PARTICLE physics is all very well for addressing trivial matters like “why are we here?” (see article). But some people question its practical usefulness. To answer such naysayers a group of physicists at Fermilab have just submitted a paper to Modern Physics Letters A in which they describe how they have built themselves a neutrino-powered telephone.

Naturally, their neutrinophone is digital. A pulse of neutrinos (small, elusive subatomic particles with no electric charge) corresponds to the digit “1” while no pulse corresponds to “0”. The neutrinos themselves are created by smashing bunches of protons into a target made of graphite. They are detected roughly 1km away by researchers who, in their day jobs, work on a neutrino collaboration called MINERvA. By modulating the pulses of protons the group was able to send a message in binary that, when translated, read “neutrino”. Whether this will go down in history alongside Alexander Graham Bell's first message, “Mr Watson, come here, I want to see you,” remains to be seen.

The point, though, apart from sheer wackiness, is that neutrinos are not easily intercepted by collisions with other sorts of matter. If humanity wanted to broadcast its existence to intelligent life forms that might be out in the galaxy listening, a modulated beam of neutrinos would be a good way of doing so. Conversely, some people argue that listening for ET at radio frequencies is the wrong approach. The right one, they think, would be to build a neutrino-receiver. And that would mean plenty of work for neutrino physicists. Perhaps, then, from its makers' point of view, the neutrinophone is not such a nutty idea, after all.