In message <06013AA10880459380352E3FB29C4B5C@pc52>, "Tom Van Baak" writes:
>2) Can you imagine applying this entire process in reverse. That >is, instead of using GPS to timetag lightning strikes, use lightning >strikes to synchronize a global network of local clocks. The first input you need is the exact longitude/latitude of the lightning bolt. The easiest way to do that is with a set of GPS synchronized receivers, aaaand we're back to sqare one! The next issue is that lightnings are seldom vertical, they can trivially wiggle many hundred meters sideways, so at absolute best your jitter is going to be no better than the microsecond domain, and probably much worse, increasing with distance. But there's a workaround: if you have the right kind of "pregnant" thundercloud overhead, a plain firework rocket trailing a thin grounded wire will, on your command, get you a lightning strike. Not only are these lightnings almost always entirely vertical, they are also particular sharp and potent (for that very reason). So if you live in the right kind of place, you *could* implement a daily clock synchronization service much more spectacular than a mere "ball-drop". I belive the US electrical grid industry runs a joint research center somewhere in northern Florida, using this method to test lightning protection of the power grid components. I suspect they ignite their rockets using remote control. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.