The Large Underground Xenon (LUX) is a massive machine built in 2012 to serve exactly one purpose: to find Dark Matter. It was a pinnacle of scientific achievement, one of the most exact and sensitive tools ever created. It was created to be the most sensitive detection machine on the planet, and then turned out to be over four times as sensitive as it was designed to be. Everything was looking good for the LZ Dark Matter Experiment

But after four years of searching with the most sensitive sensors that mankind can create, the team found exactly nothing.

Not a single ping on LUX’s ultra-exact sensors, not a single trace of Dark Matter.

Dark Matter is mysterious. It makes up more than a quarter of all of the mass and energy in the universe- more than ordinary matter, which only makes up about 5% of the detectable universe. And if you consider Dark Matter and Dark Energy to be two variations of the same thing, as some scientists do, then it makes up over 90% of the stuff in the universe.

But despite it being literally everywhere, as far as anyone can tell, nobody has ever actually been able to see it. Or touch it. Or collect it. Or even really, observe it moving, or doing anything. The only way we can detect it is because it still has gravity, and we can observe other astronomical objects, planets and asteroids and stars, being affected by this gravity.

That’s why it’s called Dark Matter. We know it’s there, we know it has mass (and is therefore matter), but it doesn’t reflect or bend or interact in any way with any kind of energy. Not light, not radio waves, not radiation, not anything. Electromagnetic energy seems to pass through it as though nothing is there at all.

This fact has frustrated scientists for decades as they desperately try to figure out just what all that invisible mass out in the universe is, what it does, and where it comes from. Nobody has been able to provide an acceptable answer yet, mostly because it’s almost impossible to observe Dark Matter. How can you measure and observe something scientifically if there’s almost no way to detect it’s even there?

One prevalent theory is that Dark Matter is made out of hypothetical particles, so small and weak that they pass through everything undetected, and may be passing through all of us every single second without anyone noticing. This was a promising theory, and it was what the LUX experiment was based on.

The idea was to create the most sensitive machinery on the planet, which would be able to detect if these hypothetical particles (called WIMPs) really are whizzing around the earth, undetected.

But then LUX found absolutely nothing, and scientists are back to square one.

With the WIMP theory unsubstantiated after four years of searching, astronomers and physicists are sent back to the drawing board, to look at any and all alternative theories. In truth, we know so little about Dark Matter that it could be almost anything.

Some suggest that it’s just a property of empty space, that space itself is warped and bent, creating empty gravity wells which create the illusion of invisible matter. Some suggest that Dark Matter is temporary quantum particles, which constantly form and then disappear without a trace. One theory even suggests that it’s simply evidence that the current Theory of Gravity is incorrect, and that we need to throw out everything we know about basic physics and start over.

My personal theory is that it may very well be space vampires.

Whatever Dark Matter is, scientists continue to search in their endless quest to satisfy mankind’s thirst for knowledge and understanding of the universe around us. Dark Matter could be explained tomorrow, or in a

couple centuries, or it might remain unknowable for all eternity. But scientists will keep looking, searching, hoping for any sort of clue to these mysteries of the universe.