Neutrino Comm Links
The search for extraterrestrial intelligence assumes that ET will be communicating using photons. But despite decades of listening out, we’ve heard nothing.
But today, John Learned from the University of Hawaii and pals say forget photons. We should be looking for evidence of ET using neutrinos.
The reason is that any civilisation advanced enough to colonise the galaxy would need a reliable way to communicate over intragalactic distances and photons simply don’t pass muster.
I don’t know that there’s any “evidence” here (see the PDF file in the abstract), but Learned, Pakvasa and Zee provide a plausible argument that any successful “galactic” civilization must, of necessity, communicate via something other than photons, and that, considering the physics of the problem, it’s reasonable for them to do so using neutrinos. This doesn’t immediately address the Fermi Paradox problem, which is itself an argument against the idea that a large number of stars in the universe automatically produces a large number of “galactic” civilizations. If that was the case then we should expect to see artifacts and evidence of that, even if it’s only happened a few times. It does, however, start to address the idea that the number of civilizations that we will detect is strongly affected by how they communicate, both directly and indirectly. They have to do it pretty well!
They’re elusive, but even our technology is getting to the point where some think using neutrinos for communication is feasible.
Current plans for neutrino generation coupled with prospective abilities for neutrino detection are beginning to make feasible neutrino messages we might send to be detected at the distances of nearby stars. Though neutrino beams are expensive to generate, this disadvantage may be outweighed by such advantages as very narrow focusing of the transmitted neutrino beam, and the ability to receive from the whole sky simultaneously over a broad range of neutrino energies.
On earth, neutrino communications have lagged radio communications by about 100 years, during which time our ability to send and receive radio signals has increased drastically. We can hope for similar improvements in neutrino communications in the next decades.
That’s optimistic, but not impossible.