h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

The headache you get from proving the Fundamental Theorem of Calculus one time too many.

Ever get your epsilons in a twist?

epsilon, epsilon.. can't remember what that is...

That's the quantity by which the function at x plus delta differs from the function at x.

Oh. Didn't know that. All I could think of was epsilon (subscript) 0, and I think that's a the permability of free space or something.

Or permittivity ... I can never remember which. It all gets glued into something called the fine structure constant in the end. I think permittivity and permeability combine together in an interesting way to be the speed of light, too ... god old Maxwell ....

That should be 'good', of course.

I just remember it from the constant: 1/(4 pi epsilon 0)

There are not enough symbols on this keyboard!!

I think that is permittivity ... truth to tell, though, I can't remember.

Hmm.

http://www.google.co.uk/search?q=maxwell+equations&ie=UTF-8&oe=UTF-8&hl=en&meta=

too long ago. About 2 months

True, true ...

... I like the Maxwell equations, though. It turns out they aren't Galilean invariant (i.e. if you use conventional Galilei-Newton transformations to change from looking at them from, say, the earth to a spaceship doing 11 km/s, they don't work any more -- you need Lorenz transformation, i.e. relativity).

Yeah. I understood that, but couldn't say anything intelligent myself. Just past my solid knowledge thing.

The permittivity of the skull ...

... I know the feeling ....

What... inability to learn?

No, inability to say anything.

[relocates jaw]

Where did you put it?

It had been behind the fridge, and I went to get some ice and noticed the fridge was further out than usual, and sure enough, there it was, nestling in the cooling fins.

What, your jaw??

Um, well, my jawbone and the teeth in it, and obviously my tongue.