the.com/blink comparator
the machine that caught the sky lying, one flickering photo at a time.
means a device that rapidly alternates between two photos of the same star field so anything that moved between exposures appears to jump.
from built in the early 1900s by Carl Pulfrich at Zeiss for measuring plate photographs, it found its killer app in astronomy: Clyde Tombaugh used one at Lowell Observatory in 1930 to spot Pluto twitching against fixed stars.
pluto discoverytombaugh found it after a week of blinking plates
how it worksalternates images fast enough to trick the eye
still usedamateur asteroid hunters use software versions today
pre-digitalpredates computers finding moving objects automatically