“Ordinary matter is what we are all made of. It has gravity and interacts with light. Dark matter is a mysterious substance that has gravity but does not interact with light in any known way. Dark energy is a mysterious… — Neil deGrasse Tyson Copy Share Image
“Even today, more than eighty years after Oort's bold guess, we still don't have a clue what this dark matter is made of. We know it exists. We know where it is. We have maps of its presence within and… — Christophe Galfard Copy Share Image
