x-rays to peer into the human
body was a major milestone in
modern medicine. Wilhelm
,1845-1923) discovered the
portion of the electromagnetic
spectrum that he called “x-rays”.
X-ray wavelengths range from 0.1
to 10 Angstroms compared to 4000
to 7000 Angstroms for visible
In its simplest form, the wave
equation refers to a scalar quantity
u that satisfies
is a fixed constant equal to the
propagation speed of the wave.
first proposed the wave nature
of visible light.
Cormack (South African,
1924-1998) laid the mathematical
foundation behind what we know
as the CAT scan (Computed Axial
Tomography). The theory is based
on the mathematical question,
“can we reconstruct a body
if we can compute all of the line
integrals that pass through it?”.