The speed of light is so enormous (299,792 km/s) that we scarcely
notice a delay between the transmission and reception of electromagnetic
waves under normal circumstances. However, the same electronic technology
that raised all these issues in the first place also made it possible
to perform timing to a precision of millionths of a second
(microseconds [s]) or even billionths of a second
(nanoseconds [ns]). Today we routinely send telephone signals
out to geosynchronous satellites and back
(a round trip of at least 70,800 km) with the result that we often
notice [and are irritated by] the delay of 0.236 seconds or more
in transoceanic telephone conversations. For computer communications
this delay is even more annoying, which was a strong motive for recently
laying optical fiber communications cables under the Atlantic and Pacific
oceans! So we are already bumping up against the limitiations of the
finite speed of light in our ``everyday lives'' (well, almost)
without any involvement of the weird effects in this Chapter!