Modern observations show that the universe appears to be expanding, and that about 13.7 billion years ago it was much smaller and hotter. As it expanded and cooled, hydrogen and helium condensed out of the initial soup up of high energy particles. Massive clouds of hydrogen compressed by gravity gave birth to and fueled the stars. All of the elements heavier than helium are produced in fusion reactions that power the stars. The heaviest elements that make up the Earth and other rocky planets are remnants of supernova explosions of hot white stars.
Life on Earth is dependent on the debris leftover from one or more of these supernovas that occurred more than 4 billion years ago. Our bodies are about 90% stardust, and 10% hydrogen left over from the origin of the universe. Billions of years of evolution have resulted in biological organs, our brains, that have the ability to comprehend and appreciate their own existence. Our brains control a network of nerves that can animate our bodies, and experience the universe through our senses. At some point in the evolution of life on Earth our universe became self aware via unique arrangement of primordial hydrogen and stardust. (more…)