Users that often use this tag:
darainwa (2)

Does relativity have any practical significance? In fact, relativity had to be taken into account by the designers of the Global Positioning System. The GPS satellites are affected both by special relativity (since the satellites are moving, clocks aboard them appear to run slower as seen from the ground), and by general relativity (since the satellites are farther away from the mass of the earth, clocks appear to run faster as seen from the ground). The net effect of both is that clocks aboard GPS satellites would gain 38 microseconds per day relative to the ground, if relativistic effects were not corrected for--a figure which can be confirmed by using Google calculator.
posted by DevilsAdvocate on Nov 30, 2004 - 26 comments

MSNBC's Robert Wright seemes confused in this story about the Global Positioning System. He misinforms the reader about how terrorists can now use the military's encrypted GPS signals for more accurate positioning. (FYI: you are still unable to use the military's encrypted GPS signals, contrary to what Wright claims.)
more inside>>
posted by darainwa on Jun 28, 2000 - 2 comments

Advertising on Your GPS Reciever It looks like advertisers are already dreaming up new uses for the higher quality GPS signals.

"You're walking down the block, your phone goes off as you pass every store and tells you that there's a 50-percent-off sale." Someone remind me why it was a good idea to deregulate the GPS?
posted by darainwa on May 27, 2000 - 4 comments