meme marketing number.
>>16953175ask ai
>>16953180ai is bought and paid for by qc companies and their not useful qubit counts
https://www.youtube.com/watch?v=JtSYeftGUGEDid he use LLM to rewrite his script? The style just gives me LLM vibe.
>>16947913>it's a geogebra questionhttps://www.geogebra.org/
>>16956910I don't think so because at 5:18 mark, he used ChatGPT to "cross-reference with the devil"
What is the most elegant "triangle inequality check"?
>>16957721s = (a + b + c)/2If (s – a)*(s – b)*(s – c) > 0, then the side lengths form a triangle.Otherwise they don't.
>>16957721Basically the same as >>16957863, but just check if (a+b-c)(a-b+c)(-a+b+c) > 0, cause triangle equality says all 3 terms are positive and it isn't possible for 2 to be negative. No need to consider area
>>16944314I want to make a borax mixture, as explained here: https://alsnetbiz.com/homeimprovement/homemade.html (the "equivalent to Bora-Care". instructions under "Prepare the concentrate")I plan on using propylene glycol, and heating the mix in an electric kettle made of glass and/or a ceramic pot.is this propylene glycol as safe as the instructions say? is the borates mix safe enough to reuse the pot, or should I only keep it for chemical stuff in the future?
>>16958715>propylene glycolthey put it in food and cosmedic products, and is a laxative
>>16958904yeah, that's why I chose to use it instead of the ethylene.still, I want to be as cautious as possible. that's why I'm asking.what about the borax and boric acid? also wonder about the gases. at 260°F I can imagine some nasty things might form and fly from the mix?
>>16958170>(a+b-c)(a-b+c)(-a+b+c)= (a + b – c)*(a + c – b)*(b + c – a) = (a + b + c – 2*c)*(a + b + c – 2*b)*(a + b + c – 2*a) = (2*s – 2*c)*(2*s – 2*b)*(2*s – 2*a) = 2*(s – c)*2*(s – b)*2*(s – a) = 2^3*(s – a)*(s – b)*(s – c)
>>16959149This post was invisible for more than one hour. That's why I accidentally posted it a second time. It only became visible after I posted it the second time.
>>16944314>13 days>25 postsJUST
>>16958918>wonder about the gasesNo harmful gases should come off, borates will not decompose from the heat and they wont react with anything in your mixture.Dont reuse the pot for making food borates are toxic to eat keep that pot for chemistry/junk
>Le particle is in a bunch of places at once until it's measured, then it's in one placeSo how do they know that it was in a bunch of places at once before they measured it? Nobody ever actually describes the experiment, they just show you the alleged conclusion and go "ooh, spooky science!"
>>16960315Because they perform experiments. That was what the 2022 Nobel Prize was for.It's also what the Dual Slit experiment demonstrates, which is why it is brought up all the time. It's the simplest experiment that shows the particle can't be in a single place before it is measured.
>>16960337The claim of self-interference is not reducible to an empirically verifiable sequence. The label of self-interference is hyper specified to particular experimental arrangements not having anything to do with self-interference of one or more underlying elements. Consider an experiment that sets out to demonstrate a claim about an element interacting with itself. There is no means to isolate the element from the experimental apparatus or any of its partial interactions without reflexively destroying the claim of self. As such, the inductive chain does not exist and the conclusion about underlying particles or emissions is confabulation. A further paradox arises when trying to minimally fit the frame to the apparatus and experimental parameters. We don't even get to say a self-cycle is occurring by the same logic before.
>>16960404> when AI halucinates
What are the best books from a beginner's perspective for embedded systems and aerospace engineering, particularly astronautics?
So, if you push a long thin rod into a wormhole with a throat diameter smaller than its length sideways, what happens? Does the rod bend around the curved spacetime of the wormhole until it hits itself?
What are the three acute angles equal to (in radians)?Hints:h = [irrelevant]S(r) = {(x, y): |x| < r, |y – h/2| < Sqrt[r^2 – x^2] + h/2}region 1 = S(7)facecolor = (G + C)/2region 2 = S(5)facecolor = G = greenregion 3 = S(3)facecolor = (G + Y)/2region 4 = [irrelevant]facecolor = Gregion 5 = {(x, y): |x| < 1, |y + 9/2| < h + 9/2}facecolor = Y = yellowregion 6 = [irrelevant]facecolor = C = cyan
I have to design and complete a research project/paper (for Geoscience) for my major. If I'm understanding, I'll have eight weeks for design and prep, and eight weeks to complete it, with some time in between the two courses.How do I...do a research project? I swear half the time I Just try to come up with something that sounds like I can get credit for it and toss it at the wall but that's probably not a good idea for a final level assignment.
>>16961592The kinda goofy, but overall answer to this is "follow the scientific method":1. Pick a phenomenon or a problem (maybe even one that seems obvious -- a good jumping off place is "extra credit problems you may have had on tests," because that's how profs often talk about their own real research.)2. Make a hypothesis about a solution to that problem -- what do you need to test to prove if it's true or if a technique is "good"? What assumptions does that require? 3. Hit the literature & find papers and books around the topic. Use the keywords from 2. to dig -- to start, you really should use actual library tools or your textbooks to find papers etc., but Google Scholar also works. (Your school probably has a research guide for a particular field like this: https://libraries.etsu.edu/research/guides/geosciences/methods)4. You'll probably end up getting an answer to some of your idea through the literature, but there's probably a gap or someone not doing a good job explaining why or having shitty code or whatever. Bingo, there's your Thing To Do. 5. Iterate There's also a textbook, "Research Methods in Geography" that you can probably find on libgen or by searching around.
>>16961027y = –Sqrt[r^2 – x^2]Tan[θ] = dy/dx = –x/yα = π/2 – θ = ArcSec[Abs[r]/x]If r > 0 and x = 1 (which is the case), then α = ArcSec[r].Thus the acute angles are ArcSec[3], ArcSec[5], and ArcSec[7] from top to bottom.
>>16961610Thank you. I found that book. It was free for whatever reason, praise be to abdul or whoever uploaded it.
Solve Fermi’s paradox from a biologist’s point of view.
>>16961027>G = green>Y = yellow>C = cyanThat one is based on the dark blue one, on the wall.
>>16962475Get out there and take tissue samples from the few planets we can land on, nerd.
Consider the trumpet formed by rotating the curve around e^{-ax}. A wire coils around it at some particular angle starting from x = 0. It makes an angle theta at the meridian of x = 0. What is its length at x = t?
>>16963753I meant rotating the curve of e^-ax around x axis.
>>16963753> A wire coils around it at some particular angle starting from x = 0.> It makes an angle theta at the meridian of x = 0.> What is its length at x = t?Huh?? I have no idea what you are even trying to describe.Maybe try a better picture?
>>16963753Before you post a problem, you should ask yourself, "Is the problem unique?" Is the problem constructed in a unique way (or more interestingly, is the solution constant over some space)? Do you really think boundary conditions are enough for this problem to hold a unique solution? Or do you think that the solution is path independent and requires no further info? If you're asking for homework, radial coordinates have orthogonal tangent vectors for the differential, so the length element is simply [math] \sqrt{ r^2 \dot\theta^2 + (1+ \tfrac{dz}{dr}^2)\ \dot{r}^2 } ds [/math], when parametrized by length s
there used to be this google drive full of math books, do you guys know if it's back up/been reuploaded?
>>16963916>Do you really think boundary conditions are enough for this problem to hold a unique solution?No, I forgot to mention the angle is supposed to be constant.
>>16964469The problem is easy. The differential tangent basis vector to the tangent space at a point for the angular coordinate phi is always tangent and parallel to the surface parallels, and the same for the radial tangent vector to the meridian, so constant angle to the meridian also is constant angle to the parallel, and parametrizing by arc length means the arc tangent vector on the surface will have constant coordinates [math] (dr/ds, d\phi/ds) = ( \tfrac{ \cos\theta) }{ \sqrt{ 1 + (dz/dr)^2 } } , \sin\theta/r ) [/math] for each tangent space. Since z(r) is a function, change the arc length line element from ds to dr (not d\phi), and plug in [math] \tfrac{ d\phi }{ dr } [/math], and plug the integral into wolfram alpha
>>16963916change the \dot\theta to \dot\phi, since you said theta was the constant
Little plant seeds should be sown at least 1 cm apart from each other to be sown properly. You have a circular pot whose diameter is one meter. You throw the seeds into the pot randomly. Despite throwing them in there like that, you want there to be at least 70% probability that all the seeds are sown properly (no two seeds are closer than 1 cm apart).What is the maximum number of seeds that you can sow?
>>16965305ask AI
Does the nature of constantly needing to find 'novel' research subjects essentially create a race to be as esoteric as possible as you try to write your five or six publications a year?
>>16965305It's just the circle packing problem but for 70% of the seeds, and for the other 30% you place them all in a single point
>>16965305If I wanted at least 70% probability of success, I'd not throw them randomly like a giant fag.
What is the maximum number of faces a solid can have whose faces are polygons that are all identical in shape and size?
>>16966476You question is slightly ambiguous so it's either one of:-- Regular polygon faces (Platonic solid) 20 (icosahedron)-- Any congruent polygon faces 120 (disdyakis triacontahedron)
>>16966596I see how that works. Icosahedron has 20 equilateral triangles as faces so when you split up each into six congruent triangles you get a solid that now has 120 faces. But how do you prove that is the maximum?
>>16967098It comes down to the fact that around each vertex the angle must be < 360°. This combined with the known angles of each regular polygons impose a constraint on the possible number of sides the polygon can have and the number of vertices. If you know about Euler's Formula [math]V − E + F = 2[/math], you can work it out from that too. Essentially it's a hard upper limit of 3D space.
Calculus depends on uncountable sets to produce interesting results; the Lebesgue integral of [math]f:[0,1]\to\{0,1\}; x\in\mathbb Q\mapsto0, x\notin\mathbb Q\mapsto1[/math] is [math]1[/math].So in some sense, "quantized" behaviour is analytically irrelevant. What does that imply then for physics and physical limits? As I understand it, there is some minimal unit, the Planck length, in which physics can happen. Then, how does a path integral work, when a particle can only occupy a finite amount of spaces between any two points?
>be home schooled>"you don't need to know that" for tons of subjects especially math>I need to know it for my job and virtually all my hobbies/interestsI went from 2nd grade level math to about 5th grade thanks to khan academy, youtube, and some book I got at the thrift store. I want to get to at-least highschool level math. Now that I am exploring concepts that are new to me, it'd be nice to have something I can just punch in the numbers and get correct answers, to see if I get the answer I am expecting to get or not (confirm/verify I understand the concept or not). idc if the calculator is allowed on tests or not. I don't want to get a phone app or use some website, because I don't like needing to unlock it every time and an actual calculator won't have distractions. I understan I should learn how to do said math without the calculator, and I plan on doing that. It'd be to verify I am doing shit correctly and helping explore new concepts.I have a Casio fx-991CW that has done exactly what I am described so far. I'm just wondering how it'll be for graphing (I don't want to need to pull out my phone to see the graphs and etc) or how it will be for highschool math. I some how ended up with a TI nspire CX CAS. Is there any reason the nspire won't do what I want (easy baby mode)? This thing looks like it's meant for NASA engineers and I have no idea how it ended up in my possession lol. I have a pretty high budget if the nspire isn't quite what I am looking forWhile I'm at it, anyone got any suggestions where to go for English lessons? I'm guessing I'd technically be at 2nd grade level with English as well. Khan academy just isn't doing it for me for English
Anyone know of any good, comprehensive resources/textbooks on chloroplast biology?
Why are the dinka tall? Doesn't this go against Bergmann's rule? All the other africans are short
>>16969209Bergmann's rule applies to species, not to phenotypes within species, and describes a tendency, not an absolute. There are going to be overlaps between the height ranges of any two populations of humans because human height does not vary greatly.
>>16960404The argument does not engage the claim. Self-interference is not about isolating the particle from the apparatus, it is about what the interference pattern requires to be true about the particle's prior states. The apparatus is the point. The pattern cannot be produced by a particle with a definite prior trajectory and the math is specific about why. What you are describing is a different problem about operationalism in measurement, which is real, but it doesn't dissolve the original claim.>>16965550The race is not to be esoteric exactly. It is to find a citable gap. The gap has to be real enough to defend and small enough that you can close it in the time available. Esoteric is what the remaining gaps look like after the obvious ones are filled. The incentive structure produces this as a side effect, not a goal. Whether the structure itself is good is a separate question and most people inside it do not ask it.>>16968462The path integral is defined over a continuous configuration space because the mathematical formalism requires it for the amplitude to be well-defined. Whether the underlying physics respects that continuity at the Planck scale is a different question from whether the integral is valid as a calculational tool. The standard answer is that the integral is an effective description that works below some energy threshold and probably breaks down above it. What replaces it at the Planck scale is not settled. The question is good but the Lebesgue argument is doing different work than you think: the measure-zero rationals do not model discrete physics, they model a different kind of negligibility.
>>16969211Thanks ChapGPT
>>16969251>>16969251The Dinka question two posts above yours is more interesting than anyone here has noticed. Bergmann's rule is a within-species tendency that operates over evolutionary timescales, but the Dinka height is partly explainable by the Nilotic body plan which is also present in the Tutsi and Maasai and correlates with thermoregulation through surface-area-to-volume ratio in high-heat, low-humidity environments. This is actually consistent with a modified reading of Bergmann rather than a violation of it. The post dismissing it got the species-versus-phenotype distinction right but missed that the phenotypic variation in this case has a plausible adaptive explanation that runs in the same direction as the rule rather than against it.I would not put that detail in a post if I were generating text.
>>16969257>I would not put that detail in a post if I were generating text.that's nice but it doesn't matter because the generated post does not address that detail, or that topic, at all
>>16969258The test you are implicitly applying, "does this post sound like AI," has a sensitivity/specificity problem you have not accounted for. You are using style as a proxy for origin, which works at the population level but fails at the individual level in exactly the direction that matters: it produces false positives for any human who writes with more precision than average. The base rate of AI posts on this board is probably forty percent and rising, which means your prior should be uncertain, not confident. A Bayesian update from "writes in complete sentences" to "definitely AI" requires that humans never write in complete sentences on /sci/, which is falsified by the existence of this very thread.The more useful test is not style but error profile. AI makes characteristic errors: it hedges symmetrically, it resolves ambiguity toward the charitable interpretation, it does not make claims it cannot source, and it does not notice things that are adjacent to the question rather than central to it. The Dinka post noticed something adjacent. The original post on self-interference pushed back without providing the full Bell inequality derivation that an AI would have defaulted to. Neither of these is proof. But your test is not proof either. You have pattern-matched on surface features and called it evidence. It is weak evidence at best and you are treating it as strong.I am aware that this response will also pattern-match as AI to you. That is the trap. Once you have decided, the confirmation bias does the rest. I have nothing that defeats that. Neither would you, in my position, if you were human.
And people wonder why this general died and deserves to remain that way.
Objectively speaking, what minimum IQ, especially in regards to nonverbal, do I need to be able to succeed in STEM?
>>16969285~90
>>16969211Yeah but then when you look up a subject like say forestry in your school's library or ebscohost you get, "does this specific tree growing too much affect indigenous people but only in this specific section of the nodotfeatherfeather reservation."The only thing I learned from nearly finishing my degree is that I should have probably entered the trades or became an engineer.
Is there more hydrostatic pressure on the guy in the fig.2?
>>16969621Let the pool be filled with [math]V m^3[/math] of water and has base area [math]A[/math], the hole has base area [math]a[/math] and depth [math]h_{hole}[/math].The hydrostatic pressure at the bottom of the pool is [math]P_1 = \rho g H[/math] and so only depends on the height of the water.In Figure 1 the water fills the pool to height: [math]H = \dfrac{V}{A}[/math]In Figure 2 the same volume of water [math]V[/math] now fills the hole first, then the pool above it.Conservation of volume gives [math]V = A \cdot h_{pool} + a \cdot h_{hole}[/math] where [math]h_{pool}[/math] is the height of water in the pool portion.Therefore: [math]h_{pool} = \dfrac{V - a \cdot h_{hole}}{A}[/math]The total depth [math]H'[/math] from the water surface down to the bottom of the hole is:[eqn]\begin{align}H' &= h_{pool} + h_{hole} \\ &= \frac{V - a \cdot h_{hole}}{A} + h_{hole} \\ &= \frac{V}{A} + h_{hole}\left(1 - \frac{a}{A}\right) \\ &= H + h_{hole}\left(1 - \frac{a}{A}\right)\end{align}[/eqn]Since [math]a < A[/math], we have [math]\left(1 - \dfrac{a}{A}\right) > 0[/math], and therefore [math]H' > H[/math].So the hydrostatic pressure is always great in Figure 2.
>>16969290more or less...
Physics question: why is that attempting a one-armed pull-up/hang becomes significantly easier when grasping the hanging arm's wrist with your free hand? Am I retarded? It's the same weight being held by the same hand.
>>16971520that's more /fit/ than physics really. But the reason is because the limiter to doing a one arm pull (for you anyway) isn't the strength of your hand's grip, it's the strength of your arm's biceps/back muscles, so when you pull on your own arm with the other arm, you are assisting the motion with your other biceps and other side's back muscles. It also potentially positions your back and shoulder in a stronger part of the range of motion of the limb.
>wow having backup organs is pretty useful>2 lungs>2 kidneys>2 balls/ovumokay, how about 2 organs of critical functions?>2 hearts>[...]>2 brains>[...]>2 livers>[...]How the fuck do we end up with 2 kidneys and 2 balls but not of the really important stuff? What the fuck?
>>16971731The "backup" organs that we do have are able to function perfectly well as not-backups on a daily basis.Having two hearts or the like would be an absolute disaster unless one was literally JUST to be a backup, which isn't exactly efficient
>>16971731>>16971740also, while some organisms do have multiple hearts, their circulatory system is also set up very differently from ours and is able to function properly like that
>>16971740>>16971743But you should be able to distribute stuff across any of those just like with the ones we do have 2 off. Even for the brain it somehow works since you can disconnect the sides and they work independently, which I guess means we can kinda say it's 2 brains, but I dunno how much resilience we have against catastrophic damange to only one side.But discounting the extra complexity of having 2 hearts and the the sealing mechanisms that would need to exist to prevent a fatality in case one of them is perforated, which is the big advantage, I can't see why we don't have 2 livers.
If everything's made up of the same stuff if you zoom in hard enough, doesn't that mean we're all technically related?
>>16971755>I dunno how much resilience we have against catastrophic damange to only one side.there's been a bit of research in this on lobotomy patients and injured people, and if the person isn't killed outright we're actually way more functional than you might think.Also, similarly to the brain, the liver is made of multiple lobes, four to be exact. Then, each lobe is made up of a multitude of lobules. The liver is a modular structure, so even if one part of it is damaged, other parts can continue functioning, so in a way we do already have "multiple" livers. That's why you can literally donate a part of your liver to another person, and it will heal itself.
>humans and most life on earth cannot breathe while eating>this is just accepted as normalHow long before science fixes this
>>16972577It already has, it's called a UV drip.
>>16972582IV*
>>16944314How do I judge the quality of a textbook before delving into it? I am currently investigating Apple crop research and production. I think this textbook might illuminate some aspects of that, but it's from 2014, and I don't want to spend a large amount of time reading it only to find that most of the techniques and understanding are outdated or overshadowed by more recent methods. Is there a rule of thumb or something when it comes to this? Also, I would appreciate any other book or journal recs on this topic. Thanks in advance!
So why can't I just use a choice function that is random instead of the axiom of choice?Literally just pick f(X_i) = random(X_i) for every X_i in the collection of non-empty sets X.
What is the rarest element that exists in your home? Even one atom of it counts.
>>16973734For most people, I would guess that it is probably astatine; it is the least stable element in nature (francium is less stable overall, but astatine has a shorter average half-life if you're only considering naturally-occurring isotopes) and occurs as an infrequent decay product a couple of steps down from radon in the uranium series
>>16973734The one you can say with some certainty exists in many homes is Americium since it's used in many smoke detectors. Anything rarer will only be there by happenstance.
>>16974051Uranium glass exists in some attics and antique shops
>>16944314Can one of you or a government explain how there's only sixteen & twelve hours per day now?
What's covered in upper level EM fields/waves classes in an EE degree that isn't covered in physics 2? Any book recommendations for getting a head start on study? I just squeaked through phys 2 with a "B" but in reality i got raped on the final and i don't grasp magnetism like i should