Answer to Question #19381 in Optics for baran

Question

if superman really had x-ray vision at 0.12nm wavelength and a 4.3mm pupil diameter,at what maximum altitude could he distinguish villains from heroes, assuming the minimum detail required was 4.8cm?

Answer 1

Assuming the pupil to beround, the angular resolution is
sin(angle) = 1.22*wavelength/diameter;
where angle = sin(angle) = detail/distance assuming the distance is much
greater than the detail.
Thus,
distance = detail*diameter/(1.22*wavelength) = (4.8 cm)*(4.3 mm)/(1.22*0.12 nm)
= 1410 km.

Answer: 1410 kilometers.