"Antarctic ice turned into a telescope": the Nobel Prize in Physics laureate announced
Belgian-American scientist Francis Halzen has been awarded this year's Nobel Prize in Physics for his decisive contributions to the IceCube Neutrino Observatory and the discovery of high-energy neutrinos of astrophysical origin. I talked about it on the LRT TV show "Laba diena, Lietuva" ("Good Afternoon, Lithuania").
The interview is in Lithuanian. If the video doesn't show, watch it on LRT: "Antarctic ice turned into a telescope" – "Laba diena, Lietuva"
What was the prize awarded for?
Neutrinos are among the most elusive particles in the Universe: they barely interact with matter, so billions of them pass through the Earth and through each of us every second. That is exactly what makes them excellent messengers — they travel from the farthest corners of the cosmos without being deflected or absorbed, carrying information about the most powerful processes in the Universe. But to catch even a few of them, you need an enormous detector.
Back in 1988, Halzen proposed a bold idea: use the ice of the South Pole itself as the detector. This became IceCube — more than 5,000 light sensors embedded in a cubic kilometre of exceptionally clear ice, 1.5–2.5 km deep. When a rare neutrino does hit an atom in the ice, the resulting particles emit a faint blue (Cherenkov) light, from which the neutrino's energy and direction of arrival can be reconstructed. The observatory became fully operational in 2010, and in 2013 it detected, for the first time, high-energy neutrinos coming from beyond the Solar System. Later it identified their first sources — a distant active galaxy (a blazar) and the galaxy NGC 1068 — and even produced an "image" of our Milky Way in neutrino light. This opened a new window onto the Universe: neutrino astronomy.