3.1127 energetic photons and magnetic fields (28)

Willard McCarty (MCCARTY@vm.epas.utoronto.ca)
Fri, 2 Mar 90 22:40:46 EST

Humanist Discussion Group, Vol. 3, No. 1127. Friday, 2 Mar 1990.

Date: Fri, 2 Mar 90 08:47:48 EST
From: "Dana Cartwright, Syracuse Univ, 315-443-4504" <DECARTWR@SUVM>
Subject: X-Rays Harmful to Laptops?

I'm curious as to the origins of the notion that x-rays (from whatever
source) will erase magnetic disks. It seems implausible, somehow.
X-rays are highly energetic photons, but are otherwise just like visible
light (which is also photons, just less energetic). Now, camera film
is designed to react to light, and it's not terribly surprising that it
also responds (rather well, in fact) to the more energetic photons of

But surely magnetic disks are not particularly sensitive to light, right?
Shining even a very bright light on a floppy disk, for example, doesn't
seem likely to erase it (this is an appeal to one's intuition, clearly,
not an appeal to the laws of nature). So, why do we (all) seem to think
that x-rays would erase disks? I'm well aware that the readers of this
list are humanists, not physicists. Do we have access to an expert who
can shed serious light on this subject?