Question: what do we use to find out about particles

Claire Lee answered on 27 Jun 2013:

Lots of things! Particles are really really small so we can’t see them, so we have to be clever about detecting them.

We have big particle detectors which are really a sort of digital camera – at least the ones we use today. Back in the 60’s they had these things called bubble chambers – which really was a big tank of gas. If a particle moved through the gas it would leave a little path, and what physicists noticed was that tiny bubbles formed along this path. So they would literally wait a while for some particles, then take photograph of the gas and bubbles, develop the film, and then sit with a pencil drawing along the lines of bubbles 🙂 Here’s a picture: http://www.interactions.org/cms/?pid=2100&image_no=FN0143

Now today we have better technology so things are electronic. But the principle remains the same – get a particle to go through something, and look at what it leaves behind. Sometimes a particle can leave behind electric charge, which can give us an electric signal. Sometimes it leaves behind light, which we can detect. In fact, all our fancy detectors are just different ways of putting these two basic methods together in clever ways 🙂

ATLAS has some nice videos on this – here is once where they describe nicely how we detect particles with our particular detector:
http://www.atlas.ch/multimedia/#episode-2