COLD, DARK, MATTER: IS IT COLD, IS DARK AND IS IT MATTER?

Dr Julian Onions – Nottingham University

– 8th October 2021

In his usual humorous style, Julian went through the maths of why we know something we call “Dark
Matter” exists. If it didn’t stars and the like would be flying off into the universe and nothing would be
as we know it.
Julian went through all the things it could be e.g. is it something to do with gravity? Yet still, we are
no nearer knowing what it is. Many things have been put forward to account for it. Axions and
Neutalinos for example and he explained what these were and why they were being considered.
He showed us how gravitational lensing was used to detect the smallest clumps of CDM.
So we don’t know what it is, can’t see it, yet we can detect it!