Archive for May 9, 2012

Dielectric Breakdown

Posted in The Universe and Stuff with tags , , on May 9, 2012 by telescoper

This is the season when our  second-year students are picking the projects they want to do in their third year, as are those third-year students intending to carry on for Year 4 of the MPhys programme. I’ve been chatting to quite a few students about this particular project so thought I’d do a quick post here.

One of the third-year projects I’ve got in the current catalogue for next year concerns a computer model of dielectric breakdown based on the idea of diffusion-limited aggregation. This is  a neat model that allows the students to simulate pretty patterns like the one shown on the left.

The mathematics of it was first presented in Niemeyer, L., Pietronero, L., Wiesmann, H., “Fractal dimension of dielectric breakdown,” Physical Review Letters 52 (1984), 1033-1036.

Dielectric breakdown happens when a sufficiently large voltage is applied across a material that doesn’t normally conduct electricity, the classic example being a lightning strike. Here’s another example, which I find particularly electrifying…

Classical physics can be fun, you know!

Song on a May Morning

Posted in Poetry with tags , , on May 9, 2012 by telescoper

Now the bright morning-star, Day’s harbinger,
Comes dancing from the East, and leads with her
The flowery May, who from her green lap throws
The yellow cowslip and the pale primrose.
Hail, bounteous May, that dost inspire
Mirth, and youth, and warm desire!
Woods and groves are of thy dressing;
Hill and dale doth boast thy blessing.
Thus we salute thee with our early song,
And welcome thee, and wish thee long.

by John Milton (1608-1674).