UCL in the News: Seabed particle hunt could shed light on the dawn of time

By detecting neutrinos, scientists hope to shed light on the origins of cosmic rays and learn more about the structure of the universe soon after its violent birth. …

Scientists calculate that while a few are likely to strike a single square kilometre of the planet every year, the threat they pose to human health is minimal.

"The chance of being struck by one of these things is extremely small. And even if you were unlucky, you'd not feel anything at all because the energy would be dissipated through your body. You wouldn't feel a sudden punch in the stomach," said Dr David Waters [UCL Physics & Astronomy], a scientist on the UK project, the Acoustic Cosmic Ray Neutrino Experiment. …

Computer models used by the team at UCL have given the researchers a good idea of what a neutrino collision in the ocean should sound like. In the trials, they will head out over the submarine trench near Rona, lower an underwater microphone into the water and play the neutrino soundwave. If hydrophones tethered to the seabed beneath pick it up, they will have proved, at least in principle, that they could hear a neutrino when it crash lands in the sea. …

The researchers have already identified an unlikely culprit that could scupper the trials. …

Earlier recordings from the hydrophones … also recorded an annoying species of snapping shrimp, that blasts out rapid clicks at exactly the same frequency where the neutrino is expected.

"Fortunately, they click all the time, so we should be able to filter them out," said Simon Bevan [UCL Physics & Astronomy]. …

If the trial is a success, it will pave the way for a much larger experiment that would use hundreds or thousands of hydrophones to hunt for neutrinos in a much larger volume of water. …

" Observing the universe in neutrino light is really the first time we'd be able to do astronomy with something other than electromagnetic radiation, and who knows what we will see, because large parts of the universe are opaque to light and we can't see what's going on there. These particles zip straight through things and they may be a way for us peer into parts of the universe we cannot otherwise see," said Dr Waters.

Ian Sample, Guardian Unlimited