BELIEVE   ME   NOT!    - -     A   SKEPTICs   GUIDE  

The Speed of Light

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 [$\mu$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!