Comments on: Not Science Fiction

By: Lab Lemming

Lab Lemming — Sun, 17 Feb 2008 01:13:30 +0000

So was this formulated before or after positrons were discovered?
’cause, what the science fiction antimatter promoters never seem to remember is that bananas produce antimatter from e+ decay of 40K.
Of course, since the electron capture and b- decays are much more common, your average banana only cranks out one positron every 2 hours. If you want one to appear during a 50 minute university lecture, you should probably bring a whole hand to class.

By: theresa f

theresa f — Sat, 02 Feb 2008 23:50:07 +0000

wow, that’s intense. haha i’m going to have to take a break, then come back and read it again …looking forward to hearing the BBC anti-matter conversation!

By: Aaron F.

Aaron F. — Fri, 25 Jan 2008 01:49:01 +0000

Oh, cool! Thanks, EJ! And, uh, I’m pretty sure Ambitwister’s comment wasn’t there when I posted my second one…

By: EJ

EJ — Tue, 22 Jan 2008 19:33:07 +0000

The way it’s written now is for a “free” particle. Just replace the zero on the right-hand side with E*psi, or for arbitrary potential V(x) use (E - V(x))*psi.

By: Aaron F.

Aaron F. — Tue, 22 Jan 2008 15:45:49 +0000

But wait… I don’t see anything that looks like a potential! Where does the potential term go if you want to solve for, say, an electron in a box?

By: Aaron F.

Aaron F. — Tue, 22 Jan 2008 15:39:13 +0000

Ohhh… now I see that the gamma^mu are actually the Dirac matrices in disguise. Tricky tricky!

By: Ambitwistor

Ambitwistor — Tue, 22 Jan 2008 15:37:39 +0000

Aaron: no, the gamma^mu aren’t relativistic dilation factors, they’re Dirac matrices.

By: Aaron F.

Aaron F. — Tue, 22 Jan 2008 15:35:14 +0000

That’s the Dirac equation? I thought it was supposed to be complicated! Am I to understand that gamma^mu = 1/sqrt(c^2 - v_mu^2), as usual?