The Neutrino Hunters by Ray Jayawardhana
For those without an advanced degree in science jargon, neutrinos are elusive, tiny, tiny, tiny, tiny little particles who rarely interact with matter. MATTER of fact… *pause for laughter, followed by immense self-loathing*… trillions of neutrinos pass through the human body each second, and have done so every day from the moment we were born and will continue to the day we’ll die. Alarmed yet? Don’t be.
Neutrinos are byproducts of the nuclear reactions that fuel our sun (and the rest of the stars in the Universe) and they, like the neutron, have no charge. They are sort of like the Switzerland of atomic particles; small, neutral, and come in three flavors. (Wait, what?) Neutrinos are way smaller than other subatomic particles like the neutron or proton, but almost never interact with any matter, which, incidentally, is why we haven’t noticed the approx. quintillion neutrinos that have passed through your body in your lifetime.
The Neutron Hunters in a superb mix of biography and science and covers the neutrino’s history; how its existence was initially postulated, how it came to be detected and what can be learned from them. It’s a massive subject but aptly abridged to approx. 200 pages and could have easily been longer. I seem to be finding it more and more as a fault with books that they aren’t as long and detailed as I would have wished. (Maybe because I’m also reading Harry Potter and The Order of the Phoenix concurrently).
In his book, Jayawardhana visits massively ambitious laboratories built for the sole purpose of detecting neutrinos. These massive detectors are mostly built in abandoned mines where small, underground lakes are created; filled with various funny substances, such as dry cleaning fluid that neutrinos, on rare occasion, interact with to form new elements which are then detected. These neutrino events are few but give us nonetheless accurate depictions of their multitude as well as their origins.
We also travel to IceCube in Antarctica… which apparently is an actual place, where long steel cables with sensitive phototubes are buried deep into the ice to trace the paths of newly liberated neutrinos by observing other strange particles called muons. (Muons are 200 times heavier than electrons but way less abundant due to their lack of stability).
An info-graphic of the IceCube neutrino observatory.
In my opinion, the most enjoyable passages in the book follow the exploits of Wolfgang Pauli and Bruno Pontecorvo, respectively. Pauli was a brilliant physicist who postulated the existence of neutrinos to account for the differences in masses of radioactive elements and the products of their decay. Pauli himself said that he had done a terrible thing. He had postulated a particle that couldn’t be detected.
The story of Pontecorvo, however, is something straight out of a spy novel. He had theorized how to actually detect the shy neutrinos by an indirect observation. See, when a neutrino collides with a Chlorine atom (a rare event, but just so that we can observe a few of them), a radioactive Argon atom is formed. (Chlorine and Argon are next-door neighbors in the periodic table so if we change a neutron in a Chlorine atom to a proton, by colliding it with a neutrino, the Chlorine atom becomes an unstable Argon isotope that subsequently decays). By observing the radioactive decay of the Argon atom, we indirectly observe the work of the neutrino.
Okay, so a down quark in a neutron turns into an up quark, to form a proton, which triggers the release of an electron and an anti-neutrino, which is pretty much the same as a neutrino. Okay?Yeah, uhm. Particle physics is really friggin bizarre.
But Pontecorvo’s story is much more elaborate. He flees the increasingly fascist regime in Italy to the U.S. There he is not trusted due to his socialist leanings. He then takes up a professorship in Liverpool, England, but instead of returning there from holiday in Italy, he flies with his family to Stockholm, Sweden, then Helsinki, Finland. And that’s when he disappeared. Later, it was revealed that he defected to the Soviet Union. Like I said. Spy novel, only true.
The book is enjoyable and informative all throughout and through another of its countless anecdotes of scientists, it introduced to me an insult that I’m going to start taking up. “A spherical bastard”. I.e. a bastard seen from all sides. If anything, I’m going to start adding ‘spherical’ in front of all my name callings. E.g. spherical fart goblin, spherical demon toilet, etc.
Like I said, I would have liked some of the science-y parts of the book to be a little more elaborate, but this is a solid read for anyone interested in modern science in general, and especially, the hunt for neutrinos.