What is it and why go to so much trouble to make it? It is a
circular tube 27Km in diameter containing absolutely nothing at
all. In fact it contains fewer molecules per cubic metre than in
interstellar space. It is the 'nothing' that the scientists are
really interested in.
It seems that if you shake a tiny area of empty space with
enough energy it will produce stuff. This stuff is particles. The
more energy you whack your tiny bit of empty space with, the more
particles it produces.
The LHC is a machine with two parts: one produces and focuses
the energy. This is the accelerator; this part of the tube is
surrounded by magnets. This takes protons, neutrons and electrons,
stuff we are familiar with, and accelerates it up to colossal
speeds. Over 99.99% of the speed of light.
If two particles moving in opposite directions collide, then you
have an energy density not seen in the universe since the big bang.
For a tiny fraction of a second, an unimaginably small bit of
emptiness in the tube is heated to well over
1,000,000,000,000,000oC. This is really hot, hotter than the centre
of the hottest stars. This gives the empty space an almighty shake
and bits of matter fall out.
The second part of the machine, the detector, works out what
these bits are. The detector is about the size of St. Pauls
Cathedral and contains the equivalent computing power of a
medium-sized city.
All clever stuff, but why is it so important? To really 'get'
this we have to realise that what we are interested in is actually
the empty space in the tube, not the particles. The key question is
how does a tiny piece of complete vacuum, absolutely nothing at
all, know how to produce a particle? This is the plan that is built
into the structure of space itself. This is where all the particles
that make us up, and the entire known universe, came from.
Nothing.
What we are trying to discover is how nothing at all knows how
to construct a universe. This could turn out to be quite
important.