Dark matter makes up almost everything that
there *is*.
But we can't see it.
86% of the matter we think the universe is
made of doesn't interact with the sort of
matter we're made of.
That's why we call it dark, because we can
see that it should be there, but it isn't.
Which might actually mean that it's not there,
and something else is.
But at the moment, dark matter is our best
guess.
It's one of the driving forces of the universe,
the force which gives galaxies enough mass
to stop them from spinning apart.
And like gravitational waves and the higgs
boson, it seems we could be pretty close to
finding dark matter, and filling in one of
the biggest holes in our understanding of
the cosmos.
And the most likely place to find it?
A chamber a mile down a mineshaft in South
Dakota, once home to gold prospectors.
Now home to dark gold prospectors.
Or the LUX experiment.
Many people are searching for dark matter,
but LUX is seen as one of the most promising
experiments.
It's a highly sensitive array designed to
detect WIMPS, Weakly Interacting Massive Particles.
The idea is that Dark matter must be particles,
because it's matter, and there are billions
of them streaming through the Earth every
second, because they make up over 80% of the
weight of the universe.
But they very rarely bump into regular matter,
and when they do, they only have the tiniest
interaction with them.
LUX features a vast chamber filled with liquid
Xenon, which flashes when particles interact
with it, and a detector array designed to
be sensitive enough to pick up those interactions.
It has to be a mile under the urface to filter
out cosmic rays, which would interfere with
the experiment.
And the people behind it are pretty confident
it'll work - Lux has been confirmed as the
most sensitive experiment of its kind and
although it's 90 day calibration and shakedown
run didn't detect anything, but the team say
they are confident that, if anything is out
there, they should pick it up at least once
on their upcoming 300 day run.
That won't be enough to confirm dark matter
on its own, it'll need to happen repeatedly
to be considered proof that a new particle
has been found.
Having said that, LUX isn't the only experiment
out to prove, or disprove, the existence of
dark matter.
The large Hadron Collider's having a go too,
by creating it's own dark matter in particle
smashing experiments, and various space-based
tests are also looking for tell-tale signs
of WIMP interactions.
