11 Dec
2000
11 Dec
'00
8:14 a.m.
Eric Smith wrote:
But why would it appear concave from the label side, and convex from the
data side?
I believe that
the tracks on a CD are concentric rings,
which would make a CD something of a reflective Fresnel lens.
It's a single spiral groove, but the macroscopic optical effects are
probably similar.