Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: X-Ray vision



At 11:34 PM -0800 3/30/00, Digby Willard wrote:

No. The Meissner effect is a DC effect anyway. Do you suppose
that superconductors can thwart Superman's x-ray vision?!
(Before you ask, Kryptonite is not superconducting.)

Don't know about superconductors. Lead can thwart Superman's x-ray vision.
It can also protect him from the effects of kryptonite.

Contrary to what the comic books tell you, lead is not a magic material.
It just packs more electrons per unit volume than most materials. As an
x-ray shield tungsten is better, and osmium is probably the best - per
unit thickness! After all, air is also opaque to x-rays - in thickness
ten tonnes per square meter.

In my graduate student days I used to pass far infrared radiation
through superconducting lead 'most every day. Of course the lead was
only about 70 angstroms thick!

Leigh