As I promised, today I'll tell you about CERN, because I visited it last Saturday.
CERN is the European Organization for Nuclear Research. It is an international collaboration, formed by most european countries, and many more. Although the name has not changed since its foundation, it's currently more devoted to research in particle and fundamental physics than "nuclear" itself. Many different experiments are carried over at CERN, although the most expensive, best known, and most impressive is LHC, which is a 27-km-long tunnel buried across the french-swiss border near Geneva. In it, particles are accelerated up to, almost, the speed of light (they travel the whole tunnel more than 11,000 times every second!). From time to time (40 million times every second), the scientists at CERN make these particles collide, and then try to measure all the "debris" from that explosion. The analysis of this gives physicists very valuable information about how our universe works. But you can't just take a picture with your camera of this explosion... they had to make enormous detectors that record very carefully everything that has happened. It is one of these detectors, CMS, that I visited on saturday.
CMS means Compact Muon Solenoid... but it is very big! It is in a cavern underground, 90 metres deep... This is like a 30-floor building. Fortunately, there's an elevator! Near the cavern where the detector is, there is a smaller cavern that houses all the computers and electronics needed to control the operation of the detector, and to store all the data that it generates. There are lots of aisles full of computers:
And also many other scientific equipment:
These computers generate so much heat that they have to put huge fans to cool them:
This is the "old" control room, from where they made sure that everything was working fine when they built the detector.
With so many computers, you need lots of cables to move the data from here to there, so this is how the space between floors looks like...
Safety is taken very seriously: there are lots of cabinets with protective equipment.
This is how the 27-km-long tunnel looks like... unfortunately we couldn't visit it, but they have a nice poster to get an idea.
And here is one photo of the detector... doesn't it remind you of an spacecraft from "Star Wars"?
And,, finally, here I am in front of the detector, with the guide that showed us everything.
