Partial Differential Equations!

[UnhealthyTruthseeker]

I'm going to High School next year, so I'll be looking to you as my mentor

If you're going to college for math and/or physics (seems a very high probability that this is true), there's a very high chance that any differential equations class you take will use Elementary Differential Equations and Boundary Value Problems, although it might not use the same version I used.

[Fartsniffage]

I used to be very good at maths.

All the words in this thread ring bells but when I focus on them their meanings just slide out of reach.

[UnhealthyTruthseeker]

I used to be very good at maths.

All the words in this thread ring bells but when I focus on them their meanings just slide out of reach.

This seems to be a pattern with people on here. Since I'm going along the physicist route, I think I won't have to face this "use it or lose it" problem.

[New Kereptica]

I used to be very good at maths.

All the words in this thread ring bells but when I focus on them their meanings just slide out of reach.

This seems to be a pattern with people on here. Since I'm going along the physicist route, I think I won't have to face this "use it or lose it" problem.

Lucky bastard.

[Fartsniffage]

This seems to be a pattern with people on here. Since I'm going along the physicist route, I think I won't have to face this "use it or lose it" problem.

I went along an engineering route but only 1 year at college. The A level pure was more indepth than that year to be honest.

You think a degreee in Politics would have helped me more around here than it has though...

[UnhealthyTruthseeker]

Lucky bastard.

Grad school and then postdoc isn't exactly all fun. There's a reason why there aren't that many professors.

[New Kereptica]

Lucky bastard.

Grad school and then postdoc isn't exactly all fun. There's a reason why there aren't that many professors.

Grad school was horrible, but in retrospect, I'd rather go through that all and worse than forget what I've forgotten.

[Tunizcha]

I used to be very good at maths.

All the words in this thread ring bells but when I focus on them their meanings just slide out of reach.

This seems to be a pattern with people on here. Since I'm going along the physicist route, I think I won't have to face this "use it or lose it" problem.

I hope to see you posing with the likes of Michio Kaku, Edward Witton, and Stephen Hawking (before he dies, of course) in the near future

[UnhealthyTruthseeker]

I hope to see you posing with the likes of Michio Kaku, Edward Witton, and Stephen Hawking (before he dies, of course) in the near future

My portrait.

[New Kereptica]

I hope to see you posing with the likes of Michio Kaku, Edward Witton, and Stephen Hawking (before he dies, of course) in the near future

My portrait.

You look familiar.

[UnhealthyTruthseeker]

What about the Dirac equation, which predicts the existence of antimatter?

[UnhealthyTruthseeker]

http://en.wikipedia.org/wiki/Quantum_electrodynamics

There's some extreme pain on that page.

[Blouman Empire]

What is there to discuss -_-

Would you rather discuss abortion for the 3.34 x 10²⁸th time?

Yes, this is NSG after all.

But how about we shake it up a bit and go for evloution real ot not? or Gays, should they be allowed to marry?

[Tunizcha]

http://en.wikipedia.org/wiki/Quantum_electrodynamics

There's some extreme pain on that page.

*grumble* Damn you.

[UnhealthyTruthseeker]

Yes, this is NSG after all.

But how about we shake it up a bit and go for evloution real ot not? or Gays, should they be allowed to marry?

Hey, how about "Is there a God?" Or even better "Did Jesus ever exist?" Hell, why don't we combine them all into a single thread and mix in abortion, the death penalty, health care, and laissez faire capitalism as well? The NSG thread to end all NSG threads.

[Tunizcha]

Yes, this is NSG after all.

But how about we shake it up a bit and go for evloution real ot not? or Gays, should they be allowed to marry?

Hey, how about "Is there a God?" Or even better "Did Jesus ever exist?" Hell, why don't we combine them all into a single thread and mix in abortion, the death penalty, health care, and laissez faire capitalism as well? The NSG thread to end all NSG threads.

The mods said that they don't want a permanent mega-thread that would keep being rekindled.

[Christmahanikwanzikah]

Here's another set of nice equations:

Let there be light:





The equation for B_x(x), B_y(y), and B_z(z) is always separable and thus solvable. (basically)

The equation for E_x(x), E_y(y), and E_z(z) is like the Schrodinger equation in that it is separable as long as you can find the right coordinate system.

The equations for things like E(t) and B_x(y,z) are usually not too bad, and are, again, separable if you pick the right set of coordinates.

Electrical physics, how I have missed (not really) thee...

[Deus Malum]

Let's discuss Partial Differential Equations!

Laplace's equation is nice to work with because it is homogeneous and linear and hence always separable. It's solutions are many, but they are always of a polynomial or exponential nature. Physically, Laplace's equation usually implies some superposition of wave-like behavior in a scalar field.

The equation for a solenoidal vector field (that the vector field has zero divergence) is also very easy to solve and is always separable, but it also doesn't reveal the entire picture. It cannot tell you how the x component of the vector field depends on an additive term containing the y and z variables, for example. In order to figure out the full behavior of the vector field, you must know its curl field as well.

EDIT: I should correct myself. The solutions to Laplace's equation are always of a polynomial or exponential nature for coordinates in a holonomic basis.

We dove right into the heat equation in Intro to PDE. It's curl-into-a-ball worthy painful math. Even in one dimension, formulating the general solution for the heat equation for an insulated pipe with variable cross sectional area is an enormous pain in the ass.



Where q is heat sourcing.

[The Archregimancy]

Lucky bastard.

Grad school and then postdoc isn't exactly all fun. There's a reason why there aren't that many professors.

There's at least one on NSG!

Me.

Unfortunately, my PhD is in archaeology, and I'm based in a department of archaeology and ancient history - so I don't have the foggiest notion what anyone here is going on about.

Now, if you needed someone to teach you how to seriate pottery sequences, or how to interpret the shifting ideological implications of post-medieval pottery decoration, I might be able to help, but partial differential equations? I think I'll pass.

[Deus Malum]

Lucky bastard.

Grad school and then postdoc isn't exactly all fun. There's a reason why there aren't that many professors.

There's at least one on NSG!

Me.

Unfortunately, my PhD is in archaeology, and I'm based in a department of archaeology and ancient history - so I don't have the foggiest notion what anyone here is going on about.

Now, if you needed someone to teach you how to seriate pottery sequences, or how to interpret the shifting ideological implications of post-medieval pottery decoration, I might be able to help, but partial differential equations? I think I'll pass.

We've actually got a couple of Ph. D.s, including one in physics, though I don't believe he works as a prof.
Plus a grad student in physics.

...and now that I think about it, isn't there another archaeologist on this forum?

[UnhealthyTruthseeker]

We dove right into the heat equation in Intro to PDE. It's curl-into-a-ball worthy painful math. Even in one dimension, formulating the general solution for the heat equation for an insulated pipe with variable cross sectional area is an enormous pain in the ass.



Where q is heat sourcing.

I could perceive possible pain if q is a function of more than one of the space variables. If it isn't, then this should separate relatively easily. The real problem would happen if q depends on both space AND time. That would really fuck shit up, because you might have to find some alternate coordinates for space and time.

[UnhealthyTruthseeker]

I could perceive possible pain if q is a function of more than one of the space variables. If it isn't, then this should separate relatively easily. The real problem would happen if q depends on both space AND time. That would really fuck shit up, because you might have to find some alternate coordinates for space and time.

Also, I guess it could be kinda bad if your thermal diffusivity is not a constant but varies in space and/or time.

[Taeshan]

Says to self, I HAT MATH, then replies, Then why are you in Honors Algebra 2 in 10th Grade?

[EvilDarkMagicians]

Code: Select all

"Find x > 3 such that

ln(x) < x^(0.1)"

Bet no one on here can figure this one out

[UnhealthyTruthseeker]

Says to self, I HAT MATH, then replies, Then why are you in Honors Algebra 2 in 10th Grade?

I try not to HAT anything, mostly because I don't know how to HAT something.

Am I an asshole?