100 Years Ago, Cecilia Payne Discovered What the Stars Are Made Of
For centuries, even after we knew the Sun was a star like any other, we still didn’t know what it was made of. Cecilia Payne changed that. All of that changed in dramatic fashion back in 1925, when scientist Cecilia Payne wrote what was perhaps the most brilliant PhD dissertation in the history of astronomy. Celebrate the hundredth anniversary of this achievement today.