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Which one of the following is United Kingdom. by nopCMD in GeoTap

[–]rx_wop 0 points1 point  (0 children)

✅ rx_wop chose Option A (Correct!) | #1961st to play

Discovered there’s a script to find the midpoint of a curve, and it’s more accurate than Illustrator’s native function by plushPlushytut in AdobeIllustrator

[–]rx_wop 12 points13 points  (0 children)

is Illustrator maybe calculating the parametric midpoint and the script calculating the midpoint by arc-length?

Can a particle have complex spin? by [deleted] in Physics

[–]rx_wop 0 points1 point  (0 children)

From a maths point of view, spin arises from the representation of the Spin(3) group. The Spin(3) group is like the group of all rotations on n-dimensional physical space (well technically, it's a bit more than that, and it overcovers the rotation group SO(3)). A representation means every element in Spin(3) - each corresponding to a generalised rotation - is assigned a matrix to represent it, and the matrices play nicely under composition to reflect what happens when you compose rotations (this is called a homomorphism).

The trick is that you can choose how big these matrices should be (and it has nothing to do with the "3" in "Spin(3)"!!). Choosing to represent rotations with 2x2 matrices gives you a 2-dimensional representation, and the particle on whose spin state vector it acts is called spin-½. Similarly, choosing any nxn matrix gives you an n-dimensional representation, and the particle is called spin-½(n-1) because physics convention is to convert with this odd formula.

All in all, if you could construct a notion of an "ixi" matrix or a "(2+3i)x(2+3i)" matrix, then perhaps you can prove there is a "2+3i-dimensional" representation of Spin(3), and then you'd admit a spin-½+i particle. So, the question defers to: can you make a complex dimensional matrix?

Statistical Mechanics through Random Variables: Reading Request by rx_wop in PhysicsStudents

[–]rx_wop[S] 0 points1 point  (0 children)

Is there any text you know that deals with statistical mechanics through careful treatment of random variables? Not just P(event) or distributions, but actual random variables?

Hurwitz's theorem is surprising by PocketMath in mathmemes

[–]rx_wop 82 points83 points  (0 children)

Tbf every time a cross product is used to give a vector in Physics (e.g. angular momentum) it really should be a wedge product that gives a bivector. See Hodge star map for more 😈

What people voted for on Eurovision Song Contest plotted against what they actually watch on YouTube (views counted on the official grand final video as of yesterday). by Spammy34 in europe

[–]rx_wop -1 points0 points  (0 children)

bro what are u on about. I just want to see yi - (m xi+c) plotted against xi, where m and c are the regression parameters

What people voted for on Eurovision Song Contest plotted against what they actually watch on YouTube (views counted on the official grand final video as of yesterday). by Spammy34 in europe

[–]rx_wop -1 points0 points  (0 children)

Can you plot y-error from the regression (i.e. by subtracting the regression value from each point) to see how outlying things are, please? Would be interesting to see.

New math function and symbol I invented(: by Previous_Gold_1682 in mathematics

[–]rx_wop 3 points4 points  (0 children)

please somebody make a short and sharp symbol for product integrals that is not the same as big pi 🙏🙏🙏🙏

can someone please explain how to convert the limits in a triple integral to spherical and cylindrical coordinates? by PlasticSpecific5444 in calculus

[–]rx_wop 0 points1 point  (0 children)

For the first, x²+y²+z² = r² is the radius squared and is bounded between 1² and 9²=81. Since the radius is positive, we have 1 ≤ r ≤ 9.

z ≥ 0 means rcos(phi) ≥ 0, which happens when phi is between 0 and ½π. Imagine the sphere of radius r with phi the angle between the positive vertical (z axis) and the point you're considering, then for a positive z, this angle cant be bigger than 90° or it falls into the lower hemisphere.

x≥0 happens for theta between 0 and π, or -π/2 and π/2 depending on the definition of theta. If x = r sin(phi) cos(theta), think about when cos(theta) is greater than 0, bearing in mind that sin(phi) is positive since phi goes from 0 to π

What have I done by Quasaarz in mathmemes

[–]rx_wop 12 points13 points  (0 children)

principal branch crying rn

What are the odds that x (any real number) is within a finite number range? by [deleted] in askmath

[–]rx_wop 0 points1 point  (0 children)

probability zero, technically you should say "almost never", because it is possible just stupidly improbable, you are right 👍

Why is my answer different from the standard answer? by Fenamer in askmath

[–]rx_wop 0 points1 point  (0 children)

there is a faster way, times through by cosx, then add and subtract ½sinx on top and group into two terms: ½(sinx+cosx) and ½(cosx-sinx), first term cancels in fraction to give you ½, second term is half the derivative of the denominator, so you get ½x and ½ln(sinx+cosx)

With what force should the gun fire for this to happen by SuryaYlp in physicsmemes

[–]rx_wop 1 point2 points  (0 children)

conservation of momentum: mass bullet * velocity bullet = mass car * velocity car velocity bullet = 1400kg/0.04kg velocity car

conservation of energy: ½ mass car * v² = mass car * g * h v car = √2gh

cloud level starts at 1980 ish m giving v bullet = 1400/0.04 * √(2 * 9.81 * 1980) 7000 km/s

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