For thousands of years, we have thought we knew what the universe – and everything in it – was made of: normal matter, the kind that make up the elements of the periodic table.
Only about 5% of the universe consists of ordinary matter such as protons and electrons, with the rest being filled with mysterious substances known as dark matter and dark energy.
Did dark matter kill the dinosaurs? Recent work by Harvard physicists may have us reevaluating the mysterious substance of dark matter, and how the dinosaurs became extinct.