This Is The Real Reason We Haven’t Directly Detected Dark Matter
Finding the particle we assume is responsible for dark matter has always been a guessing game. We guessed wrong.
You can’t get mad at a team for trying the improbable, hoping that nature cooperates. Some of the most famous discoveries of all time have come about thanks to nothing more than mere serendipity, and so if we can test something at low-cost with an insanely high reward, we tend to go for it. Believe it or not, that’s the mindset that’s driving the direct searches for dark matter.
In order to understand how to find dark matter, however, you have to first understand what we know so far, and what the evidence points to as far as direct detection goes. We haven’t found it yet, but that’s okay. Not finding dark matter in an experiment is not evidence that dark matter doesn’t exist. The indirect evidence all shows that it’s real. The question before us is how to demonstrate its reality, hopefully by finding the particle responsible for it directly.
Let’s begin with a basic recap of dark matter: the idea, the motivation, the observations, the theory and then we’ll talk about the hunt.
The idea. You know the basics: there are all the protons, neutrons and electrons that make up our bodies, our planet and all the matter we’re familiar with, as well as some photons (light, radiation, etc.) thrown in there for good measure. Protons and neutrons can be broken up into even more fundamental particles — the quarks and gluons — and along with the other Standard Model particles, make up all the known matter in the Universe.
The big idea of dark matter is that there’s something other than these known particles contributing in a significant way to the total amounts of matter in the Universe. Why would we think such a thing?