Cosmic Neutrinos Have Been Confirmed To Exist

IceCube Obsevvatory finds Neutrinos
This is one of the highest-energy neutrino events from a survey of the northern sky superimposed on a view of the IceCube Lab at the South Pole. Credit: IceCube Collaboration

 

Cosmic Neutrinos – so what the heck are they?

When I was in high school, it was difficult enough to understand protons, neutrons and electrons.  Add in a periodic chart, and with some valance numbers you could actually figure out the relationship between the various elements.  At least for the ones we understood at the time.

Then science got crazy.  Smaller particles like pions were found, and then even those were discovered to be made up of even smaller particles like quarks and mesons.

And then came the neutrino.  A charge-less, nearly mass-less particle that isn’t affected by much of anything, (and therefore extremely difficult to detect), was theorized.  It is so unaffected by it’s surroundings that it even passes through the stuff you and I are made of , and the things around us without being slowed down or even detected.

Even more interesting is it is thought to be the stuff of dark matter (or at least part of it).

But theorize no more as it appears the IceCube Observatory has confirmed the existence of cosmic neutrinos.

The IceCube Lab

This graphic depicts the IceCube Neutrino Observatory’s sensors, which are distributed over a volume of 1 cubic kilometer of clear Antarctic ice. Under the ice, 5,160 DOM sensors operate at depths between 1,450 and 2,450 meters. The observatory includes the densely instrumented subdetector DeepCore and a surface air shower array, called IceTop. Credit: IceCube/NSF

 

And that is the subject of the article that follows.  It is well worth a read and a share …

Millions of light-years away, a star explodes as a supernova and sends a host of subatomic particles called neutrinos in all directions. One of these heads towards our Solar System and, after millions of years, this tiny neutrino enters Earth’s atmosphere and collides with an atom inside a detector below the ice of Antarctica. The detectable signal produced not only confirms the neutrino’s existence, but also indicates where it has come from.

This is the amazing process that has now been confirmed to be taking place by the IceCube Collaboration in Antarctica. Neutrinos, nearly massless high-energy particles with no charge, are known to have sources here on Earth and in the Solar System, such as the Sun. But astronomers wanted to prove that they were also created elsewhere in the universe, covering vast distances of the cosmos. Now, they have that proof – and these neutrinos could act as subatomic signposts to exotic phenomena. The results are published in the journal Physical Review Letters.

…… The neutrinos were found by detecting 21 ultra high-energy muons. These are secondary particles created when neutrinos bump into other atoms. As neutrinos are almost massless, they are incredibly hard to detect aside from spotting these muons.

To detect them, the IceCube Observatory uses thousands of optical sensors beneath the ice at the South Pole. It can spot the muons because they move faster than the speed of light in a solid. Note that the speed of light isn’t being broken here – rather, light changes speed depending on what medium it is traveling through. In a vacuum it travels at its limit, but in things like glass and ice it travels slower. But muons are not limited in this way; they travel faster through matter, producing noticeable Cherenkov radiation – a light wave produced in their wake, similar to a boat moving through water.

The importance of finding the cosmic neutrinos is that they might point towards exotic phenomena in the universe. While we mentioned that they can form in supernovae, they are also thought to orginate in black holes, during star formation and elsewhere. But no single source has been found as the main culprit of neutrinos, something that might be discovered with future research.

 

To read the full article, please visit IFL Science

Cover Photo: This is one of the highest-energy neutrino events from a survey of the northern sky superimposed on a view of the IceCube Lab at the South Pole. Credit: IceCube Collaboration