View full lesson: http://ed.ted.com/lessons/the-law-of-conservation-of-mass-todd-ramsey Everything in our universe has mass — from the smallest atom to the largest star. But the amount of mass has remained constant throughout existence even during the birth and death of stars, planets and you. How can the universe grow while maintaining its mass? Todd Ramsey answers that question by unravelling the law of conservation of mass. Lesson by Todd Ramsey, animation by Vegso/Banyai.