For those of you who don’t know, the Universe consists of only 5% of normal, ordinary matter. But then, what is the rest of the Universe made of?
The most popular theory at the moment is that of dark matter (and dark energy). This is a type matter that neither absorbs nor emits light. It is hypothetical substance and its existence has not been proven… yet. However, there are many experiments set around the world eager to be the first one to find out the truth about this matter (pun?) since it would bring our knowledge of the Universe to a whole other level.
One of these experiments is the LUX Detector in South Dakota, USA. It is set 1500 metres underground, in what used to be a gold mine, to reduce any influence of background particles. It consists of a 370 kg container with liquid xenon in it, and two detectors on top of the container. The experiment works in the following way: when xenon particles interact with other particles (such as the hypothetical dark matter particles) it releases photons and electrons. This can be detected and the difference times these two subatomic particles are produced can be recorded, so the depth of the interaction can be known.
Said interaction between xenon and dark matter is caused by the ability of the former to create a gravitational pull on normal matter. The most probable candidate for thedark matter is a WIMP (Weakly Interactive Massive Particle).
However, after 3 months of searching for this mysterious particle, there have been no relevant results. There have been experiments in the past that have had interesting resulsts which were hopefully going to be confirmed by the LUX, but which were not, unfortunately. The theory of the experiment is not doubted and the scientists there all agree that the machine is working perfectly well. A new theory is that WIMPs might not interact so eagerly with normal matter.
But don’t worry, LUX fans (Luxies?), the experiment is still going to be working in the future, due to its versatility. The advantage of this specific experiment is that it should not only work for detecting WIMPs, but also other particles with a range of masses.
Let’s hope the experiment works as well as it should and maybe someday soon the existence of dark matter will be finally proved, or disproved, to leave space for other theories.