How scientists unlock secrets of the universe from deep underground – by Erica Caden (The Conversation.com – November 28, 2017)

http://theconversation.com/

What do a big chunk of ice at the South Pole, a mine in northern Ontario and a mountain in Italy have in common? They’re all home to extreme underground environments but they’re connected in another, more unexpected way. All three are host to large physics experiments searching to understand and answer the most basic questions about the world around us.

As a research scientist at SNOLAB in Sudbury, Ont., I get the chance to talk to a lot of different people about the work we do. The question often comes up: Why are we doing astrophysics — the study of space and the cosmos — from deep underground?

In particle physics, we long ago answered all of the questions that could be answered through tabletop experiments run by small groups of scientists in small laboratory spaces. Albert Michelson and Edward Morley showed that “luminiferous aether” didn’t exist, using a light source and mirrors on a bench-top stand. Marie Skłodowska Curie discovered polonium and radium in a shed next to the school of chemistry and physics at the École Normale Supérieure in Paris.

Fortunately, or unfortunately, we’re now asking bigger questions — we are looking for the nature of the universe: What gives particles their mass? What kind of particle is the neutrino? What is the rest of space made of? What is dark matter? Bigger questions require bigger experiments, which need bigger groups of people making them function.

The way to answer these questions is not just to build bigger detectors, but also to think carefully about where we put these detectors. So, scientists build detectors deep underground. We use kilometres of the earth as a dense shield to stop the particles we don’t want to detect.

For the rest of this article: http://theconversation.com/how-scientists-unlock-secrets-of-the-universe-from-deep-underground-86279