from the need-better-than-a-jar dept.
Roland Piquepaille writes "In 'Shooting the moon,' the San Diego Union-Tribune describes how and why physicists from UCSD are using lasers to send light pulses in direction of an array of reflectors installed on our moon in 1969 by Neil Armstrong and Buzz Aldrin. One of the goals of these experiments is to check the validity of Einstein's theory of general relativity. Another one is to measure the distance between the Earth and moon with a precision of one millimeter by catching photons after their round trip to the moon. But it is amazing to realize how difficult it is to capture photons after such a trip. I also have up a summary, which contains additional details and pictures, if you just want to learn how difficult it is to capture photons back from the moon."
PL/I -- "the fatal disease" -- belongs more to the problem set than to the
-- Edsger W. Dijkstra, SIGPLAN Notices, Volume 17, Number 5