1420 megahertz

In the Next Generation episode “Galaxy's Child,” the Enterprise stumbles upon an alien life-form that lives in empty space, feeding on energy. Particularly tasty is radiation with a very specific frequency 1420 million cycles per second, having a wavelength of 21 cm. In the spirit of Pythagoras, if there were a Music of the Spheres, surely this would be its opening tone. Fourteen hundred and twenty megahertz is the natural frequency of precession of the spin of an electron as it encircle...

 Our Radio Broadcasts into Space are a Monologue

Some individuals find the absence of a dialogue distressing – as if meaningful dialogues were commonplace on this planet. Philip Morrison, of the Massachusetts Institute of Technology, has pointed out that such cultural monologues are entirely common in the history of mankind; that, for example, the entire cultural patrimony of classical Greece, which has influenced our civilization in a profound way, has traveled in only one direction in time. We have not sent our wisdom to the Greeks. The...