"Use the rear view mirror to imagine telling someone just twenty five years ago about GPS."
People _did_ tell each other about GPS twenty five years ago. Twenty five years ago it was a decade old working navigational system. Some of the ubiquitous futuristic technology we have is older than one might think.
While the ideas behind it were developed much earlier, GPS didn't become fully operational until 1995 [1].
It's also worth noting, on the other hand, that the (not yet fully operational) system was used during the first Gulf War. [2]
[1] http://tycho.usno.navy.mil/gpsinfo.htmlThe U.S. Air Force Space Command (AFSC) formally declared the GPS satellite constellation as having met the requirement for Full Operational Capability (FOC) as of April 27, 1995.
People _did_ tell each other about GPS twenty five years ago. Twenty five years ago it was a decade old working navigational system. Some of the ubiquitous futuristic technology we have is older than one might think.