Dark matter has so far eluded detection. It’s either a very crafty creature (like Bigfoot), or it’s just super-duper hard to pin down.
I woke up with one extra energized brain cell this morning – lucky me – so I decided to go ahead and do some digging on the matter (every pun intended). Why not? Writing about dark matter in the dark seems fitting enough.
Currently there are three ways for physicists to try and detect dark matter: Make it, break it, or wait for it. None of these techniques has worked so far. However, physicists are proposing a new way that appears to be based on a combination of the break it and wait for it methods.
Dark matter particles are thought to annihilate into dark radiation when they collide, therefore we should be able to detect the signals from this radiation.
While still hypothetical at best, based on the standard model of cosmology, the total mass–energy of the known universe contains 4.9% ordinary matter, 26.8% dark matter and 68.3% dark energy. Thus, dark matter is estimated to constitute 84.5% of the total matter in the universe, while dark energy plus dark matter constitute 95.1% of the total mass–energy content of the universe.
Let’s compare this standard model of cosmology to a cup of coffee. I drink mine with one packet of artificial sweetener and a hint of milk (we’ll call this ordinary matter). The coffee grounds are your dark matter, and the water used to brew the coffee is your dark energy. Put them all together and you get the total mass–energy of the known universe. And let me tell you, coffee is pure energy! 😉
Now let’s compare the radiation theory to the brewing process. You have to heat the water and let it flow through the grounds. This process makes the individual grounds of coffee clump together in a way – thus they are closer to each other and you have the “collision” part of the equation. During this process, we begin to smell the sweet aroma of the coffee and see the steam – thus we visually detect signals that the coffee is ready.
Although this is a simplified version, once you start to think about it their proposal seems to make sense. You can find out more about this proposal here – Radiation could be key to finding dark matter.
Image Above: Galaxy cluster Abell 370 with dark matter map. Credit: NASA/ESA/Hubble et al.