If you want to make an apple pie from scratch, Carl Sagan famously argued, you must first invent the universe, and for that, you're going to need stuff. But where does the matter that make up the cosmos come from? How is it created? If all matter is composed of three tiny particles (protons, neutrons and electrons), how do we explain the diversity of matter all around us?
In this installment of the widely celebrated documentary series Cosmos, Carl Sagan explores the origin of the chemical elements, how these relate to the birth, growth and death of stars, and even a little general relativity for good measure.
For more on the nature and origin of the elements of the periodic table, check out Jim Al-Khalili's wonderful documentary series Atoms (parts 1, 2 and 3), or his history of chemistry (parts 1, 2 and 3).