Anonymous at Thu, 13 Feb 2025 19:43:29 UTC No. 16585036

>>16584917
Any anon got the PDFs of the Trivium by Verbitsky?

Anonymous at Fri, 14 Feb 2025 00:07:02 UTC No. 16585296

>>16583878
I'm this anon, waiting on the other kind anon to help

Anonymous at Fri, 14 Feb 2025 03:09:27 UTC No. 16585401

Is there a specific nerve i can easily sever that will make me permanently lose my ability to speak?

Anonymous at Fri, 14 Feb 2025 13:09:56 UTC No. 16585716

i would like to do a relatively pure psilocybin/psilocin extraction but every tek i found online leads to an impure mush. where can i find a good, reliable method?

Anonymous at Fri, 14 Feb 2025 13:48:20 UTC No. 16585730

>>16585716
What about doing own research? I can only tell you where to order pure 4-ho-det.

Anonymous at Fri, 14 Feb 2025 13:50:26 UTC No. 16585732

>>16585716
You don't want to google, but duckduckgo.
Also shroomery and DMT-nexus

Anonymous at Fri, 14 Feb 2025 14:59:02 UTC No. 16585756

>>16585730
chemistry has a very high entry level. you need many years before you can look at a compound's skeletal structure and be able to tell what you can do with it
>>16585732
neither of those have a working tek nor even attempt to write about pure product extraction

Anonymous at Fri, 14 Feb 2025 15:08:45 UTC No. 16585761

>>16585756
I have grade school chemistry and I already know I just need to look out at solubility in solvent I want to use, possibly working with more solvents, some to dissolve trash and some to dissolve substance, then get only what dissolved substance separated from what dissolved trash, and evaporate only solvent which has non-trash in it. Maybe you need to get substance from one solvent to another, by mixing something else into one of solvents, to push out your desired thing to your solvent. You can find solubility sheets online.

Or just get some info on column chromatography.

Anonymous at Fri, 14 Feb 2025 15:10:02 UTC No. 16585762

>>16585761
I forgot to mention, sometimes you can mix in substance, so you'll create perciprate of something and separate it in filter.

They learned me all this in grade school.

Anonymous at Fri, 14 Feb 2025 15:15:02 UTC No. 16585766

>>16585756
If you really have that much excess mushrooms, rent a supercritical CO2 extractor.

Anonymous at Fri, 14 Feb 2025 17:18:19 UTC No. 16585855

>>16585296
>>16583878
The first thing you tried does not quite work, because unions are different from intersections.
You take [math]y \in f(\cup_\alpha A_\alpha)[/math], so there is some [math]x \in X[/math] such that [math]y=f(x)[/math], as you say, but now you only know that [math]x \in \cup_\alpha A_\alpha[/math], so you don't know which [math]A_\alpha[/math] [math]x[/math] is in.
Previously, you knew that [math]x\in \cap_\alpha A_\alpha[/math], so that for each [math]\alpha[/math], [math]x \in A_\alpha[/math], but now, you only know that it's in one of the [math]A_\alpha[/math], as opposed to being in all at the same time.
So, you get some particular [math]\beta[/math] with [math]x \in A_\beta[/math].
Then of course [math]y=f(x) \in f(A_\beta)[/math], and since [math]\beta[/math] is one of the [math]\alpha[/math]'s, you also get that [math]y \in \cup_\alpha f(A_\alpha)[/math], which shows that [math]f(\cup_\alpha A_\alpha) \subseteq \cup_\alpha f(A_\alpha)[/math].
To show that in fact [math]f(\cup_\alpha A_\alpha) = \cup_\alpha f(A_\alpha)[/math], you'd still need to show the other inclusion.

For the proof that [math]\cap_\alpha f(A_\alpha) \not \subseteq f(\cap_\alpha A_\alpha)[/math] in general, you'd have to find a counterexample.
That is, sets [math]A_\alpha[/math] for some indices [math]\alpha[/math] for which the inclusion does not hold.
This can be very simple (take, for example, [math]f(x)=x^2[/math]).

Anonymous at Fri, 14 Feb 2025 17:23:43 UTC No. 16585860

>>16585401
You seem like Hamas terrorist trying to damage hostage.

Anonymous at Fri, 14 Feb 2025 17:33:45 UTC No. 16585867

If a wheel is rolling like this (radius=r) with a given velocity, what is the velocity of a point on the edge of the wheel as a function of time?

Anonymous at Fri, 14 Feb 2025 18:24:39 UTC No. 16585895

>>16585761
>>16585762
anon, bro, bruh, my brother in faith
it's not about solubility. there's hundreds of these teks out there. i want to Hofmann style purify it. i want crystals or powder, not grey mush and for this i need either a thorough guide, advanced skill in chemistry to figure things on my own or PM someone like NileRed and hope that he wants to say
the best i found was A/B extraction, using polar/non-polar solvents but the effect was still mush
>>16585766
i want to remove all the stuff that gives the nauseous/toxic effects of eating raw mushrooms

Anonymous at Fri, 14 Feb 2025 18:25:54 UTC No. 16585896

>>16585867
[eqn]
r(t)=(vt+r\sin(t))\hat{\textbf{x}}+(r\cos t+r)\hat{\textbf{y}}
[/eqn]
The [math]r\sin(t)[/math] and [math]r\cos t[/math] terms come straight from a polar transformation; we know it's a circle. We determine which axis gets which trig function via some thinking and arbitrary start conditions. I started at the top of the wheel, and thought it'd spin rightwards, so y has start at its maximum (cosine), and x has to start at 0 and increase (sine). We then need to add a flat amount to account for the wheel's movement to the x. We're looking for distance, so just multiply the velocity by the time. For the y axis, we need a constant offset so that it doesn't dip below the ground, but rather the minimum is zero. So just add r. Of course, you could define your origin at the center of the wheel to change this.
This is a graph to show you it works. Just 'play' the time value.
https://www.desmos.com/calculator/kp60qpxeqj

Anonymous at Fri, 14 Feb 2025 18:28:11 UTC No. 16585897

Let
[math]A = \begin{pmatrix}8 & -21\\ 2 & -5\end{pmatrix}\;,\; v = \begin{pmatrix}\pi^e \\ e^\pi\end{pmatrix}
[/math]
How can I calculate the limit of [math]A^nv[/math] as [math]n\to \infty[/math]? This matrix is not diagonazible

Anonymous at Fri, 14 Feb 2025 18:32:44 UTC No. 16585898

>>16585860
No it's just self harm

Anonymous at Fri, 14 Feb 2025 18:34:56 UTC No. 16585900

>>16585895
I eat dried mushrooms and never get nausea. You won't get nausea from A/B extract for sure... But you can look at some RC's vendor site and just order 4-HO-DET, and you'll have clean powder, if you just want it for personal use it's simple way to have a nice, clean trip.

Anonymous at Fri, 14 Feb 2025 18:43:45 UTC No. 16585906

>>16585897
[eqn]
A^n=\begin{pmatrix}
7(2^n)-6&-21(2^n-1)\\2(2^n-1)&7-3(2^{n+1})
\end{pmatrix}\\
A^nv=[7(2^n)-6]\pi^e-21(2^n-1)e^\pi+2(2^n-1)\pi^e+[7-3(2^{n+1})]e^\pi\\
\lim_{n\rightarrow\infty}A^nv=\lim_{n\rightarrow\infty}[7(2^n)-6]\pi^e-21(2^n-1)e^\pi+2(2^n-1)\pi^e+[7-3(2^{n+1})]e^\pi=-\infty
[/eqn]
The last step is just from the n+1 term dominating.

Anonymous at Fri, 14 Feb 2025 19:41:22 UTC No. 16585961

So the spooky part of entanglement is that the wave function collapses at a distance? How do we know it does?

Anonymous at Fri, 14 Feb 2025 19:48:52 UTC No. 16585972

>>16585961
Do you really think, that you can affect one particle and it has effect on another?

Anonymous at Fri, 14 Feb 2025 19:58:19 UTC No. 16585977

>>16585961
Do you realize that wavefunction doesn't collapse anywhere but in your head?

Anonymous at Fri, 14 Feb 2025 20:05:24 UTC No. 16585985

>>16585972
That is what some explanations of QE say.
>>16585977
I thought it meant the wave state of wave particle duality transitions to the particle state.

Anonymous at Fri, 14 Feb 2025 20:12:21 UTC No. 16585992

>>16585985
It means you placed sensor somewhere which affected dynamics of whole situation.

Anonymous at Fri, 14 Feb 2025 20:14:09 UTC No. 16585995

>>16585900
why pay extra when i have jars full of dried shrooms

Anonymous at Fri, 14 Feb 2025 20:16:18 UTC No. 16585998

>>16585995
You're gifted,...

Admire the universe for giving you such good supply.

Also, tea is sufficient for having little to no side effects.

Anonymous at Fri, 14 Feb 2025 23:02:08 UTC No. 16586121

>>16585998
tea is not convenient to carry around

Anonymous at Sat, 15 Feb 2025 01:03:58 UTC No. 16586213

>>16585897
Look up jordan canonical form, use chatgpt to help

Anonymous at Sat, 15 Feb 2025 06:32:35 UTC No. 16586380

>>16586121
A/B extraction can reach 95% purity, at that point you won't have side effect either, there's lot of articles if you duck duck go it.

Anonymous at Sat, 15 Feb 2025 12:36:28 UTC No. 16586575

>>16586213
I can decompose it as [math]\begin{pmatrix}3&7 \\ 1&2\end{pmatrix}\begin{pmatrix}1&0\\0&2\end{pmatrix}^n\begin{pmatrix}-2&7 \\ 1&-3\end{pmatrix}[/math] but it diverges apparently, or I'm doing something wrong

Anonymous at Sat, 15 Feb 2025 13:03:37 UTC No. 16586594

>>16584917
>asian AI slop
White women rule the world

Anonymous at Sat, 15 Feb 2025 15:50:01 UTC No. 16586792

Why is Steven hawking famous for unverified predictions?

Anonymous at Sat, 15 Feb 2025 16:06:52 UTC No. 16586804

>>16586575
the other guy already mentioned it diverges, what's the confusion?

🗑️ Anonymous at Sat, 15 Feb 2025 16:11:43 UTC No. 16586809

>>16586575
You're saying the eigenvalues of the matrix are 1 and 2? Doesn't that mean the matrix isn't singular? Doesn't your form mean it's diagonalizable? The middle of the matrix J should be something like [ 2 1 ; 0 2 ] or [ 1 1 ; 0 1] if it's singular

Anonymous at Sat, 15 Feb 2025 16:11:52 UTC No. 16586810

>>16584917
serious question, if this was your daughter, who would you finally give her away to?

Anonymous at Sat, 15 Feb 2025 16:14:01 UTC No. 16586811

>>16586804
The statement of the question read as follows:
>Find the equation of the line for which the sequence [math]A^nv[/math] tends to.
I figure that'd be the span of the resulting vector.

Anonymous at Sat, 15 Feb 2025 16:21:01 UTC No. 16586815

>>16586811
Assuming >>16585906 has the correct A^n, then multiply it by your vector v, then you'll get a vector, not a number

Anonymous at Sat, 15 Feb 2025 16:28:34 UTC No. 16586820

>>16586815
btw, since n is going to infinity, then A^n is basically 2^n times the matrix [ 7 -21 ; 2 -6 ]. Multiply this by v to get your line, cause the vector then gets multiplied by 2^n each time

The question wants you to know that when you go to infinity, small constants can be ignored, kinda like how (x^2 + 1)/x^3 is basically 1/x as x goes to infinity

Anonymous at Sat, 15 Feb 2025 18:09:26 UTC No. 16586928

I just noticed a NOAA dataset I'm using is going 503 on their website. I'm guessing the Trump admin is shutting it down. Are there any efforts backing up this stuff in oversea servers outside his reach? Not a fed btw.

Anonymous at Sat, 15 Feb 2025 18:59:24 UTC No. 16586976

>>16585036
They are on the archive:
>>16493957
>>16493959
https://i.warosu.org/data/sci/img/0164/75/1732621975485306.pdf
https://i.warosu.org/data/sci/img/0164/75/1732622117192313.pdf

Anonymous at Sat, 15 Feb 2025 19:40:34 UTC No. 16587043

Given the points [math]v_0=(0,0,0,0)\,,\,v_1=(1,1,1,1)\,,\,v_2=(-1,1,-1,1)\,,\,v_3=(2,1,-2,-1)[/math], how do I calculate the surface area of the tetrahedron which take these points as vertices?

Anonymous at Sat, 15 Feb 2025 19:46:47 UTC No. 16587056

>>16587043
You've got too many dimensions.

Anonymous at Sat, 15 Feb 2025 19:47:29 UTC No. 16587058

>>16587056
I'm aware of that

Anonymous at Sat, 15 Feb 2025 20:05:54 UTC No. 16587090

>>16587058
Well, context would go a long way. Without any if you must answer I'd personally just throw out the first coordinate, assuming it's time, then go from there using Heron's formula.
I'd just write "Too many dimensions" if it was on a test and ask the prof though.

Anonymous at Sat, 15 Feb 2025 20:13:06 UTC No. 16587099

>>16587090
There's no further context to the question, it's literally just that. Months past the exam, I still don't know the answer

Anonymous at Sat, 15 Feb 2025 20:30:52 UTC No. 16587125

>>16587043
Just add the surface areas of each side together.

[eqn]A = \frac{1}{2} \left(\|v_1 \times v_2\| + \|v_2 \times v_3 \| + \|v_3 \times v_1\| + \|(v_2 - v_1) \times (v_3 - v_1) \| \right) [/eqn]

Anonymous at Sat, 15 Feb 2025 20:31:57 UTC No. 16587128

>>16587125
It's in 4 dimensions. There's no cross product

Anonymous at Sat, 15 Feb 2025 20:33:04 UTC No. 16587131

>>16587128
Then take the wedge product.

Anonymous at Sat, 15 Feb 2025 20:33:37 UTC No. 16587132

>>16587043
>>16587125
Just use Pythagoras, holy shit.

Anonymous at Sat, 15 Feb 2025 20:39:50 UTC No. 16587141

>>16587043
>calculate each side length from the distance formula
>three side lengths that form a valid triangle (these all do) uniquely determine that triangle, and thus that triangle's area
>add all the areas together
???

Anonymous at Sat, 15 Feb 2025 21:45:33 UTC No. 16587242

>>16586928
it's gonna be a hilarious disaster next hurricane season when we are suddenly using 1910 tech for monitoring storms.

Anonymous at Sun, 16 Feb 2025 01:44:22 UTC No. 16587459

>>16586928
https://www.reddit.com/r/meteorology/comments/1iihl5s/backups_for_nws_and_noaa_data/

Anonymous at Sun, 16 Feb 2025 03:05:54 UTC No. 16587528

>>16585401
leave that poor dear kitty cat alone

Anonymous at Sun, 16 Feb 2025 03:15:26 UTC No. 16587535

>>16585867
the two velocities may be equal

Anonymous at Sun, 16 Feb 2025 03:29:48 UTC No. 16587545

>>16585897

Anonymous at Sun, 16 Feb 2025 03:39:03 UTC No. 16587548

>>16585906
(A^n).v is a vector
not a scalar
Jesus Christ

Anonymous at Sun, 16 Feb 2025 05:07:36 UTC No. 16587593

>>16586820
this was meant for >>16586811

Anonymous at Sun, 16 Feb 2025 06:30:45 UTC No. 16587636

>>16586811
It's the span of the limit of the unit vectors (A^n)v/||(A^n)v||

Anonymous at Sun, 16 Feb 2025 15:03:22 UTC No. 16587948

>>16585762
> They learned me all this in grade school.
They learned you in school? Why would they do that ? What is , or was, so interesting about you that intrigued them enough to want to learn you?

Anonymous at Sun, 16 Feb 2025 15:05:14 UTC No. 16587949

>>16587948
https://en.wiktionary.org/wiki/learn#Etymology_2
as ESL as it sounds, he's not actually wrong to use it that way

Anonymous at Sun, 16 Feb 2025 16:08:09 UTC No. 16588005

Why does an object's mass increase when it's moving faster? And if movement is always relative, then is the corollary of this that mass is also relative? I probably sound like a retard but this is for stupid questions and stupid questions I will ask.

Anonymous at Sun, 16 Feb 2025 16:21:13 UTC No. 16588027

>>16586380
do you know the stability of pure psilocin? will it be stable enough to "carry around"? is it something that can be easily stored?

maybe look into getting 4-AcO-DMT, which is converted into psilocin in the liver, just like psilocybin

Anonymous at Sun, 16 Feb 2025 16:22:29 UTC No. 16588029

>>16586121
>>16588027
wrong reply. im retarded

Anonymous at Sun, 16 Feb 2025 16:45:34 UTC No. 16588050

>>16588027
psilocybin is stable, psilocin is not. this makes it that much more inconvenient to extract and purify

Anonymous at Sun, 16 Feb 2025 20:12:02 UTC No. 16588386

>>16588005
In relativity there are two different quantities that have the term 'mass' in them. There is the rest mass (which never changes) and the inertial mass. In Newtonian Mechanics they are the same quantity, that is not true in relativity. It is the inertial mass (often called the relativistic mass or relativistic energy) that depends on velocity (and the observer, so yes, the inertial mass is also relative). Since the inertial mass increases as you go faster, the harder it is to accelerate an object the close it gets to light speed.

Anonymous at Sun, 16 Feb 2025 21:06:25 UTC No. 16588444

>>16588386
Would it be saying that if you had a marble on a scale, it would weigh X grams, but if you rolled the same marble on the scale so that the marble was moving, it would then show something like X + 0.000000000001 grams? For the sake of argument, let's imagine that the scale was able to show the mass with this absurd level of accuracy.

Anonymous at Mon, 17 Feb 2025 00:25:14 UTC No. 16588596

>>16568083
>>16569980
See:
>>16586976

Anonymous at Mon, 17 Feb 2025 00:28:45 UTC No. 16588599

>>16571905
If you aren't already aware, this is the source of your picture.
https://settheory.net/

Anonymous at Mon, 17 Feb 2025 02:55:56 UTC No. 16588686

>>16588444
Good question. The correct answer is complicated and depends on how you make the measurement. It also gets into the differences between special and general relativity. But essentially the mass is constant but more mass-energy means more curvature of space time which means more gravity produced.

Anonymous at Mon, 17 Feb 2025 07:30:28 UTC No. 16588903

is convergent evolution evidence that life finds a way to be alike

Anonymous at Mon, 17 Feb 2025 08:10:09 UTC No. 16588937

>>16588903
Not really. It can be explained by life just adapting to reproduce well in the circumstances. Filling enviromental niches and stuff.

Anonymous at Mon, 17 Feb 2025 08:13:43 UTC No. 16588942

>>16588903
Chess AI's that literally self-teach use openings that people have already discovered because it determined them to be good. If it works well for the situation, then it ain't gonna be the first and only time it's gonna occur

Anonymous at Mon, 17 Feb 2025 09:55:44 UTC No. 16589031

Wtf is going on here? I did the exact same thing but used the values given, what gives?

Anonymous at Mon, 17 Feb 2025 10:07:18 UTC No. 16589044

>>16588903
No, but because by the argument crabs are peak evolution.

Anonymous at Mon, 17 Feb 2025 10:30:15 UTC No. 16589064

>>16589031
It's not some 1-dimensional collision.

[eqn]400 \; \text{kg} \begin{pmatrix} 7 \; \text{km/s} \\ 0 \\ 0\end{pmatrix} + 1 \; \text{kg} \begin{pmatrix} \frac{-12}{\sqrt{2}} \; \text{km/s} \\ \frac{12}{\sqrt{2}} \; \text{km/s} \\ 0\end{pmatrix} = 401 \; \text{kg} \begin{pmatrix} v_1 \\ v_2 \\ v_3 \end{pmatrix} \\
v = \sqrt{v_1^2 + v_2^2 + v_3^2} \\
\beta = \arctan(v_2/v_1) [/eqn]

Anonymous at Mon, 17 Feb 2025 11:05:51 UTC No. 16589080

>>16589064
I can't get this to be correct even after turning the velocity into a vector quantity

Anonymous at Mon, 17 Feb 2025 12:52:53 UTC No. 16589201

>>16588686
But normally the implication of more mass is greater gravitational attraction. So if velocity increases mass then a moving object would be attracted to earth with a greater force right?

Or what if we imagine another example. Imagine you have the gyroscopic toy in picrelated. Normally it weights probably 200 grams. But now imagine you made it spinning with a gorillion rpm, so that the speed would increase the mass by ten fold and the mass became two kilograms due to special relativity (imagine it is made from a special material that can resist infinite forces so the toy is able to spin that fast without breaking apart). Then you put it on a scale, would the scale now show two kilograms instead of 200 grams?

Anonymous at Mon, 17 Feb 2025 13:39:53 UTC No. 16589229

>>16589201
Sure but ask yourself how do you 'weigh' something and what are you wanting to measure? Is it its mass or the gravity it generates?

Anonymous at Mon, 17 Feb 2025 16:20:19 UTC No. 16589313

I'm studying from Introduction to Electrodynamics by Griffiths, I don't get why he calculates the work using the force 3.12 but with opposite sign. If he is calculating the work to bring q in from infinity, and the force points exactly towards the origin (where we want to bring q in), shouldn't he calculate it using F without changing the sign?
Besides, I would expect the work to be positive, since negative work would mean that we are doing work in the opposite direction than the force, right? Where am I wrong?

Anonymous at Mon, 17 Feb 2025 16:40:44 UTC No. 16589331

>>16589313
There are a number of ways to look at it, but you could just call it convention.

Anonymous at Mon, 17 Feb 2025 17:26:07 UTC No. 16589356

>>16589201
Another weirdness is that presumably the density of the object also increases when it's moving faster? If mass is bigger but the volume stays the same, then an object also becomes denser the faster it is moving which is a weird thing to think about.

Anonymous at Mon, 17 Feb 2025 18:30:14 UTC No. 16589412

>>16589313
One charge is q, the other is -q, so -q^2

Anonymous at Mon, 17 Feb 2025 18:44:17 UTC No. 16589427

>>16589313
>>16589412
The two charges are attracted to each other. If anything, it should take Positive Work (say, +10 units) to pull them Away from each other. But the energy of a particle at infinite distance is conventionally set to be 0. This means that at the distance d or 2d (whichever you're focusing on), the energy should be negative (say, -10 units). So, -10 + 10 = 0 as expected.

The moon is captured into earths orbit, so for the same reasoning, the energy is negative so that at infinity it's at 0. An electron is captured by a proton, and so it's energy is -13.6 ev.

If you want to know the potential and kinetic energies, then you can use virial theorem - so 2T = -V - and T+V = E.

Anonymous at Mon, 17 Feb 2025 18:51:57 UTC No. 16589433

>>16589427
virial theorem is only for the moon and electron-proton hydrogen atom. For your griffith's problem, it's basically just V then. Maybe that was your confusion

Anonymous at Mon, 17 Feb 2025 18:53:01 UTC No. 16589434

How many distinct three dimensional tetris piece thingies is it possible to make with ten cubes?

Anonymous at Mon, 17 Feb 2025 18:58:01 UTC No. 16589436

>>16589434
346543 if you consider reflected versions to be different things
178083 if you consider them to be identical

Anonymous at Mon, 17 Feb 2025 23:25:10 UTC No. 16589682

What is the best or most efficient way to convert heat into electrical energy if the temperature of the heat is not high enough to run steam turbines?

Anonymous at Mon, 17 Feb 2025 23:53:15 UTC No. 16589698

>>16589682
The best contender for converting a low temp difference into work is probably a Stirling engine.

Anonymous at Mon, 17 Feb 2025 23:55:59 UTC No. 16589702

>>16589682
>>16589698
Followup, if it's a small amount of heat as well a Peltier device is much easier to use and it converts the heat directly to electricity.

Anonymous at Tue, 18 Feb 2025 01:56:27 UTC No. 16589765

>>16589682
The most efficient heat engine is the Carnot engine, so for your question, use a Carnot to perform work on a turbine, and this works for any nonzero temp difference. Issue with the carnot engine is that it moves extremely slowly. But the Carnot's max efficiency (which depends on the temp diff) is used to compare how efficient any other engine is to the optimal one.

Anonymous at Tue, 18 Feb 2025 02:40:34 UTC No. 16589809

Didn’t realize there was a dedicated general to this, so if someone could answer what I asked at >>16589497 I’d appreciate it.

Anonymous at Tue, 18 Feb 2025 02:42:48 UTC No. 16589811

>>16586928
I have a buddy in the UK who works on weather monitoring primarily in drones and balloons and does a lot of projects across the world (he’s in Kenya right now). He told me the NOAA shit has having a profound ripple effect on monitoring globally since stuff like the ARGO project is impacted. Makes my blood boil that such an objective public good for the whole world is getting gutted.

Anonymous at Tue, 18 Feb 2025 11:55:56 UTC No. 16590079

>>16589436
>346543
is prime

Anonymous at Tue, 18 Feb 2025 16:17:44 UTC No. 16590352

>>16589682
As the others have said, there are methods. What they haven't said is none of them are practical and / or generate only tiny amounts of electricity. You need a large temperature gradient to do anything useful.

Anonymous at Tue, 18 Feb 2025 16:17:45 UTC No. 16590353

Let [math]\mathcal{E}_{j}[/math] be generators of the [math]\sigma[/math] algebras [math]\mathcal{A}_{j}[/math] on the sets [math]X_{j}[/math]. Let [math](E_{j}^{k})_{k} \subseteq \mathcal{E}_{j}[/math] and [math]E_{j}^{k} \nearrow X_{j}[/math] as [math]k \to \infty[/math]. Then
[eqn]
A_{1} \otimes\, \dotsm\, \otimes A_{n} = \sigma\left(\{A_{1}\, \times\, \dotsm \times A_{n} : A_{j} \in \mathcal{E}_{j}\}\right)
[/eqn]
Why is the condition [math]E_{j}^{k} \nearrow X_{j}[/math] as [math]k \to \infty[/math] for a sequence [math](E_{k}^{j})_{k} \subseteq \mathcal{E}_{j}[/math] necessary? Can you give me a counter example?

Anonymous at Tue, 18 Feb 2025 23:08:01 UTC No. 16590841

Study and solve the system depending on the parameters [math]a[/math] and [math]b[/math].
[math]
\begin{cases}
x+y-z+t=1\\
ax+y+z+t=b\\
3x+2y+at=1+a
[/math]
I can get to [math]a=2[/math].
For [math]a=2[/math] [math]b[/math] can either be either 2 or not 2. If [math]b=2[/math], the system has infinitely many solutions with two free variables. If not, there are no solutions.
Otherwise if [math]a\neq 2[/math], [math]b\in \Bbb R[/math] and the system has infinitely many solutions with one free variable.
The thing is I also get [math]a=1-\dfrac{2z}{t}[/math] and [math]b=1+\dfrac{2z^2}{t^2}[/math].
Therefore I believe I have not arrived at a solution.
Can anyone help?

Anonymous at Tue, 18 Feb 2025 23:11:03 UTC No. 16590844

Study and solve the system depending on the parameters [math]a[/math] and [math]b[/math].
[math]
\begin{cases}
x+y-z+t=1\\
ax+y+z+t=b\\
3x+2y+at=1+a
\end{cases}
[/math]
I can get to [math]a=2[/math].
For [math]a=2[/math], [math]b[/math] can either be either 2 or not 2. If [math]b=2[/math], the system has infinitely many solutions with two free variables. If not, there are no solutions.
Otherwise if [math]a\neq 2[/math], [math]b\in \Bbb R[/math] and the system has infinitely many solutions with one free variable.
The thing is I also get [math]a=1-\dfrac{2z}{t}[/math] and [math]b=1+\dfrac{2z^2}{t^2}[/math].
Therefore I believe I have not arrived at a solution.
Can anyone help?

Anonymous at Wed, 19 Feb 2025 04:29:35 UTC No. 16591085

am I b&

Anonymous at Wed, 19 Feb 2025 06:44:46 UTC No. 16591143

>>16590844
3 equations can only solve 3 unknowns, so just choose x y and z to be your variables and a b and t to be you constant parameters. If you don't know how to do a basic linear 3 equation 3 unknown problem, look up a youtube video on it. It's simple to do, but too hard to describe without pictures to look at.

Anonymous at Wed, 19 Feb 2025 06:45:46 UTC No. 16591144

>>16590844
look up solving a system of equations, 3x3 matrix

Anonymous at Wed, 19 Feb 2025 10:48:17 UTC No. 16591291

>>16590844
I think you're supposed to solve for x,y,z,t not the other way round.

Anonymous at Wed, 19 Feb 2025 11:01:01 UTC No. 16591301

>>16590353
Because you need sets of the form X x A x X x X... in there. Take a set X and a subset A of X. Then the sigma algebra S=sigma({A}) is {0,A, A^c, X}. So for n=1 it's not necessary. If you also have a space Y and a subset B of Y with T=sigma({B}), then while they both individually generate S and T, { E x F : E in {A} and F in {B} } does not generate the product sigma algebra of S and T (because you only get {0, AxB, (AxB)^c, XxY }, while XxB should be in there as well, for example).

Anonymous at Wed, 19 Feb 2025 11:57:21 UTC No. 16591351

In quantum mechanics, if two observables don't commute that means they can't be measured at the same time. What does that mean?
Imagine we have two entangled particles and we measure in 1 the spin in the x-axis and in 2 the spin in the z-axis with a Stern Gerlach experiment. According to quantum mechanics, this is forbidden.
What happens then? Does the universe collapse? Do we get both up and down measurements at the same time?

Anonymous at Wed, 19 Feb 2025 12:14:02 UTC No. 16591361

>>16591351
>What does that mean?
It means that there are no experiments which can measure both those observables at the same time. This follows from the fact that any measurement is just an entanglement of the particle with a macroscopic observable.
>measure in 1 the spin in the x-axis and in 2 the spin in the z-axis
These are commuting observables.

Anonymous at Wed, 19 Feb 2025 14:43:25 UTC No. 16591448

1.If the galaxy expands faster than the speed of light, does that mean there is a boundary beyond which gravity cannot exercise any effect on us? I dont mean 10^-9999999999, but exactly 0 m/s^2?

2.Apparently the furthest galaxy that we can observe is 33.6 billion light years away (JADES-GS-z13-0). If we assume an empty space with two atoms hydrogen, separated by 33.6 billion years, will be drawn to each other by gravity? (after it reaches them, regardless how negligent it is?)

Anonymous at Wed, 19 Feb 2025 15:50:19 UTC No. 16591496

>>16591351
> According to quantum mechanics, this is forbidden.
It is not forbidden however the result is uncertain because fundamentally you can't measure two things at once. In the math of quantum mechanics this is expressed as acting with each operator in order, but for operators (observables) that don't commute the order matters: [math]\hat{S}_{x} \hat{S}_{z}|\psi\rangle \neq \hat{S}_{z} \hat{S}_{x}|\psi\rangle[/math]

So if you try and make this "dual measurement" there is an uncertainty in what answer you will get.

Anonymous at Wed, 19 Feb 2025 16:02:37 UTC No. 16591515

>>16591448
1. theoretically yes because gravitational waves also travel at the speed of light
2. see above

Anonymous at Wed, 19 Feb 2025 16:48:48 UTC No. 16591562

Even on this board I get censored lol.
https://warosu.org/sci/thread/16590818
Asking about statistical methodology was too much... deleted after 12 hours.

Anonymous at Wed, 19 Feb 2025 16:52:55 UTC No. 16591568

>>16591562
Btw, apparently the "trick" is called Everest regression:

>An Everest regression is what you get when you decide to control for an essential characteristic of the thing you’re interested in; ‘controlling for height, Mount Everest isn’t that cold’.

https://marginallyproductive.com/2020/06/14/the-everest-regression

But there is complete plausible deniability. There is nothing technically wrong. It is basically a means of obfuscation.

Anonymous at Wed, 19 Feb 2025 22:14:19 UTC No. 16591890

>>16591562
>>16591568
My german is poor, so I didn't read the paper, but from what I could gather from your posts: it's not quite the same thing, since the paper is trying to ascertain a causal relationship, while the everest example is just a poorly specified model.
If you're interested in whether *being a migrant at all* has an effect on one's propensity to crime, you want to control for any confounders, such as age.
(Maybe being young makes you more likely to be a migrant and more likely to commit a crime. Then simply regressing crime on `dummy_migrant` makes any causal interpretation basically impossible because you're unable to separate what `dummy_migrant` implies about the crime_rate, and what `dummy_migrant` tells you about age+what age tells you about the crime rate.)
In abstract terms, if you have a causal DAG with X (migrant) maybe influencing Y (crime rate), and variable(s) Z influencing both X and Y, you're only interested in the effect from X to Y directly (i.e. not its confounding effect through Z). Controlling on Z makes this possible.

In the everest example, this is different. If you're interested in whether mount everest is cold at its peak, there's no reason to control for height, because this has no causal link to *being mount everest* (in this case there's no reason to perform a regression at all, I would say, so the example is not perfect).
If you control for height anyways, you then could see that the coldness is fully explained by the height, but if you're not careful you might not look at the control variables' coefficients, and misinterpret "mount everest's peak is not cold" because the constant term or the coefficient of `dummy_everest` or whatever is approx. zero or the average temp on earth or ...

>I get censored
>But there is complete plausible deniability. There is nothing technically wrong. It is basically a means of obfuscation.
Schizobabble.

Anonymous at Thu, 20 Feb 2025 01:03:33 UTC No. 16592017

For the area enclosed by the curves y=0, y=8, and y=x^(3/2) we can find a solid of revolution using the shell method with the expected volume being equal to 192pi cubic units. When we integrate in terms of y with the integrand as 2pi y(y^(2/3)dy with upper limit y=8 and lower limit y=0 we find the correct volume. When we integrate with the integrand 2pi x(8-x^3/2)dx with upper limit x=4 and lower limit x=0 we find a value that is off from the correct volume by a multiplication exactly equal to (volume found)(7/2). What is a general method to arrive at the scaling factor for any solid of revolution problem so we may choose to integrate with respect to either variable and find the correct volume?

It may be helpful to notice that when only finding the area under the curve for the integral y=0 to y=8 (y^2/3)dy area found is equal to area found by the integral x=0 to x=4 (8-x^3/2).

Anonymous at Thu, 20 Feb 2025 01:36:07 UTC No. 16592043

>>16591890
While this seems plausible, the problem is the overall framing. Their conclusion generalizes that "there is no causal link between migration and higher crime rates." But if we view the demographic composition - being predominantly young males - as an inherent and inseparable feature of recent migration in Europe, then this framing is obfuscating. There is a semantic jump from *being a migrant at all* to *migration in general*.

Crémieux seems to agree with me, commenting on this study:

>{Controlling for the quality of ingredients, preparation, location, meals, staff, and atmosphere} McDonald's is indistinguishable from a five star restaurant.

https://x.com/cremieuxrecueil/status/1892279616171041182

Anonymous at Thu, 20 Feb 2025 02:20:28 UTC No. 16592069

You have a closed loop (like a rubber band) which is always one unit long. No matter which shape the loop is in, it can always fit inside the region A. What is the minimum area of region A?

Anonymous at Thu, 20 Feb 2025 02:55:59 UTC No. 16592099

>>16592069
A circle is the smallest A if I understand the question correctly, so pi times a quarter the unit quantity squared, or pi/16 units squared.

Anonymous at Thu, 20 Feb 2025 03:37:42 UTC No. 16592120

>>16592099
But how do you know it can't be smaller?

And to clarify. The loop can be rotated to make it fit. So the same shape rotated to different angles counts as the same loop.

Anonymous at Thu, 20 Feb 2025 07:04:11 UTC No. 16592238

>>16592069
You can't define any area because you have only defined the length of the band, it has zero width until you give us one.

Anonymous at Thu, 20 Feb 2025 07:48:36 UTC No. 16592268

>>16592069
https://en.wikipedia.org/wiki/Moser's_worm_problem

Anonymous at Thu, 20 Feb 2025 07:49:07 UTC No. 16592269

>>16592017
There's no scaling factor. If your factor isn't equal to 1, then you're doing two different problems (can you figure out which physical problem they correspond to?). If you want to do a variable change, then, just do a variable change as you normally would in calculus, so for you just dy = (dy/dx) dx, kek.

Anonymous at Thu, 20 Feb 2025 08:30:40 UTC No. 16592299

>>16592043
Well, sure. Unless I've misunderstood all this time, the argument of a migrant-skeptic isn't "we should be wary because they commit crimes at roughly the same rate as the native young male population" (probably because this isn't true), but it's what your semantic jump amounts to (assuming they only controlled for age and gender, again, I didn't read it).

Maybe this is clearer in your examples: say you read "controlling for height, mount everest isn't very cold" as a headline somewhere. You'd hope no one gets the idea that "mount everest's peak is not that cold", and, being somewhat statistically conscious, you decide to look at the study, and notice the significant coefficient in front of `height`.
What this tells you is that 1) the headline is shit, and 2) the coldness is very well explained by the height of the peak.
(There's a lot more you should still investigate before trying to draw any conclusion from the regression, but that's beside the point.)
Similarly, if you read "controlling for ingredients, preparation, location, meals, staff, and atmosphere, mcd's is a good restaurant", you should draw similar conclusions; the quality of the restaurant is probably thoroughly explained by "ingredients, preparation, location, meals, staff, and atmosphere".

>cremieux on twitter
Who? What?

Anonymous at Thu, 20 Feb 2025 09:26:29 UTC No. 16592349

>>16584917
how can i get a real STEM degree that I can put on my resume without amassing big debt?
i found OSSU open source CS cirriculum, but even if i do all of this, I wont get the fancy piece of paper.

Anonymous at Thu, 20 Feb 2025 10:18:59 UTC No. 16592430

How do I do well on my controls course? Its so fucking hard. I've spent more time on it than all other courses but it still looks like Greek to me. I'm not even a quarter of the way through the semester and I already know I'm failing.

🗑️ Anonymous at Thu, 20 Feb 2025 20:13:53 UTC No. 16593681

Why is it so counter-intuitive to think that A percent of B is always the same as B percent of A? Like imagine you're cooking or something and you take 17% from three 30 grams of salt. Then that would be the same as taking 30% of 17 grams of salt. Why can't I understand this?

And I know you can do algrebraic trickery like A% of B = (A/100)*B = (A*B)/100 = (B*A)/100 = (B/100)*A

How can you see this without math?

Anonymous at Thu, 20 Feb 2025 20:17:47 UTC No. 16593693

Why is it so counter-intuitive to think that A percent of B is always the same as B percent of A? Like imagine you take 17% from 30 liters of water. Then that would be the same as taking 30% of 17 liters of water. Why can't I understand this?

I know you can do algrebraic hocus pocus like A% of B = (A/100)*B = A*(1/100)*B = (B/100)*A

How can you understand this without algebra?

Anonymous at Thu, 20 Feb 2025 21:52:40 UTC No. 16593940

>>16593693
it's because the relationship is inverse. if A is 4/10 of B which is 40% then B is 10/4 of A which is 250%
different approach would be to think that A and B represent an amount (or mass or whatever) and 4 lots of B are equal to 10 lots of A therefore to make them equal you have to increase A by a factor of 10/4 (250% of it) or decrease B by 4/10 (40% of it)

Anonymous at Thu, 20 Feb 2025 23:05:19 UTC No. 16594060

>>16593693
>why is it counter-intuitive
Because the fact that multiplication and division numbers commute isn't perfectly intuitive. Take one square block, double it, then cut that rectangle in half, and you end up with the same block. Take the original square block, cut it in half, then double that half block, and you end up with the same block. Is it the same if you do it with 3 instead of 2? Is it the same if you do it with pi instead of 2? On the other hand, multiplying two numbers commutes is very easy to understand since a 2x3 rectangle has the same area as a 3x2 rectangle, or any other positive numbers. Is multiplying 3 numbers intuitive? Sure, just go to 3D. Is it intuitive that this works multiplying 4 numbers? You can't see 4D, so no, but you trust the simple cases.

For intuition, you basically accept the proof the division and multiplication don't care about order and move on. You focus on the simple cases, and trust them to extend the rule to less intuitive objects.

Anonymous at Thu, 20 Feb 2025 23:06:25 UTC No. 16594062

>>16594060
>2x3 rectangle has the same area as a 3x2 rectangle...
(why? Just rotate your head)

Anonymous at Thu, 20 Feb 2025 23:51:39 UTC No. 16594139

>>16593693
just ignore the percent.
giving 17 people 30 liters of water each is clearly the same as giving 30 people 17 liters of water each. lets say you took that water from a tank that holds 1000 liters. what proportion of the water did you use?
in the first case:
[math] \displaystyle
\frac{17 \times 30}{1000}
[/math]
in the second case
[math] \displaystyle
\frac{30 \times 17}{1000}
[/math]
you used the same *amount* of water in both cases, so you clearly used the same *proportion* of water in both cases.

Anonymous at Fri, 21 Feb 2025 00:11:30 UTC No. 16594174

>>16592349
spend a year lifting boxes in upstate NY, apply for residency, then apply to SUNY/CUNY. alternatively, CA WA or TX state schools.
then scholarshipmaxx and get a part time gig weekends

Anonymous at Fri, 21 Feb 2025 01:49:11 UTC No. 16594288

>>16594139
Do it without numbers and symbols

Anonymous at Fri, 21 Feb 2025 01:59:30 UTC No. 16594299

>>16594288
if half of all people in a room have a cookie, thats the same amount of cookie as if all people in a room have half a cookie.

Anonymous at Fri, 21 Feb 2025 04:49:11 UTC No. 16594435

>>16594299
Like this silly

Anonymous at Fri, 21 Feb 2025 06:53:48 UTC No. 16594496

What's your best anti-aging book?

Anonymous at Fri, 21 Feb 2025 09:38:39 UTC No. 16594595

>>16593693
>How can you understand this without algebra?
>17% from 30
This is the amount you want.
>30% from 30
You now have 30/17 times too much water, so you must decrease total amount by 17/30.
>30% from 30 * (17/30)
How convenient. That's just 17.
>30% from 17.
Done.

Anonymous at Fri, 21 Feb 2025 10:05:49 UTC No. 16594616

>>16593693
1. The proportion between two numbers is the factor by which you need to multiply the second number to get the first
2. The inverse proportion is the factor by which you need to multiply the first number to get the second
3. If you multiply the first number by the inverse proportion, and the second number by the proportion, they swap places
4. To maintain the same relative amount, when you scale the percentage by a factor, you have to scale the total amount by the inverse factor
5. Consider the proportion of the percentage to the total amount
6. You scale the percentage by this proportion
7. You scale the amount by the inverse proportion
8. The number swap places
9. The relative amount remains the same

Anonymous at Fri, 21 Feb 2025 14:12:10 UTC No. 16594812

>>16585855
Ok, so to show that [math]\cup_\alpha f(A_\alpha) \subseteq f(\cup_\alpha A_\alpha)[/math] then I need to show that [math]y \in \cup_\alpha f(A_\alpha)[/math] is also in [math]f(\cup_\alpha A_\alpha)[/math]. So if [math]y \in \cup_\alpha f(A_\alpha)[/math] then there is an [math]x \in A_\alpha[/math] such that [math]y=f(x)[/math]. It follows that [math]y \in f(\cup_\alpha A_\alpha)[/math] because [math]x \in A_\alpha[/math] is also in [math]\cup_\alpha A_\alpha[/math].

[eqn]\text{Using } f(x) = x^2 \text{ to show that } \cap_\alpha f(A_\alpha) \nsubseteq f(\cap_\alpha A_\alpha).
\\
\textbf{A} = \left\{ p,q,r \right\}
\\
A_p = \left\{ -3,-2,-1,0,1,2,3 \right\}
\\
A_q = \left\{ 0,1,2,3 \right\}
\\
A_r = \left\{ -3,-2,-1 \right\}
\\
f(A_p) = \left\{ 0,1,4,9 \right\}
\\
f(A_q) = \left\{ 0,1,4,9 \right\}
\\
f(A_r) = \left\{1,4,9 \right\}
\\
\cap_\alpha f(A_\alpha) = \left\{ 1,4,9 \right\}
\\
f(\cap_\alpha A_\alpha) = \emptyset
\\
\therefore \text{ } \cap_\alpha f(A_\alpha) \nsubseteq f(\cap_\alpha A_\alpha).[/eqn]

I can probably show that for arbitrary indexed family of sets with disjoint subsets that have intersecting image sets but maybe when I get bored sometime.

Anonymous at Fri, 21 Feb 2025 16:45:00 UTC No. 16595040

>>16594435
Eudoxus

Anonymous at Fri, 21 Feb 2025 21:00:08 UTC No. 16595436

>>16584917
>stupid
Do astronomers still use a Julian calendar?

Anonymous at Fri, 21 Feb 2025 21:48:35 UTC No. 16595496

>>16595436
No.

Also it's stupid as in simple, not stupid as in retarded.

Anonymous at Fri, 21 Feb 2025 22:00:54 UTC No. 16595512

>>16595496
What is Julian epoch J2000.0, then?

Anonymous at Fri, 21 Feb 2025 22:22:51 UTC No. 16595549

>>16595512
Despite the name that has nothing to do with the Julian calendar. A Julian year is just a definition of time.

Anonymous at Sat, 22 Feb 2025 03:15:35 UTC No. 16595885

So how many is it?

Anonymous at Sat, 22 Feb 2025 04:29:02 UTC No. 16595925

>>16595885
it can't be that hard to calculate, right? it's related to the birthday paradox

Anonymous at Sat, 22 Feb 2025 04:36:46 UTC No. 16595928

>>16586810
the blossom samurai

Anonymous at Sat, 22 Feb 2025 04:39:41 UTC No. 16595930

>>16586810
sweet home Alabama

Anonymous at Sun, 23 Feb 2025 17:06:38 UTC No. 16597423

I was told that the most important theorem in physics was discovered by a woman. Is that true?

Anonymous at Sun, 23 Feb 2025 19:35:09 UTC No. 16597547

>>16597423
i believe this is what you've been told about
https://en.wikipedia.org/wiki/Wu_experiment

Anonymous at Sun, 23 Feb 2025 19:36:29 UTC No. 16597549

>>16597423
> the most important theorem in physics
That's subjective. How is that judged? Anyway, assuming they were talking about Noether's theorem, then it is certainly in contention. It's a key component of the Standard Model and tells us how fundamental conservation laws and fundamental properties like energy and momentum exist.

Anonymous at Sun, 23 Feb 2025 21:20:23 UTC No. 16597629

I have three travel blankets I purchased at a trucker gas station, they're great but made of some kind of plastic fiber. I've noticed the fibers shed and I'm pretty sure they're getting into my eyes and lungs, they're certainly in my hair and all over surfaces. I know the lungs are not very good at clearing things like that out, so what's an effective method to de-plastic my body? One thought was inhaling steam to attempt to trap and cough it up.

Anonymous at Sun, 23 Feb 2025 21:23:02 UTC No. 16597634

>>16597629
Here's a pic of one said fiber, it's about average length from my observations. I found this one stuck to my skin.

Anonymous at Mon, 24 Feb 2025 01:12:34 UTC No. 16597848

Watching a youtube video made me think of an interesting physics problem. You have a bugatti which weighs 1995 kilos and it goes 1/4 miles in the time of 9.6 seconds. Then I wondered what is the minimum number of horsepowers by which this could be achieved assuming there was no energy loss?

I figured that the power would have to be constant the the whole time (in which case acceleration would not be constant). So just assuming constant acceleration and finding the horsepowers that way is not going to give the right answer (in fact I already did it in this way and got 978.5 hp).

Anonymous at Mon, 24 Feb 2025 07:41:20 UTC No. 16598049

>>16597848
> the power would have to be constant the the whole time (in which case acceleration would not be constant)
I don't believe that is true:
[eqn]P\cdot t = \frac12 m v^2 \\
v = \sqrt{\frac{2 \cdot P \cdot t}{m}} \\
a = \frac{dv}{dt} = \sqrt{\frac{P}{2m\cdot t}}[/eqn]
Since you know P, m and t and they are fixed then so is a (though in a real car the mass would change as you used fuel).

Anonymous at Mon, 24 Feb 2025 08:43:01 UTC No. 16598084

Are there any resources that I can use to test my knowledge? I feel as if the problems in our given Linear Algebra compendium are useless, as I have memorized the solutions. What about that brilliant website I keep seeing youtubers shill? I'm pretty desperate to succeed.

Anonymous at Mon, 24 Feb 2025 09:48:52 UTC No. 16598101

How do you do this limit?

Anonymous at Mon, 24 Feb 2025 13:05:07 UTC No. 16598236

>>16598101

Anonymous at Mon, 24 Feb 2025 13:19:53 UTC No. 16598254

I'm writing scifi and making a stealth missile for use in space. It accelerates to high speed from outside detection range so it is not emitting thrust as it approaches the target. Could a missile maneuver itself in space by having an internal ballast tank with a pump that throws a liquid in the opposite direction of intended maneuver then recapturing the liquid and repeating the process as needed? Assuming the pump is directly connected to the missile's frame. Would size(of the missile) matter? Would using mercury instead of water matter?

Anonymous at Mon, 24 Feb 2025 13:25:53 UTC No. 16598260

>>16598254
Capturing it would revert the momentum change which would seem to defeat the purpose.

Anonymous at Mon, 24 Feb 2025 13:30:30 UTC No. 16598267

>>16598260
Okay, so I can just shoot it out into space and have a limited amount of maneuver, thanks! I assume due to weight and temperature mercury would be more efficient?

Anonymous at Mon, 24 Feb 2025 13:34:51 UTC No. 16598270

>>16598267
Not sure what you mean by temperature. In the cold of space mercury would be a solid. Just use the propulsion material / gas / liquid like a sane person.

Anonymous at Mon, 24 Feb 2025 13:41:45 UTC No. 16598278

>>16598270
Hmmm, how much gas would you need to throw to maneuver an object though? Surely this would call for an increasingly massive tank.

Anonymous at Mon, 24 Feb 2025 13:49:28 UTC No. 16598281

>>16598278
Not really. If the missile is already moving fast it would not take much reaction matter to adjust its course. Think about when driving fast, small turns of the wheel equate to large movements.

Anonymous at Mon, 24 Feb 2025 14:32:17 UTC No. 16598303

How much genetic engineering would be required to get a woman with four booba?

Anonymous at Mon, 24 Feb 2025 18:00:03 UTC No. 16598479

>solid = poop
>liquid = piss
>gas = fart
What is the plasma of above three?

Anonymous at Mon, 24 Feb 2025 18:09:21 UTC No. 16598493

>>16598049
But if you have the acceleration as a function of time, then acceleration is not constant during the time that the car is driving.

Anonymous at Mon, 24 Feb 2025 19:24:41 UTC No. 16598578

>>16598479
Taco bell sharts

Anonymous at Mon, 24 Feb 2025 20:39:59 UTC No. 16598651

For my PSET, I was asked to make a "movie" for a solution to the partial differential equation I solved. I think they just want a simple animation. But I want to do an epic cut scene of an anime girl before it goes to the animation to make my TA smile. could someone provide a webm? Also is this going to get me docked marks?

Anonymous at Mon, 24 Feb 2025 20:43:40 UTC No. 16598661

>>16598101
cross your Zs and take a non blurry picture

Anonymous at Mon, 24 Feb 2025 20:57:56 UTC No. 16598685

Babbys first math lessons here, trying to learn on my own. Can't understand how a quadratic formula can have two answers when only one will work as a solution (I understand that the formula produces 2 solutions for x depending is it positive or negative etc).
Like in 2x^2+x=6, the formula says x=1.5 or -2 but only 1.5 works here?
Is it just that the formula has two answers and the equation has only one?
Sorry for any stupid mistakes, I am pretty retarded.

Anonymous at Mon, 24 Feb 2025 21:05:01 UTC No. 16598694

>>16598685
-2 squared equals 4, not -4. both solutions work.

Anonymous at Mon, 24 Feb 2025 21:07:26 UTC No. 16598696

>>16598694
Thanks, all calculators I tried gave the wrong answer but most certainly it was my fault.

Anonymous at Mon, 24 Feb 2025 21:12:41 UTC No. 16598704

>>16598696
you have probably typed -2^2 instead of (-2)^2

Anonymous at Mon, 24 Feb 2025 21:21:58 UTC No. 16598710

>>16598704
Yes

Anonymous at Mon, 24 Feb 2025 21:30:06 UTC No. 16598722

>>16598493
Acceleration can't be a function of time since anon stated the power is constant.

Anonymous at Mon, 24 Feb 2025 21:42:12 UTC No. 16598732

>>16594812
This looks right to me, good job.

🗑️ Anonymous at Tue, 25 Feb 2025 14:45:24 UTC No. 16599286

>>16598722
I don't understand. If a cat goes from zero to X mph during the 9.6 seconds time then obviously it is possible to represent its acceleration as a function of time. Doesn't matter what the power is doing.

Anonymous at Tue, 25 Feb 2025 14:47:42 UTC No. 16599287

>>16598722 #
I don't understand. If the car goes from zero to X mph during the 9.6 seconds time then obviously it is possible to represent its acceleration as a function of time. Doesn't matter what the power is doing.

Anonymous at Tue, 25 Feb 2025 16:49:37 UTC No. 16599347

Can someone help me put this in echelon form? I know the bottom row will become all zeros but I just can't seem to put it in that form. Thank you!

Anonymous at Tue, 25 Feb 2025 16:52:36 UTC No. 16599352

>>16598049
t is obviously not fixed though. It's 0 at the start and 9.6 at the end. At least that's the interpretation of it that makes your formulas correct.

Anonymous at Tue, 25 Feb 2025 18:37:56 UTC No. 16599446

>>16599287
Yes but power is directly related to acceleration. So if the amount of power is constant then so is the acceleration.

>>16599352
That just means there is a change of velocity, not acceleration.

Anonymous at Tue, 25 Feb 2025 19:24:05 UTC No. 16599479

>>16599347
https://matrixcalc.org/slu.html#solve-using-Gaussian-elimination%28%7B%7B11,-3,-9,5%7D,%7B37,31,33,-15%7D,%7B-3,5,3,-1%7D%7D%29

Anonymous at Tue, 25 Feb 2025 19:30:29 UTC No. 16599490

Anonymous at Tue, 25 Feb 2025 20:44:47 UTC No. 16599553

>>16599490
https://youtu.be/--bIyenPc20?t=5s

Anonymous at Tue, 25 Feb 2025 23:49:05 UTC No. 16599685

>>16598101
Your z's look like 2's. Fix that, or type your question else no one can read it.

Maybe turn z = a + bi or z = Re^{i\theta} and simplify, set to infinity

Anonymous at Wed, 26 Feb 2025 00:01:40 UTC No. 16599696

>>16598101
3 Z's at the bottom, 2 Z's at the top, it's probably 0. If you want to definitely make sure, use the normal complex analysis inequalities and figure it out

Anonymous at Wed, 26 Feb 2025 01:44:05 UTC No. 16599753

>>16599553
I'm not watching your ugly video.

Anonymous at Wed, 26 Feb 2025 06:31:32 UTC No. 16599949

I posted this: >>16599490

But I didn't post this: >>16599553

Anonymous at Wed, 26 Feb 2025 12:57:56 UTC No. 16600069

>>16599446
If an object is being accelerated with constant power, then velocity is not constant and neither is acceleration. You can realize that by thinking of the fact that energy is equal to force multiplied by distance (and power on the other hand is that divided by time). Any given interval of X seconds, the more time has passed from the beginning of the acceleration, the more distance is covered. So energy would also be greater. But we don't want that, we want constant power meaning that energy per unit of time stays constant. So to counteract the increased distance, we must decrease the force. And decreasing the force means decreasing acceleration. So constant power implies that acceleration is always decreasing although velocity is always increasing.

Anonymous at Wed, 26 Feb 2025 15:14:38 UTC No. 16600164

How to calculate the limit as z->inf

Anonymous at Wed, 26 Feb 2025 15:22:08 UTC No. 16600171

>>16584917
I was playing with parser combinators and I made a kind of parser combinator that parses a string and produces a string.

Is this something that has already been explored that I can read about? The implementation is a small Java library and I want to write documentation for it and I want to make sure I use the right words if words for this already exist.

The current practical application is I use it to parse a programming language I made up, and produce another string which contains an intermediate form for the program which can then be interpreted or compiled easily.

Anonymous at Wed, 26 Feb 2025 16:20:13 UTC No. 16600211

>>16600164

Anonymous at Wed, 26 Feb 2025 16:24:07 UTC No. 16600214

>>16600211
only the real part of the plot

Anonymous at Wed, 26 Feb 2025 17:46:01 UTC No. 16600253

Does anyone know how to contact Uncle Fester and/or buy his books?

Anonymous at Wed, 26 Feb 2025 18:06:59 UTC No. 16600270

>>16600253
>Uncle Fester
Do you mean J*m*s F*tz*r?
Because he's an evil liar,
and a saboteur.

Anonymous at Wed, 26 Feb 2025 18:11:18 UTC No. 16600276

>For instance, if one has a stone on the end of a string, and swings in a circle over his head, then one can find one has to pull, the reaosn is, that the speed is not changing as it goes around the circle, but its changing its direction, so there must be perpetually an in-pulling force, and this is proportional to the mass, so if we were to take two different objects, first swing one, and then swing another one at the same speed around the head and mesure the force in the second one, that second one, the new force, is bigger than the other force in the proportion that the masses are different.

>that second one, the new force, is bigger than the other force in the proportion that the masses are different.

I dun get it

Anonymous at Wed, 26 Feb 2025 18:15:42 UTC No. 16600280

>>16600164
you never said what the function z is or it's derivative

Anonymous at Wed, 26 Feb 2025 18:18:54 UTC No. 16600281

>>16600276
if the masses are diff, the forces are diff, cuz F=ma

Anonymous at Wed, 26 Feb 2025 18:27:22 UTC No. 16600292

>>16600281
why say the masses are bigger and not that they can be either smaller or bigger

Anonymous at Wed, 26 Feb 2025 19:44:19 UTC No. 16600343

>>16600292
*shrug

Anonymous at Wed, 26 Feb 2025 20:03:27 UTC No. 16600359

>>16600270
Care to elaborate? I'm talking about Steve P.

Anonymous at Wed, 26 Feb 2025 20:07:37 UTC No. 16600362

>>16597848
>minimum number of horsepowers by which this could be achieved assuming there was no energy loss?
You are trying to solve for an upper bound on the power P_max. Your horsepower is a function of time, but it can never be greater than P_max. Your maximum speed at time t is given by this post >>16598049
[math]v_{max}(t)=\sqrt{\frac{2P_{max}t}{m}} [/math]
Now integrate to find an inequality for the final distance x_f after time t_f
[math]x_f\leq \sqrt{\frac{2P_{max}}{m}}\frac{2}{3}t_f^{3/2} [/math]
Rearrange to find what your max power needs to be
[math]P_{max}\geq \frac{9}{8}m\frac{x_f^2}{t_f^3} [/math]
Now you can plug in numbers and do the unit conversions.

Anonymous at Wed, 26 Feb 2025 22:41:27 UTC No. 16600491

Can someone help me with interpreting a carbon and proton NMR? I have never done it and my biochemistry lab just hit me right away with interpreting experimental NMR spectra. I am also a foid so if you want female attention in return for that favour I would not mind. Please contact me if you can help a bitch out: antiaircraftfriend._52077

Anonymous at Wed, 26 Feb 2025 22:53:24 UTC No. 16600506

>>16600491
>if you want female attention in return for that favour I would not mind
omg
are you soliciting?
how revolting!

Anonymous at Wed, 26 Feb 2025 23:06:00 UTC No. 16600522

>>16600506
Honestly I'd do whatever just for the love of the air you breathe help me out before I make mistakes and bomb this

Anonymous at Thu, 27 Feb 2025 00:37:47 UTC No. 16600650

I'm being filtered by kinetics. Why the fuck is there like four different formulas for the same shit? What makes a first order reaction exponentially different a zero or second order reaction?

Anonymous at Thu, 27 Feb 2025 01:32:36 UTC No. 16600692

>>16600650
Be more specific with what you're talking about; kinetics could refer to at least three different fields and in one of them at least three different classes.
Are the formulas distinct or just different representations?
If the latter focus on the one you find most intuitive and rederive others as needed.
Your second question I don't know exactly what you're referring to. Depends on the reaction in question I'd think, but it sounds like brushing up on your differential equations will help.

Anonymous at Thu, 27 Feb 2025 03:36:16 UTC No. 16600759

>>16600692
I'm talking about kinetics in chemistry.
Picrel is what I'm confused about. Why does it change exponentially between different reaction orders?

Take the formula for rate law between two substances, for example:
[ math ] A + B \rightarrow product [ /math ]
[ math ] Rate = k[A]^m[B]^n [ /math ]
What do the m and n represent on a conceptual level? Why does the concentration of a substance in some reactions have an exponential impact on the rate at which a reaction occurs rather than a multiplicative impact like:
[ math ] Rate = km[A]n[B] [ /math ]

Anonymous at Thu, 27 Feb 2025 03:40:16 UTC No. 16600762

>>16600759
[math] A + B \rightarrow product [/math]
[math] Rate = k[A]^m[B]^n [/math]

[math] Rate = km[A]n[B] [/math]

Anonymous at Thu, 27 Feb 2025 04:06:48 UTC No. 16600779

>>16600759
I'm not a chemist but it's probably related to things like cross section and interaction rate.
Your textbook should have a derivation of such a thing; if not you can find them in physics books (statistical or particle physics should have them) although there will be different conventions.

Anonymous at Thu, 27 Feb 2025 04:12:17 UTC No. 16600785

>>16600491
Just curious, what book yall using?

Anonymous at Thu, 27 Feb 2025 04:31:49 UTC No. 16600792

>>16600759
It's empirical buddy. The larger the exponent, the more the rate of reaction depends on the concentration of the corresponding reactant. Not all reactions match this rate formula.

It makes no sense to say the rate is proportional to mn[A][B] since m and n commute, so there's no way to associate m and n with either [A] or [B]. An assumption with commuting numbers like this makes no logical sense. m and n can be fractions too btw. Don't think too hard about it

Anonymous at Thu, 27 Feb 2025 04:55:29 UTC No. 16600799

>>16600759
The "Integrated Rate Law" for the "1st Order" can be written like this instead:
ln([A]_0/[A]_t) = k*t

Then all three I. R. Laws feature:
+k*t

Anonymous at Thu, 27 Feb 2025 05:12:46 UTC No. 16600802

>>16600491
Maybe start here
https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Organic_Chemistry_I_(Liu)/06%3A_Structural_Identification_of_Organic_Compounds-_IR_and_NMR_Spectroscopy/6.05%3A_NMR_Theory_and_Experiment
then go on to H then C NMR, which they got pages on (6.5-6.8)

Anonymous at Thu, 27 Feb 2025 06:08:25 UTC No. 16600829

>>16600491
Post a pic of your problem

Anonymous at Thu, 27 Feb 2025 06:30:04 UTC No. 16600839

>>16600799
They're plotting f(t) = ln[A], not f(t) = ln(1/[A]) or f(-t) = ln[A]. What would be the point of that?

Anonymous at Thu, 27 Feb 2025 06:37:24 UTC No. 16600842

>>16584917
How big is the wave on the upper right of this image (taken from Soma City during Japan's 2011 tsunami before it collapses and smashes into some kind of barrier)? 10 meters/30 foot? I can see some trees but they might be shrubs.

Anonymous at Thu, 27 Feb 2025 16:31:05 UTC No. 16601103

Let [math] f:[a,b] \times [c,d] \rightarrow \mathbb{R} [/math] be a function with continuous first order partial derivatives. Define [math] F:[a,b] \times [c,d] \rightarrow \mathbb{R} [/math] as [math] F(x,y) = \int_c^y \int_a^x f(u,v) \, du \, dv [/math]. Am I correct in thinking that [math] \frac{\partial^2 F}{\partial x^2} (x,y) = \int_c^y \frac{\partial f}{\partial x} (x,v) \, dv [/math], [math] \frac{\partial^2 F}{\partial y^2} (x,y) = \int_a^x \frac{\partial f}{\partial y} (u,y) \, du [/math] and [math] \frac{\partial^2 F}{\partial x \partial y} (x,y) = f(x,y) [/math]?

Anonymous at Thu, 27 Feb 2025 17:12:08 UTC No. 16601149

sometimes i think about plugging in proprietary/unique charging cables to devices so that i don't lose them, but i wonder if to some degree it might act like this?
i know that generally the current has nowhere to go but not really sure if it could potentially discharge somewhat more than expected from a battery just sitting by itself
diagram below is sorta what i imagine it might look like

Anonymous at Thu, 27 Feb 2025 17:23:15 UTC No. 16601162

>>16601149
holy shit i fucking ESLmaxxed that post
ig that's what i get for writing it piecemeal

Anonymous at Thu, 27 Feb 2025 17:40:38 UTC No. 16601185

>>16601149
>i know that generally the current has nowhere to go
you might want to take a closer look at your diagram.

Anonymous at Thu, 27 Feb 2025 17:56:08 UTC No. 16601197

>>16600211
i get its 0, but how do i do it analytically, should I convert it to x and y or polar coordinates or what

Anonymous at Thu, 27 Feb 2025 18:00:49 UTC No. 16601201

How does the most recent common male ancestor date back to 120,000 years, if many ancestors were neanderthals? If you follow your paternal line, you may eventually end up at a neanderthal ancestor, after which lineages will diverge from homo sapien ancestors

Anonymous at Thu, 27 Feb 2025 18:46:19 UTC No. 16601237

>>16601201
>How does the most recent common male ancestor date back to 120,000 years, if many ancestors were neanderthals?
By definition nobody has a paternal neanderthal ancestor (that we know of) because nobody has neanderthal DNA in their Y chromosomes (that we know of).
> If you follow your paternal line, you may eventually end up at a neanderthal ancestor
So no you won't. There are numerous reasons for this, by memory I believe some of them include things like: male hybrid offspring being nonviable, more likely sterile (Haldane's rule), then-contemporary cultural habits regarding mating (whether men or women relocate upon finding a mate, or both, has a huge impact on genetic trends and tendencies), etc.

Here's a decent article on what we know about the ebbs and flows of various genetic cross-inheritance with the different admixture and out-of-Africa events https://www.science.org/content/article/how-neanderthals-lost-their-y-chromosome

So take all that, add to it extant neanderthals for the more recent interbreeding event already suffering from extreme population collapse and inbreeding, and it simply seems to have disappeared due to natural selection. The lack of genetic diversity in European Neanderthal populations is a big reason for a lot of what was going on genetically, including prevalence of early human DNA in those populations (the as-mentioned human female mtDNA). Since recombined DNA from such sources which have fewer inbreeding-induced deleterious mutations would prove more fit overall. Wash, rinse, repeat, you end up with no neanderthal Y-chromosome and a whole lot of early human DNA in European Neanderthals from early pre-OOA crossbreeding.

In summary, no, you don't have a patrilineal neanderthal ancestor.

Anonymous at Thu, 27 Feb 2025 18:50:45 UTC No. 16601242

>>16601185
i mean obv through the battery wire but the resistor is pretty much just a loose wire right
more accurately the diagram might look something like this maybe?

Anonymous at Thu, 27 Feb 2025 19:04:56 UTC No. 16601252

>>16601242
i still cant really tell what youre trying to draw, or even what youre trying to do, but i dont think it matters.
having a loose wire connected to a pin will not cause it to draw an appreciable amount of current.

Anonymous at Fri, 28 Feb 2025 00:26:13 UTC No. 16601516

>>16600164
>>16601197
https://www.wolframalpha.com/input?i=lim_%28r-%3E%E2%88%9E%29+%28%28r+e%5E%28i+t%29%29+%28r+cos%28t%29%29+%2B+%28r+e%5E%28-i+t%29%29%5E2+-+3+i+%28r+e%5E%28i+t%29%29%29%2F%28%28r+e%5E%28i+t%29%29%5E2+%28r+e%5E%28-i+t%29%29+-+2+abs%28r+e%5E%28i+t%29%29+%28r+e%5E%28i+t%29%29+%2B+3+i%29

Anonymous at Fri, 28 Feb 2025 01:18:49 UTC No. 16601542

>>16601103
probably

Anonymous at Fri, 28 Feb 2025 07:21:13 UTC No. 16601747

>>16584917
Last night my toe suddenly started bleeding as I was in bed, I checked my phone to see if I was dreaming yet the notification is still there now that I am awake the next day. What can cause random bleeding while being still?

Anonymous at Fri, 28 Feb 2025 07:53:57 UTC No. 16601759

What's the consensus on circadian rhythms? I got into an argument saying that CR's can be influenced by genetics to a degree, whereas my friend said no it's pretty set in stone for each human.
I understand that humans wake up with the sun and sleep when it sets, but I'm talking about that genes can influence the offset from these "natural" points.

Let's say I fall asleep at 3am and wake up at 11am, perfectly without any aid or distraction. If I move to a different time zone that would shift that to 12am - 8am, over enough time I'd want to fall asleep at 3am again because the new area's relationship with the sun.

My friend was saying you'd keep the 12am -8am cycle and never fall into your previous cycle.

Anonymous at Fri, 28 Feb 2025 08:44:40 UTC No. 16601774

>>16601759
>I understand that humans wake up with the sun and sleep when it sets
You're already completely wrong at this point and I didn't read the rest of your post. Try googling it first.

Anonymous at Fri, 28 Feb 2025 10:45:53 UTC No. 16601825

if monistic idealism is true then what if blackholes are just what happens when enough consciousness is packed together it collapses, meaning every blackhole is the result of a universe full of units of consciousness evaporating

Anonymous at Fri, 28 Feb 2025 12:09:09 UTC No. 16601848

>>16584917
Is learning maths (from scratch) as a hobby a stupid idea for a loser working min wage job or does it eventually have some real life application?

Where js even the best place to start if you have really touched anything since highschool

Anonymous at Fri, 28 Feb 2025 16:36:09 UTC No. 16602024

>>16601848
It's in the OP. Khan Academy is a good place to start from the absolute beginning.

Anonymous at Fri, 28 Feb 2025 17:34:05 UTC No. 16602050

I'm extremely dumb so bear with me. I was reading about physics and I had some questions.

If energy equals mass, then why can't space equal time? Or let's phrase it differently, what if time is just a property of space, and because space is expanding time moves forward, due to the increased entropy, since space expands there are more possible configurations.

And what if black holes instead of being places of extreme curvature, are just an area where space is contracting. Light isn't trapped in an infinite curvature, it's trapped because light doesn't have space to propagate to. This would tie in with the cosmic horizon, just as light from distant objects can't reach us due to the cosmic horizon, the event horizon of a black hole is because light can't propagate to space that doesn't exist. This would solve the issue of a singularity.

If time is a property of space, and it can contract and expand, this might reconcile the problems between general relativity and quantum mechanics?

Anonymous at Fri, 28 Feb 2025 18:00:32 UTC No. 16602076

Is there some expensive science behind why saltwater pool chlorine generators are so expensive? From what I understand they're just a simple titanium anode inside a pvc housing that converts saltwater into chlorine, water, lye, and hydrogen. Then they need the power supply which isn't terribly powerful, 12v 3-5a is supposed to be good enough and they also have a little timer/control module. What makes that worth $1600+ when you're only at $200 for the electrode, $50 for the outdoor power supply, and the timer can just be wired in with the pool timer itself?

Anonymous at Fri, 28 Feb 2025 23:25:28 UTC No. 16602308

>>16602050
Your post is a bunch of nonsense, but you accidentally hit on something here

>And what if black holes instead of being places of extreme curvature, are just an area where space is contracting. Light isn't trapped in an infinite curvature, it's trapped because light doesn't have space to propagate to
That's actually sort of how it works, but it is more like the event horizon of the black hole is expanding at the speed of light (rather than contracting), and that is why light on the inside can't escape. It can never catch up. The event horizon indeed need not have any appreciable curvature at all. Ironically as the black hole gets more massive the curvature of the event horizon decreases.

Anonymous at Fri, 28 Feb 2025 23:58:46 UTC No. 16602329

>>16602076
I don't know about that product in particular, but price isn't determined solely by the cost of the materials. Off-hand I'd guess it's expensive because pools are expensive, and saltwater pools are unusual. So it's a niche market, likely with little competition, and the consumers can afford hiked up prices.

Anonymous at Sat, 1 Mar 2025 01:16:40 UTC No. 16602382

>>16601848
>Is learning maths (from scratch) as a hobby a stupid idea for a loser working min wage job or does it eventually have some real life application?
It can be very spiritually enlightening and soothing

Anonymous at Sat, 1 Mar 2025 05:22:57 UTC No. 16602502

>>16602382
That's what I was hoping to get out of it at least lol

Anonymous at Sat, 1 Mar 2025 14:17:24 UTC No. 16602716

(x – a)*(x – b)*(x – c) = x^3 – 2143*x + f
a, b, c, and f are integers

find the sum |a| + |b| + |c|

Anonymous at Sat, 1 Mar 2025 14:56:03 UTC No. 16602739

>>16588027
>>16588029
is that Miss Alice?

Anonymous at Sat, 1 Mar 2025 15:03:18 UTC No. 16602745

>>16602716
Consider Vieta's formulas.

Anonymous at Sat, 1 Mar 2025 17:36:45 UTC No. 16602936

can someone explain linear transformations to a smooth brain like me?

in pic, does the A in front of the x imply thats a scalar if not, how am i supposed to interpret this?

Anonymous at Sat, 1 Mar 2025 17:37:57 UTC No. 16602937

>>16602936
i dont know why the image is too small but it should read: T(x) = Ax

and thank you

Anonymous at Sat, 1 Mar 2025 17:45:55 UTC No. 16602943

2+2=?

Anonymous at Sat, 1 Mar 2025 17:53:00 UTC No. 16602947

>>16602943

Anonymous at Sat, 1 Mar 2025 18:45:40 UTC No. 16602983

>>16602936
A is a matrix.
A linear transformation is something that maps a shape onto a different space.
It preserves relative differences, but absolute ones like scale and direction are changed.
So two orthogonal vectors getting transformed remain orthogonal, but may look completely different.
A good way to think about it is using the rotate and stretch/squeeze tools in an image editor.
This also gives you insight as to when a transformation is invertible or not.

Anonymous at Sat, 1 Mar 2025 18:48:57 UTC No. 16602985

>>16602936
There are n numbers in x, so x_1, x_2, ..., x_n. Ax has m numbers, t_1, t_2, ... t_m.
For all t_i, t_i is some linear function of all the x_i's, so for example, 3x_1 - 10x_7 + 4x_9. Thus, T transforms x linearly, as opposed to quadratically or wtv. If you want to output a scalar, you can. If you want 10 numbers, you can.

Anonymous at Sat, 1 Mar 2025 19:37:20 UTC No. 16603040

Why do some microbial colonies grow in a smooth circular shape, while others grow like brain wrinkles? Not finding any good answer online

Anonymous at Sat, 1 Mar 2025 19:55:19 UTC No. 16603054

Dumb question maybe but would a fussion reaction look different to a fission reaction? Uh... If it's about particle speed then I guess it would still be blue... But... Uhhhhh.... Basically, is that the case? Or is there some kind of science thing whereby it's going to be pink or something.

🗑️ Anonymous at Sat, 1 Mar 2025 20:38:31 UTC No. 16603097

Why is the Gerver's sofa composed of those specific curve segments with those lengths? For example why is the XII segment there and why is it so short compared to the others? What determines where the X-segment ands and IX segment starts? How do you even figure this stuff out.

Anonymous at Sat, 1 Mar 2025 20:41:55 UTC No. 16603100

Why is the Gerver's sofa composed of those specific curve segments with those lengths? For example why is the XII segment there and why is it so short compared to the others? What determines the length of the XV segment and its position on the permeter? How do you even figure this stuff out.

Anonymous at Sat, 1 Mar 2025 21:43:43 UTC No. 16603135

Anonymous at Sat, 1 Mar 2025 21:44:45 UTC No. 16603137

>>16603135

Anonymous at Sat, 1 Mar 2025 21:53:00 UTC No. 16603153

>>16603054
Fusion reactions look very different, yes. They can't just sit there in water, they require large devices to contain the plasma electromagnetically, since it's extremely energetic. So it just looks like a lot of plasma in whatever shape the container is using.
The blue glow is from the particles going faster than light in water, which doesn't happen when you have no water.

Anonymous at Sat, 1 Mar 2025 23:11:36 UTC No. 16603233

How difficult would it be to solve this problem? Is it even possible to solve?

Anonymous at Sat, 1 Mar 2025 23:56:24 UTC No. 16603268

>>16603233
1. Intersection only occurs have 3 lines.
2. Every two line configuration can be seen as diameters of two circles
3. The longest possible line is d which only exists if one of the circles is our original circle.
4. Now we have a search space of every two circle pair and which ones they overlap with and which ones they dont.
5. But because we defined the two-line configurations as circles, we can project some integral for circle sizes and relative orientation to each other. Any rotation and size change of a single circle gets us to a line-pair we overlap
6. Further overlaps are reached based on rotation of the whole shape and the angle of the two lines, while non-overlaps are the remainder.
7. Because the circle is a boundary we need some mapping when the elements are rotated from some third position, namely the center of our original circle.
8. There is some division that needs to be done to handle cases of a single line overlap, but its not specifically 1/2 as there are cases of double line overlap.

I might be able to give a formulation up to 6, but 7 requires some other structure I can't think of.

Anonymous at Sun, 2 Mar 2025 00:22:18 UTC No. 16603291

>>16603233
I kind of doubt there's a closed formula for this, but it's easy to find a numerical solution.

Anonymous at Sun, 2 Mar 2025 01:41:46 UTC No. 16603347

>>16603054
Most Cherenkov radiation is UV, which means we can't see it. Look it up for more info

Anonymous at Sun, 2 Mar 2025 02:16:07 UTC No. 16603365

How do you measure the density of water this accurately?

Anonymous at Sun, 2 Mar 2025 02:39:06 UTC No. 16603377

>>16603365
Very carefully
Seriously though just click the number then the article it links to and they explain exactly how

Anonymous at Sun, 2 Mar 2025 03:34:48 UTC No. 16603427

Be honest with me...
aren't Bachelors and Masters just idiot tests to figure out who is smart enough to solve problems in a specific field but also dumb enough to work for free?

Anonymous at Sun, 2 Mar 2025 05:27:33 UTC No. 16603482

>>16603427
yep
true chads do sales

Anonymous at Sun, 2 Mar 2025 07:48:20 UTC No. 16603542

>>16603427
Depends on the field.
A bachelor's is just a test of 'are you compliant enough to wageslave?'
A master's is a joke and badge of shame in my field, but I've heard they're okay in others.
Doctorates are demonstrative of either pure dedication (and thus excellent wageslave material) or actual problem solving ability. You can normally figure out which of the two from an interview or letters.
Meanwhile if you go into fine art or something there's really no reason to ever go to formal schooling since it's just a waste of time and money if you have the passion to learn with your own resources.

Anonymous at Sun, 2 Mar 2025 09:02:28 UTC No. 16603678

I have a mix of different seeds of different shapes and sizes
I want to pour out or scoop out a quantity of this mixture and to have the ratio of seeds in this quantity as close as possible to the ratio of the seeds that I've put in
How do I do it

Anonymous at Sun, 2 Mar 2025 10:53:46 UTC No. 16603787

How do I get better at math? I can solve given equations and understand the concepts, but I can't make even most basic arithmetic equations from given info. For example I can't figure out at all how do I write and calculate how many bags of candies person x has to buy for person y to balance a debt where person y buys 1 bag with 20 candies and he himself takes 4 candies and the rest to person x.
It's harder for me to think that than understanding quadratic equations (which shouldn't be hard for anyone past 8th grade, but I am a retard who barely got out of school).

Anonymous at Sun, 2 Mar 2025 10:58:07 UTC No. 16603790

>>16603787
And I fucked up the problem, person y always gets just 4 from a bag. So how many bags does x need to buy when he just gives 4 each time

Anonymous at Sun, 2 Mar 2025 13:45:41 UTC No. 16603912

>>16603482
>Sales
Even more disgusting
>>16603542
>a badge of shame in my field
Which field would that be?

Anonymous at Sun, 2 Mar 2025 16:48:49 UTC No. 16604118

>>16603678
>How do I do it[?]
1st: mix your mixture
2nd: pour some out

Anonymous at Sun, 2 Mar 2025 16:56:56 UTC No. 16604127

>>16603787
>How do I get better at math?
A: theory, practice, and research
"theory" means read math textbooks
"practice" means work out the exercises or problems in math textbooks
"research" means explore math on your own, or pose and solve your own math problems

Anonymous at Sun, 2 Mar 2025 17:36:57 UTC No. 16604147

>>16604127
So you can't change your natural mind to be more math oriented? You can just learn rules and get experience to use in similar cases, instead of actually understanding and seeing math.
Like I can't understand at all how 2/5 * 6 is the same as 2*6/5, no matter how many times I have seen the proof and gotten it explained. It just doesn't sit in my head.

Anonymous at Sun, 2 Mar 2025 18:57:04 UTC No. 16604258

>>16603912
Physics.
A master's is just someone who quit their PhD program. In industry people probably don't care but up in the ivory tower...

>>16604147
I think you can change it but the question is if you really want to.
Why fight your natural impulses and desires so strongly? I suspect if you liked math you wouldn't struggle so much with it, as you'd do what >>16604127 said for fun. If you don't like math, why are you studying it? If it's just to pass a class for some other degree, fine. Do what you need to and move on. If it's an integral part of the field, I'd seriously reconsider why you're in the field and if you should be. I've personally found out the hard way, and I'm sure plenty of others can attest as well (look at people making career switches later in life), that doing something you hate isn't a good idea, even if the pay or whatever else is good.

Anonymous at Sun, 2 Mar 2025 19:34:01 UTC No. 16604302

>>16604258
>that doing something you hate isn't a good idea
I hate doing everything though, there is nothing in the world I want to do. But I need to do something. I'm over 30, so I don't have much choice just faffing around thinking what I might like. If there was anything I'd really like to do, I would have already found it. There is nothing.
Math is a big part of everything, if you leave it out then the rest is humanities, manual labor or art and I don't want to do those either.
Math isn't fun, but not understanding it isn't fun either.

Anonymous at Sun, 2 Mar 2025 20:05:15 UTC No. 16604332

>>16604302
If you hate everything (I highly doubt this) then kill yourself. Why live in constant pain and suffering?
If you don't, then find something you like.
If you're too stupid/lazy to do so, then pick something easy. Sounds like math ain't it for you.

Anonymous at Sun, 2 Mar 2025 20:08:01 UTC No. 16604337

>>16604332
I'm not suicidal.
>Why live in constant pain and suffering?
Because it's far worse for my family if I die. I don't really care anymore, I just exist day to day.
>Pick something easy
I don't even like playing video games or watching movies, that's the easiest you can get.

Anonymous at Sun, 2 Mar 2025 22:56:32 UTC No. 16604468

>>16602716

🗑️ Anonymous at Sun, 2 Mar 2025 23:52:04 UTC No. 16604493

>>16604468
im not the original guy, but what? None of those are functions of "f"

Anonymous at Sun, 2 Mar 2025 23:56:59 UTC No. 16604495

>>16604468
If f is zero, then the answer is 92.6

Anonymous at Mon, 3 Mar 2025 01:41:11 UTC No. 16604564

>>16603100

Anonymous at Mon, 3 Mar 2025 02:03:13 UTC No. 16604573

I have a HW question that I cannot make any progress on at all. It is a cryptographic question.

[math]
\text{Let } G : \{0, 1\}^n \to \{0, 1\}^{2n} \text{ be a PRG (for every } n\text{), and let } s \in \{0, 1\}^n. \\
\text{Prove that the following construction } is \text{ } NOT \text{ a secure PRG.} \\
\\
G_d(s): \text{ first run } G(s) = x||y \text{ (where } |x| = |y| = n\text{-bits). Then run } G(y) = u||v. \\
\text{Output } x||(y \oplus u)||v. \\
\\
\text{Known fact: if } H : \{0, 1\}^n \to \{0, 1\}^{3n} \text{ is a PRG, then } G(s_L||s_R) = s_L||H(s_R) \text{ is also} \\
\text{a PRG (where } s = s_L||s_R \text{ and } |s_L| = |s_R| \text{ (you can assume } n \text{ is always even).}
[/math]

I'm certain I can perform a reduction to prove, and an adversary can only break this if they can break PRGs? It's using PRG input as a key for the second part, but even then its advantage is only going to be negligible unless you can work out u or y? Unfortunately I don't see how I can use the known fact either, as I'm using the psuedorandom seed instead a truly random seed to append, though that should only be negligably different?

Anonymous at Mon, 3 Mar 2025 02:05:33 UTC No. 16604576

if i can't remember wtf sin or pi is or how to solve a polynomial how's book of proofs going to be? I want to understand proofs for data structures and algorithms i don't really care about math

Anonymous at Mon, 3 Mar 2025 02:06:44 UTC No. 16604578

>>16604573
Should've proofread that last sentence instead of the latex... Should say:

I'm certain I can perform a reduction to prove an adversary can only break this if they can break PRGs?
It's using PRG input as a key for the second part, but even then its advantage is only going to be negligible unless you can work out u or y? Unfortunately I don't see how I can use the known fact either, as I'm using the psuedorandom seed instead of a truly random seed to append, though that should only be negligibly different?

🗑️ Anonymous at Mon, 3 Mar 2025 02:14:56 UTC No. 16604583

test

Anonymous at Mon, 3 Mar 2025 02:42:06 UTC No. 16604606

>>16604495
>If f is zero, then the answer is 92.6
If f = 0, then
a = –sqrt(2143) <> integer,
b = 0, and
c = sqrt(2143) <> integer.
The problem says, that "a, b, c, and f are integers".

The solution says, that a = –49, b = 6, and c = 43.
One of Vieta's formulas says, that f = –a*b*c.
Thus f = –a*b*c = ––49*6*43 = 12642 <> 0.

Anonymous at Mon, 3 Mar 2025 02:49:22 UTC No. 16604613

>>16584917
There is a weapon of some kind which attacks me by playing a sound that shakes my bones and gives me severe depression and other problems. The sound has to be very loud to vibrate my bones, but it is hard to hear somehow. It is really low pitched so maybe it gets too low and ears can't hear it? It causes severe depression and other problems and I need it to stop. How can I soundproof a room completely to keep out this sound?

Anonymous at Mon, 3 Mar 2025 03:04:20 UTC No. 16604620

>>16604573
Looks like I found someone with the same problem, but I don't understand what they're hinting with their answer...

https://crypto.stackexchange.com/questions/103723/let-g-be-a-prg-establish-whether-the-following-prg-candidates-g-g/103731#103731

Anonymous at Mon, 3 Mar 2025 03:05:39 UTC No. 16604623

>>16604613
See an ENT; it's possible your own ears are making the sound. They do this normally but you're not supposed to notice.

Anonymous at Mon, 3 Mar 2025 04:20:53 UTC No. 16604676

>>16602716
a+b+c=0
c=-(a+b)

ring of integers R of Q[sqrt(-3)] is a ufd with Z-basis 1,(1+sqrt(-3))/2. Write s = (1+sqrt(-3))/2

2143 = -(ab+bc+ca) = -(ab-(a+b)^2) = a^2+ab+b^2 = (a+bs)(a+b-bs)
2143 = (43+6s)(49-6s)

norms of 43+6s and 49-6s are both 2143 which is prime so both are irreducible and this is the prime factorization of 2143 in R. b cannot be zero so a+bs and a+b-bs are non-rational integers, which forces b=6,a=43,c=-49 or b=-6,a=49,c=-43. in both cases |a|+|b|+|c| = 98

Anonymous at Mon, 3 Mar 2025 06:37:48 UTC No. 16604736

>>16604676
why can't everything be 0
it's an integer and
[math](0-0)\cdot(0-0)\cdot(0-0)=0\cdot0\cdot0=0=0-0+0=0^3-2143\cdot0+0[\math]

Anonymous at Mon, 3 Mar 2025 06:42:02 UTC No. 16604740

>>16604736
(x-0)(x-0)(x-0) = x^3, not x^3-2143x

Anonymous at Mon, 3 Mar 2025 07:02:37 UTC No. 16604745

>>16604740
...so?
At x=0 it's still true.

Anonymous at Mon, 3 Mar 2025 07:04:07 UTC No. 16604747

>>16604745
>>16604740
I guess I should elaborate; there's no domain given for [math]x\in\{0\}[/math] is just as valid as the reals or integers or whatever else.

Anonymous at Mon, 3 Mar 2025 07:15:13 UTC No. 16604755

>>16604747
>>16602716
>a, b, c, and f are integers

Anonymous at Mon, 3 Mar 2025 08:20:12 UTC No. 16604778

>>16604755
And what's the domain of x?
It's not given, so if it's 0, then 0 works for the others as well.

Anonymous at Mon, 3 Mar 2025 08:33:11 UTC No. 16604784

>>16604778
x has to be in a ring containing the integers or the polynomial makes no sense, and the roots of a polynomial with real coefficients are always complex numbers.

Anonymous at Mon, 3 Mar 2025 09:07:01 UTC No. 16604792

>>16604606
oh, it's a diophantine question

Anonymous at Mon, 3 Mar 2025 09:45:40 UTC No. 16604803

>a japanese mahjong tile set has 136 tiles, consisting of 4 copies of 34 unique tile types (there's a slight caveat here, which is the crux of my question)
>want to know how many unique arrangements a tile wall can have
so far, what I've got (which is borrowed from a stackexchange answer about a similar question about decks of cards) is that there are [math]\frac{136!}{4^{34}}[/math] unique combinations.
thing is, this doesn't account for akadora (which are special tiles that replace one copy of a normal tile which it corresponds to (the five of a given suit); for my purpose there are three in total.) you might think of it like if you shuffled two decks of cards together, but painted one of the ace of spades gold.
is there any way to account for this?

aych at Mon, 3 Mar 2025 10:21:27 UTC No. 16604820

>>16604573
>PRG
so then you're saying,
that 2011 is a PRI = pseudorandom integer?
huh?
you Marine p*nk

Anonymous at Mon, 3 Mar 2025 10:37:57 UTC No. 16604832

>>16604803

Anonymous at Mon, 3 Mar 2025 17:25:52 UTC No. 16605180

>>16604676
>(43+6s)(49-6s) [...] is the prime factorization of 2143 in R
ay?
honestly, this is new to me

there are twelve solutions altogether
but only two distinct solutions
https://www.wolframalpha.com/input?i=%7Ba+%2B+b+%2B+c+%3D+0%2C+a+b+%2B+a+c+%2B+b+c+%3D+-2143%7D

Anonymous at Mon, 3 Mar 2025 17:43:19 UTC No. 16605195

>>16604778
>what's the domain of x?
If domain(x) = {0}, then it's a trivial problem.

Anonymous at Wed, 5 Mar 2025 01:19:14 UTC No. 16607540

Why do I get joint and muscle soreness when I wake up between 1 am and 5 am but not when I wake up around about 6-7 am?
One time I had a very difficult workout session and I woke up at 3 am in a ton of pain but during the day it felt fine

Anonymous at Wed, 5 Mar 2025 02:05:27 UTC No. 16607570

>>16607540
>workout session
you work out?

Anonymous at Wed, 5 Mar 2025 04:45:57 UTC No. 16607679

>>16607540
If you fuck yourself up working out a lot of the time it doesn't actually hurt until the next day.

Anonymous at Wed, 5 Mar 2025 05:22:54 UTC No. 16607699

I'm trying to read euclid to practice logical thinking and I read the problem statement for the proposition and try to solve it on my own, but I haven't actually been able to solve any doing this. When I read how he solves it it makes sense but I feel like I wouldn't be able to think of it.

Should I just spend days on each one trying to figure it out? Am I just retarded? Is doing what I'm doing helpful at all? I never really did math with proofs in school at all

Anonymous at Wed, 5 Mar 2025 16:29:46 UTC No. 16607722

>>16607699
You have to construct the figures, nothing in euclid is a problem to be solved he just wants you to consider what is proposed, are you doing euclid correctly and constructing the figures with a compass

Anonymous at Wed, 5 Mar 2025 16:47:37 UTC No. 16607741

prove that AB=0 iff CD=0 where C,D are the moore penrose inverses of B and C respectively

Anonymous at Wed, 5 Mar 2025 20:22:07 UTC No. 16607981

>>16607741
>C,D are the moore-penrose inverses of B and C
Are you sure you don't mean of A and B?

Anonymous at Wed, 5 Mar 2025 20:24:06 UTC No. 16607983

>>16607981
*of B and A so B+A+=0

Anonymous at Wed, 5 Mar 2025 20:25:53 UTC No. 16607984

>>16607983
...what? Can you write it in full again?

Anonymous at Wed, 5 Mar 2025 20:47:31 UTC No. 16608011

>>16607984
prove that AB=0 iff B+A+=0 where B+,A+ are the moore penrose inverses of B and A

Anonymous at Wed, 5 Mar 2025 21:29:47 UTC No. 16608066

>>16608011
You know that [math]A^+ABB^+=0[/math], and so also [math]\left(A^+ABB^+\right)^t=0[/math]. Since [math]A^+A[/math] and [math]BB^+[/math] are symmetric, [math]BB^+A^+A=0[/math], and since [math]B^+BB^+=B^+[/math] (similarly for [math]A[/math]), you get [math]B^+A^+=0[/math].
The fact that [math](A^+)^+=A[/math] means this also shows the converse.

Anonymous at Thu, 6 Mar 2025 17:02:11 UTC No. 16609019

How do I see what lines the function f(z)=z/z+2i maps the lines Re z=1, Rez=0, Im z=0, I tried using the exponent form put that didn't relaly work out

Anonymous at Thu, 6 Mar 2025 17:51:53 UTC No. 16609168

>>16609019
You know that those kind of functions can map lines only to other lines or circles. So just take the images of three points on the line and you will know which line or circle you get.

Anonymous at Thu, 6 Mar 2025 18:15:10 UTC No. 16609240

>>16584917
Is it bad i dont memorize formulas for calculus, i just reference my notes constantly? I'm old and too tired to memorize this shit

Anonymous at Thu, 6 Mar 2025 18:18:32 UTC No. 16609250

A house in Virginia I stay in, food spoils quickly - homemade bread lasts a week or two at best in a bag.
A house in West Virginia my friend owns, he's had cookies my wife baked him from Christmas, they're still good. Sweet potato bread from a month ago is still good, no signs of decay aside from muted flavor.
Is it because of humidity? Ambient bacteria/fungal levels? Temperature (he keeps it 62° in the house)? I'm at a loss as to why this guy's house is a fucking food cellar.

Anonymous at Thu, 6 Mar 2025 21:11:43 UTC No. 16609555

>>16607722
yes i do the constructions following the steps in the book but i can't figure out the steps on my own

Anonymous at Thu, 6 Mar 2025 21:22:16 UTC No. 16609575

That's it. I'm ending myself tonight. I tried camus. I really did.

Anonymous at Thu, 6 Mar 2025 22:23:42 UTC No. 16609686

>>16609575
based

Anonymous at Thu, 6 Mar 2025 22:32:19 UTC No. 16609696

>>16609686
The boulder coming back down to crush me is going to be based

Anonymous at Thu, 6 Mar 2025 23:49:17 UTC No. 16610348

>>16609575
>>16609696
“Marry, and you will regret it; don’t marry, you will also regret it; marry or don’t marry, you will regret it either way. Laugh at the world’s foolishness, you will regret it; weep over it, you will regret that too; laugh at the world’s foolishness or weep over it, you will regret both. Believe a woman, you will regret it; believe her not, you will also regret it… Hang yourself, you will regret it; do not hang yourself, and you will regret that too; hang yourself or don’t hang yourself, you’ll regret it either way; whether you hang yourself or do not hang yourself, you will regret both. This, gentlemen, is the essence of all philosophy.”
―[math]S\varnothing{}ren\text{ }Kierkegaard [/math]

Anonymous at Fri, 7 Mar 2025 00:24:04 UTC No. 16610699

>>16609555
Don't worry about it, I used to take knowing what a triangle is for granted until I read euclid, keep reading and learning then go back over the propositions and construct them with your new understanding

Anonymous at Fri, 7 Mar 2025 03:43:36 UTC No. 16611179

>>16604803
I got it. for every rank, multiply by [math]\binom{4}{n}[/math] where n is the number of aka in that rank.
so, for a typical aka 3 configuration, its 64, which comes to, after simplifying: [math]\frac{136!}{4^{31}}[/math]

Anonymous at Fri, 7 Mar 2025 04:36:42 UTC No. 16611229

how does he get -b = -(a-) from that?

Anonymous at Fri, 7 Mar 2025 06:18:04 UTC No. 16611276

This is babbys first quantum, forgive me I just watched a few videos and started schizoing, pls don't just call me retarded I already know

How do we know that scenario 2 is not happening rather than scenario 1? How do we know the electrons from the beginning of the experiment are the same electrons detected at the end? Could observing a property of the electrons twice in our dimension change its angle or add a property in a higher dimension that we cant perceive bringing it out of view?

Anonymous at Fri, 7 Mar 2025 06:33:20 UTC No. 16611281

>>16611276
Neither scenario happens since electrons have neither color or hardness (wtf is this???).

Anonymous at Fri, 7 Mar 2025 08:49:28 UTC No. 16611337

>>16611229
b = -a, so plug b inside -b to get -(-a)

Anonymous at Fri, 7 Mar 2025 13:08:07 UTC No. 16611594

omg
look what i drew
how jealous are you?
that's my SQ = stupid question

Anonymous at Fri, 7 Mar 2025 18:11:04 UTC No. 16612023

What is this equal to?

Anonymous at Fri, 7 Mar 2025 19:24:11 UTC No. 16612147

>>16612023
9/11

Anonymous at Fri, 7 Mar 2025 22:15:31 UTC No. 16612343

>>16612147
>9/11
right
you're a good sport

in your image, Canada and Greenland look like a chimpanzee's head or face

Anonymous at Sat, 8 Mar 2025 00:21:22 UTC No. 16612427

Anonymous at Sat, 8 Mar 2025 05:54:30 UTC No. 16612659

Could someone show me the algebra behind these derivations, explicitly? The latter refers to "euler's identities"(plural) which I can't imagine the meaning of apart from the [math] \cos x + {i \sin x} [/math] equation.

Anonymous at Sat, 8 Mar 2025 06:11:23 UTC No. 16612664

>>16612659
Nevermind on the left half—realised it's just a matter of making an equivalent fraction of [math] {m^2}{c^2} [/math] with the denominator of [math] \textbf{p} [/math] and rephrasing [math] c [/math] as the square root of its square. Still lost on the right side.

Anonymous at Sat, 8 Mar 2025 08:24:14 UTC No. 16612724

Anonymous at Sat, 8 Mar 2025 08:47:40 UTC No. 16612729

>>16612664
>the right side

Anonymous at Sat, 8 Mar 2025 15:30:43 UTC No. 16613000

a dodecagram
can be used as
a clock

Anonymous at Sat, 8 Mar 2025 20:17:21 UTC No. 16613211

1/sqrt(3) ~ 15/26
WolframAlpha refused to draw it with the exact value

Anonymous at Sat, 8 Mar 2025 20:26:46 UTC No. 16613216

Can someone explain I find least integer congruent to 10^515 mod 7

Anonymous at Sat, 8 Mar 2025 20:44:13 UTC No. 16613233

>>16613216
>least [positive] integer congruent to 10^515 mod 7

Anonymous at Sat, 8 Mar 2025 21:36:39 UTC No. 16613272

>>16613216
10 is 3 mod 7, so 10^515 = 3^515 mod 7. 3^2 = 9 = 2 mod 7, Times 3 again and you get 6. Times 3 again and you get 4 mod 7. Times 3 again and you get 5 mod 7. Again and you get 1 = 3^0, so it cycles after 6 = 7-1 times (funny huh). So 3^0 = 3^6 = 3^12 and so on. 1, 3, 2, 6, 4, 5. If you started with 0, you stay at 0. Pretty sure you can figure out the rest

Anonymous at Sat, 8 Mar 2025 21:43:58 UTC No. 16613286

>>16613272
Can you explain the way with fermats little theorem

Anonymous at Sat, 8 Mar 2025 23:34:50 UTC No. 16613439

>>16613286
The largest multiple of 7 that doesn't exceed 515 is [math]73 \times 7 = 511[/math]
so [math]10^515 = 10^4 \times 10^511 = 10^4 \times (10^73)^7[/math]
Since 7 is prime, FLT tells us that, working mod 7, [math](10^73)^7 \equiv 10^73[/math], so we can reduce to [math]10^4 \times 10^73[/math]
But that's [math]10^77=(10^11)^7[/math], and we can invoke FLT again to reduce that to [math]10^11[/math]
and so on.
Basically, you just keep breaking off and recombining terms to get things of the form [math]a^p[/math], where p is the prime you're working modulo

Anonymous at Sat, 8 Mar 2025 23:36:33 UTC No. 16613442

>>16613439
I'm incompetent and it's been too long since I've used TeX, apparently.
Correct things to [math]10^{515}[/math], [math]10^{511}[/math], [math]10^{73}[/math], [math]10^{77}[/math], and [math]10^{11}[/math] where applicable.

Anonymous at Sun, 9 Mar 2025 00:10:09 UTC No. 16613478

In the following list, {u, v} means that the numerator of the ratio (pi^u)/zeta(u) is divisible by v and by every odd prime number which is less than v.

{2, 3}
{4, 5}
{6, 7}
{8, 7}
{10, 11}
{12, 13}
{14, 13}
{16, 17}
{18, 19}
{20, 19}
{22, 23}
{24, 23}
{26, 23}
{28, 29}
{30, 31}
{32, 31}
{34, 31}
{36, 37}
{38, 37}
{40, 41}
{42, 43}
{44, 43}
{46, 47}
{48, 47}
{50, 47}
{52, 53}
{54, 53}
{56, 53}
{58, 59}

Why is this?
I don't think, that anyone in /sci/ knows.

Anonymous at Sun, 9 Mar 2025 05:58:32 UTC No. 16613710

>>16613286
x^0 = x^6 = x^12 mod 7
x^1 = x^7 = ... mod 7
X^2 = x^8 = ... mod 7
Use the other guys explanation, and notice that he's using the second rule (FLT). It's all the same

Anonymous at Sun, 9 Mar 2025 06:04:54 UTC No. 16613711

>>16613478
>I don't think, that anyone in /sci/ knows.
then why ask, lol. Sounds useless

plpl at Sun, 9 Mar 2025 07:51:00 UTC No. 16613763

now solve this

Anonymous at Sun, 9 Mar 2025 08:12:18 UTC No. 16613773

>>16613763
I score that a 4

Anonymous at Sun, 9 Mar 2025 10:16:16 UTC No. 16613832

>>16613478
For example, the ratio (pi^28)/zeta(28) is a rational number.
And its numerator is divisible by every odd prime number which is less than or equal to 29.

Anonymous at Sun, 9 Mar 2025 10:31:07 UTC No. 16613837

>>16613773
>4
right
>yep, that[']s a troll
"it takes one to know one"
and look at those dirty fingernails

Anonymous at Sun, 9 Mar 2025 10:53:16 UTC No. 16613850

>>16613478
Dear Anon, there is a dedicated math thread on /sci/. I urge you to post your revelations there.

Anonymous at Sun, 9 Mar 2025 15:44:37 UTC No. 16613992

>>16613850
>there is a dedicated math thread
That thread mentions Zeta(2) and Zeta(–1), but it's mainly about "sleight of hand".
Such threads are popular on /sci/.
And what I posted ITT is different.

Furthermore, that thread is about to be archived.
It's like a sinking ship.

Anonymous at Sun, 9 Mar 2025 18:23:50 UTC No. 16614098

>>16613478
The ratio (pi^16)/zeta(16) is a rational number, and its numerator is divisible by every odd prime number which is less than or equal to 17.

lowercasesage !!4DQphUM8gee at Sun, 9 Mar 2025 18:42:48 UTC No. 16614116

>>16613478
>Why is this?
It might be associated with the explicit formula for Zeta(2n), n>1