Carl Sagan’s famous quote says “The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of starstuff.” In that famous quote, Sagan makes reference to the whole universe started off with hydrogen and helium, all stars produce helium, and then stars over a certain mass threshold produce carbon, nitrogen, oxygen and lots of heavier elements – which are also the source of the life. The star stuff is inside us – every living thing on Earth.
But, even stars are aren’t powerful enough to create heavy elements like silver, gold, and cesium. Since the 1950s, scientists have wondered: where do most of the elements in the periodic table come from?
Continue reading LIGO detects gravitational waves from neutron star merger
