Have You Seen the Hilarious Geeky Physics Comic from xkcd.com?

[SF]

I stumbled over http://xkcd.com/c182.html" a couple of days ago and I found it so funny that I literally LOL-ed.
My friends thought I was just being weird.

Don't you think it's hilarious?

 

[Beeza]

That is excellent.

 

[JasonRox]

I laughed out loud too.

It's good.

 

[chroot]

So Feynman liked the ugly ones, too, did he?

- Warren

 

[JasonRox]

So Feynman liked the ugly ones, too, did he?

- Warren

Aren't there two ways to this?

Feynman walks away with the girls, which takes them away from the guys.

And...

Feynman is the reason for there obsession on equilibrium, hence they miss out on the girls.

 

[selfAdjoint]

It's great! And if you know about Feynman, after his first wife, the love of his life, died, he turned into a ruthless bar-hopping chick exploiter. I think the comic works off that rep.

 

[Ivan Seeking]

It's great! And if you know about Feynman, after his first wife, the love of his life, died, he turned into a ruthless bar-hopping chick exploiter. I think the comic works off that rep.

I thought that later he quit drinking and started playing the bongos.

 

[turbo]

Before you can cull them, you've got to learn to cut them.

 

[Moonbear]

It's great! And if you know about Feynman, after his first wife, the love of his life, died, he turned into a ruthless bar-hopping chick exploiter. I think the comic works off that rep.

Okay, now it's making sense. I didn't vote because I didn't know if I didn't get it or if it was just lame.

 

[mattmns]

I know who Feynman is, and I think I have heard of Nash, but to be honest I don't get it

 

[moose]

Ok, I hate explaining jokes, but here goes.

So the guy talks with Nash about applying Nash's theory to get the best result. They are getting technical about everything.

Feynman, on the other hand, has always had a straight-forward approach at life. Combine that with his past with women and about just asking, etc.

However, maybe I'm missing something. Maybe Feynman had some theory which has to do with this or something?

 

[neutrino]

Anything XKCD is hilarious, so much so that I have it open every morning when a new comic is up.

 

[Math Is Hard]

*leaves with Feynman*

 

[Knavish]

Favorites

http://www.xkcd.com/c32.html
http://www.xkcd.com/c42.html
http://www.xkcd.com/c45.html
http://www.xkcd.com/c123.html
http://www.xkcd.com/c135.html
http://www.xkcd.com/c162.html

 

[JasonRox]

*leaves with Feynman*

I'm with you on that one. :!)

 

[BobG]

http://www.xkcd.com/c32.html
http://www.xkcd.com/c42.html
http://www.xkcd.com/c45.html
http://www.xkcd.com/c123.html
http://www.xkcd.com/c135.html
http://www.xkcd.com/c162.html

The last one should be a Hallmark card.

In the second to last one, how the heck are we supposed to remember raptors only run at 10 m/s when we were already told they run at 25 m/s (except when injured)? No wonder the students are whining?

 

[Kalimaa23]

Brilliant!

 

[twisting_edge]

In the second to last one, how the heck are we supposed to remember raptors only run at 10 m/s when we were already told they run at 25 m/s (except when injured)? No wonder the students are whining?

Actually, that second one is a pretty interesting problem. You have all the information necessary to solve it, although the solution might be a little more involved than you think.

For example, your best strategy may not be a straight line: the raptors will supposedly run straight at you. Running along a curved path might buy you a few extra milliseconds since the raptors will have to run slightly farther as they adjust their course.

Isn't this precisely the sort of thing they resurrected the Hamiltonian for? Solving weird problems where you know the end conditions but not the path between them? I am sure a Hamiltonian analogue exists for the wounded raptor problem.

 

[selfAdjoint]

I thought that later he quit drinking and started playing the bongos.

Yes he did, and gradually pulled himself out of his bitterness and eventually found happiness with his third wife. His second wife was a disaster, and she divorced him.

But during the "great period" when QED was being formed, he was a chaser.

 

[twisting_edge]

Actually, that second one is a pretty interesting problem. You have all the information necessary to solve it, although the solution might be a little more involved than you think.

I can't sleep, and my mind has chosen this one to pick on.

It is a somewhat interesting problem, but not very in the specific case. A more general solution is probably insoluable. But some generalities might be fun to review. Either that, or my brain is seriously misfiring at this late hour (almost certainly the latter).

In the case of identical raptor speed, sufficently low relative victim speed, the victim cannot cross the border of the triangle. His best move is to remain still. That much is obvious. We'll also assume instantly accelerating raptors smart enough to aim where the victim will be (as opposed to where he is) at this time, although it is not relevant in this case.

With one wounded raptor, his best move is to run (possibly not at full speed) toward the wounded raptor. By symmetry, this is also a straight line.

With equal raptor speeds and less disparate predator/prey speeds, the victim can cross the line delimiting the initial raptor triangle. His best move is full speed towards a boundary, and straight on from there. Once again, line remains straight by symmetry.

With one wounded raptor and less disparate speeds, I am fairly sure his best path becomes elliptical some critical distance after crossing the boundary. It may be a circular segment. But I think the condition of fully anticipatory raptors is starting to break down in that analysis.

I am fairly sure making the raptors run towards his current (as opposed to future) position yields an elliptical (or other conic section) post-critical path.

Once you allow for finite raptor acceleration, it's starting to look a lot like the three body problem, only not quite so bad. I suspect there's still a discontinuity in the second derivative of the victim path at a critical point outside the triangle.

Anyone care to run with this line of speculation from here (and away from the raptors)? Triple points will be taken down in evidence against you should you actually put pencil to paper and start to work out the math.

P.S.: The raptors may have to slow at times depending on the curvature of their respective paths at that point.

 

[Gokul43201]

http://www.xkcd.com/c184.html

Brilliant!

 

[Gelsamel Epsilon]

I love xkcd so much :D

 

[twisting_edge]

There's a general rule of raptor interceptions after that last post. If the victim speed is less than the wounded raptor speed, the terminal point always involves the simultaneous interception by two raptors. This is a less interesting conclusion.

But just what is the path of an omniscient raptor chasing omniscient prey? The problem is to solve for maximum victim survival time, so we can skip the motivational issues associated with fatalism.

Assume a solution. Most likely, this solution will involve dodging around the wounded raptor. The raptor heads straight for the intersection. But if the raptor is going to head straight for the intersection, the victim can skip curving around the range of possible raptor positions and head straight for the intersection himself. But the new victim path would travel back in time to the initial condition, and the omniscient raptor would adjust its path to intercept the victim earlier. The omniscient victim then adjusts his response to the new raptor path, etc.

It's a race condition. The best model would be an expanding circular locii of possible raptor positions, with the victim path restricted to those areas outside the locii. It's not a perfect model, but perfect omniscience is tough to model (uless you have it yourself). For constant raptor speed, it's an odd sort of "constant linear velocity" spiral, where the radius from the center is strictly proportional to the to the total path length along the spiral to each point.

The omniscient victim chased by the omniscient raptor wants to run to run along a tangent to the wounded raptor's spiral potential presence locus, and then follow that spiral, dodging just outside the wounded raptor's possible positions, until the unwounded raptor nails him more or less from behind.

If the wounded raptor speed is greater than the victim speed, the victim can never leave the spiral. If the wounded raptor speed is less than the victim speed, there exist conditions where he may be able to leave the spiral and run directly fromt he unwounded raptor. It is only in those cases you have a single raptor kill.

(I decided to blow the morning off work, in case anyone's wondering.)

 

[Chi Meson]

Yes he did, and gradually pulled himself out of his bitterness and eventually found happiness with his third wife. His second wife was a disaster, and she divorced him.

But during the "great period" when QED was being formed, he was a chaser.

I did not know that!

I knew he had a first wife who died of TB, and I knew he had a third wife...

But this is the first time I ever heard of a second wife!

 

[TuviaDaCat]

I stumbled over http://xkcd.com/c182.html" a couple of days ago and I found it so funny that I literally LOL-ed.
My friends thought I was just being weird.

Don't you think it's hilarious?

holy crap, this very moment i came to pf to post this link, and there i see this post... heh, though I am sure that both you and i seen the link with the e^pi*i.

 

[TuviaDaCat]

I know who Feynman is, and I think I have heard of Nash, but to be honest I don't get it

it would have been easier to understand the joke if you saw the movie "beutiful mind"