Laboratory of Cold Atoms Near Surfaces


Paper in Physics Education

Popular science article Should we bother with the speed of light in everyday life? A closer look at GSM technology has been published in Physics Education. It may be downloaded from the publishers website:

Phys. Educ. 47 (2012) 579-583

or directly here.

The speed of light, or more generally, the speed of electromagnetic waves, seems to be incredibly high. 300 000 km s−1 is far greater than the typical speed of a car, a plane or even a rocket, which is just several kilometres per second. It is thus natural that we treat the speed of light as infinite in everyday life. It appears, however, that even such a high but finite speed causes problems that have to be solved in one of the most popular electronic devices—cellular phones. Here we look more closely how the global system for mobile communications (GSM) phone works and how it deals with the speed of electromagnetic waves.