Neutrinos are fascinating. They aren’t in another dimension, per se, but they act like they are only barely here. They are as numerous as light particles, but unlike light, they interact only very rarely and randomly with mass, passing through everyone and everything at what seems to be the speed of light. Ghostly neutrinos, with no charge and almost no mass would “zip through a million miles of lead without skipping a beat” and billions of neutrinos are zooming through you right now.
Every second about 65 billion solar neutrinos pass through every square cm of Earth! Billions are zooming through you right now. Because they do not interact with your atoms, you don’t sustain any damage to your cells. – SciExplorer
What are neutrinos?
A neutrino is a fermion [matter particle] that interacts only via the weak subatomic force and gravity. The neutrino is so named because it is electrically neutral and because its rest mass is so small that it was long thought to be zero. The mass of the neutrino is much smaller than that of the other known elementary particles.
The Nobel prize in Physics 2015 was awarded to both Takaaki Kajita and Arthur B. McDonald for their experimental discovery of neutrino oscillations, which demonstrates that neutrinos have mass. – Wikipedia
Neutrinos dart through matter and space at a pace indistinguishable from the speed of light, so they were initially thought to be massless. – Aps.org
… the Sun emits an enormous flux of neutrinos. So, during the day, “solar neutrinos” stream down on us, and at night, they stream up at us, having rained down on the other side of the earth and passed entirely through it. There are two other kinds of neutrinos hitting us all the time. The universe is filled with neutrinos—roughly the same number as there are particles of light. These come at us equally from every direction. There are also lots of neutrinos produced in the atmosphere when highly energetic particles (e.g. protons) from outer space (“cosmic rays”) impinge upon the earth, as they do in copious quantities. These are the so-called “atmospheric” neutrinos”. – FirstThings
Can we detect cosmic neutrinos?
Catching a glimpse of even regular neutrinos – low-energy particles generated in the atmosphere – is difficult enough, but spotting a “cosmic neutrino” left over from the Big Bang has been downright impossible. That is until this cubic kilometer buried under Antartica’s frozen wastes started looking.
Known as the IceCube Neutrino Observatory, this $279 million telescope is located under the Amundsen-Scott South Pole Station in Antarctica. Since its completion in 2010, IceCube has been searching for evidence of the cosmic neutrino via an array of thousands of sensors hung in cascading lines under the ice.
Just as its predecessor, the Antarctic Muon And Neutrino Detector Array (AMANDA), did, IceCube consists of spherical optical sensors called Digital Optical Modules (DOMs), each with a photomultiplier tube (PMT). In all, 86 strings containing 60 DOMs apiece and a total of 5,160 PMTs have been hung a depths ranging from 1,450 to 2,450 meters. IceCube researchers leveraged a unique hot water drill to quickly bore through the ice when installing the array.
When a weakly-interacting neutrino does manage to strike the nucleus of an atom in the ice, the resulting energy release creates a brief flash that is picked up by the DOM and transmitted to a data collection station on the surface. The system detects roughly 100,000 neutrino strikes annually but, until last month, all of them were of the atmospheric variety. In April, IceCube detected a pair of strikes – nicknamed Bert and Ernie – with energy signatures in the TeV range, suggesting an extraterrestrial origin. Since then, the system has spotted an additional 26 potential cosmic neutrino strikes.
The data must still be analyzed and verified by the scientific community but if these really are what researchers think they are, we could soon gain new insight into conditions present mere seconds after the Big Bang.
Welcome to Earth, neutrinos from the cosmos.