Hi Reddit! I’m Dr Sarah Malik, a dark matter researcher at Imperial College London in the United Kingdom. In October 2015 I was awarded a grant from the Royal Society to carry out research on producing and detecting dark matter using the Large Hadron Collider (LHC) at CERN. I find it fascinating that more than 80% of matter in the Universe is invisible to us, it doesn’t emit or reflect radiation. This is what we call “dark matter”. We know it exists because it exerts a gravitational force on ordinary matter, playing a critical role in holding together galaxies and shaping the Universe as a whole. There’s reason to believe that it comprises particles that have mass, are electrically neutral and don’t decay; beyond that, we have little understanding of dark matter. How many types of dark matter particles are there? What types of forces do they exert on each other and on the ordinary matter particles? My current research aims to address these very questions. Discovering what 80% of matter in the Universe is made of will play a significant role in defining the future direction of particle physics and cosmology and mark an extraordinary development in our understanding of the world around us. I will be back at 2pm ET to answer you questions, ask me anything! Proof: https://royalsociety.org/people/sarah-malik-7571/ http://lpc.fnal.gov/fellows/Sarah_Alam_Malik.shtml To learn more about me and my research, follow me on Twitter (@SarahAlamMalik https://twitter.com/SarahAlamMalik). You can also see me talk about dark matter at the 2015 Blackett Colloquium (https://youtu.be/BHa65maMIFk), and on the Guardian ‘Big Unknowns’ podcast (from 16:36) (https://www.theguardian.com/science/audio/2016/nov/22/big-unknowns-what-is-dark-matter-science-weekly-podcast). Update Happy Dark Matter Day everyone! I’ll be live for the next hour or so answering as many of your excellent questions as I can. Update That’s me signing off now. Thanks so much for your questions and contributions. I’ll be checking back in from time to time, so feel free to keep the conversation going. Happy Dark Matter Day!