/sci/ - Science & Math

Does Becky have a thing for Dave?

what is the kernel of the diffusion equation?

A number is an awesome number if each of its digits are strictly decreasing. e.g. 865310 is awesome. How many awesome numbers are there?

>>2916659
Ok. Why is the sky blue? Go!

What's the formula to find the volume of a cone

Do you want to touch wieners?

What is 110% of 90% of 10?

Is any ethical system empirically superior, assuming there is no higher dictatorial power?

Why can't I see Jesus? Is he made of neutrinos or dark matter?

What is the 35^9th decimal place of pi?

>>2916687
The better question is does a higher dictatorial power change the question at all?

>Either it's good because it's innately good, and thus the higher power is irrelevant, or it's innately good because it's the preference of the higher power who is free to decide tomorrow that rape is good.

Describe Salmonella's ability to undergo antigenic phase variation.

>>2916659
Is there an all powerful magic man in the sky? does this magic man cares about you? can you "pray" to this magic man for magic wishes?

Any 1st grader should know the answer to these.

OP got stoned and forgot about the thread he made

Why is gravity?

>>2916671
No. But she does for Olivia.
>>2916674
No idea.
>>2916675
(pi times r^2h)/3 I believe.
>>2916676
No, but I hear vaginas make a mournful sound when touched.
>>2916677
Because the gases in our atmosphere refract all but the blue colored light wavelengths, so it looks blue to us. I think this is also why deep water looks black or muddy, but clean shallow waters are blue.
>>2916680
Tricky since you can skip digits. I don't know, but maybe 9! is the answer?
>>2916683
9.9
>>2916687
Probably not, but possibly. If I had my bet, I'd say the more mathematical a system is, the more empirically valid it has the potential to be, so utilitiarian systems probably have a better shot than others.

>>2916692

Jesus took Improved Tactical Cloak at power Level 4, so you need to wait for him to come out and try to survive his headshot. Try rolling as a Sentinel; I hear Tech Armor can do the trick against Jews at high levels.
>>2916695
No idea, so I'm guessing 4.
>>2916702
nope
>>2916722
just drunk, actually, but same thing almost
>>2916727
Actually, nobody knows this for sure. Supposedly it's one of the four fundamental forces, but unlike the others we can't really describe where it's coming from beyond vague allusions to "dark matter" and "dark energy", which is scientific shorthand for "no fucking idea." Lots of things we know HOW they work without knowing WHY they work, and this is one.

>>2916728

the answer of >>2916683 is 9.1 kid xD
1.10(0.9(10))

What's the physical interpretation of an index of refraction less than one?

Why doesn't this violate the laws of physics?

>>2916728


the "kernel" of the diffusion equation, like all other PDEs, is the Greens Function.


the diffusion equation is used as a special example because its kernel is typically used a solution (as well as a kernel)


the kernel works like this:


its like the fourier transform or laplace transform for that specific problem.
basically, it lets you "expand" any inhomogenous/source term in a "basis" of the kernel.
you do this by assuming that the PDE is solved for a spectrum of "unit impulse distributions" (dirac delta functions).


all of this is done because the dirac delta has useful properties as a distribution (with respect to its spectral/fourier series properties).
coincidentally, in a PHYSICAL way: the Diffusion equation, in its most simple form, has boundary conditions that are the same as the form of the Green's function problem.
you assume, in a simple diffusion problem, that the initial distribution of concentration/density/whatever is approximately reprsented by a unit impulse.


at time zero, you add Salt, or a drug molecule, or heat to a system...

that Phi(T=0) distribution looks like a dirac delta.
the kernel of the diffusion equation is therefore "equivalent" to its solution (for a homogeneous problem).
the solution is the Gaussian (e^(-cx^2))with respect to a change of variables and a prefactor.

>>2916776


kerr effect? or am i getting that mixed up...


I think they use this to fix chirping with a GVD filter.

>>2916748

No. 90% of 10 is 9, and 110% of 9 is 9.9. He asked what is 110% of 90% of 10, and your parentheticals don't describe that phrase correctly.

>>2916776
So far as I know, you can't actually have an index of refraction less than one without violating physics. You can have negative indices of refraction using weird metamaterial shit that I have no clue about, but since 1.00 represents the speed of light in a pressure-zero vacuum, I don't know that you can get closer to zero than that on the positive side of numbers.

>>2916748
1.10 x (0.9 * 10) = 9.9

Ask google, idiot

>>2916808

how is the solution to what you wrote different from what he wrote, except that his is easier to read since you added so many words and steps and he used a nice equation?

pascal?

sec(x)=1/(csc(x)+cot(x))

can you verify this indentity

>>2916808
Took the time to google it, couldn't do it mentally?

>>2916837

Uh, because my answer is correct mathematically, and his is not? In fact, I don't know where he got 9.1 from in the first place. Whether you do 1.1*(.9*10) or (1.1*.9)*10, both come out to 9.9.

So the difference is that his multiplication is bad.

But hey, his answer was nice and short, and mine had like words and stuff. Derp.

>>2916849

Pretty sure that's right. I remember secant, cosecant and cotangent being triangulated somewhat like that.

>>2916857

Oh, I get it. You're a troll, doing troll math to try to derail. Nice.

>>2916849
this. fucking this op

>>2916870
trolololololol

>>2916863
>your parentheticals don't describe that phrase correctly.
this is the part of what you said that was wrong
he was correct in his parentheticals, just not his final computation

>>2916659
What is the Capital of Poland?

>>2916888

Actually the parentheticals were technically incorrect for not simplifying too, as the parentheses around 10 are unnecessary.

Come on /sci/, I know you have more 7th-grade crap to ask.

>>2916905
accidental pseudo-sage

>>2916905
Shit. It's either Krakow or Warsaw.

Actually, I think it was first one, then the other.

>>2916922

Wait, I know! It is Warsaw, because it was Krakow in that Calvin and Hobbes comic where he was in history class pretending to shoot Susie and got the answer right.

Kra-Kow! Kra-Kow!

>>2916728
the atmosphere ABSORBS all spectrum of light but blue, not refracts it.

>>2916934

...damn, I at least get partial credit for having the right idea.

>>2916907

but the way they are... they describe the problem perfectly fine, the solution offered might not be as simplified as it could be, but that doesn't make it wrong, even though I am pretty sure parenthesis are never needed in a pure multiplication problem

>>2916922
You lucked out this time OP! What nation initially declared war in WWI and what nation did it declare war against?

>>2916728
>refract
RAINBOWS EVERYWHERE

>>2916959

Austria because someone important got shot. I think it was... Serbia? Then Germany declared war on someone because they were allies with someone, and then things kinda went to hell.

>>2917013
lol it was the Austo-Hungarian empire on Serbia because Franz Ferdinand got shot. Then Russia declared war on AH empire because of their alliance with Serbia, and Germany went ahead and joined the party and blah blah blah.

You got it somewhat right. You might have passed with a 60-65%

Ahahahah alright... I've got one for you that I knew when I was your age -
What was the name of Archduke Ferdinand's assassin?

>>2917039

All I remember for sure is that there was a list of demands, and the only one Serbia didn't wanna go along with was investigating the dude's murder, and apparently that was enough to start a goddamned world war over. I always thought the Austria-Hungary people were kinda overreacting dicks for that, but whatever.

>>2917050

Gavrilo Princip, I know that one. Also, I'm not actually a 7th grader, I was just using that as a guidepost for the questions. Because I know if I mention my actual level of education, people will start throwing quantum physics at me and I'm not a goddamned engineer.

>>2917068
Fair enough.

Which important Russian Communist was exiled by the Bolsheviks and later murdered by the NKVD in Mexico?

>>2917097
With an ice pick no less.

>>2917097

Leon Trotsky, and I remember that it was with a fucking ice pick. The dude hit him in the skull with an ice pick, and Trotsky's bodyguards were going to kill him until Trotsky said to leave him alive for questioning. He took a full day to die from the wound or some shit, I remember thinking he was basically a boss at that point.

>>2917097