In Into the Universe with Stephen Hawking, Stephen Hawking discusses three themes surrounding the universe: alien life, time travel, and the future of the universe.
With the help of computer animation, Hawking walks us through these topics and helps us explore what is known, what is theory, and what may be possible. He readily admits that some of this may be hard to grasp, but he does a good job of using analogies and breaking down his explanations into understandable bits.
In the segment Aliens, Hawking looks at the theories surrounding where we came from: either from amino acids forming the right combination for life or from organisms on asteroids that collided with the earth. He then unpacks the possibility of alien life based on water, a chemical, or gases.
In the segment Time Travel, Hawking lays out the characteristics of the three dimensions that we are accustomed to and argues that they likely apply to the fourth dimension as well. And then he talks about what that means for the possibility of time travel. He explains worm holes and then black holes, laying out the possibility of either item being the key to time travel. He walks us through the strange phenomenon of time flowing at different speeds in different places, depending on mass or how close to the speed of light one is traveling.
In the segment Story of Everything, Hawking explains how the universe came into being through the Big Bang Theory. Gravity is the key to both our universe and our existence. Gravity pulled the hydrogen gas from the big bang together until the atoms coalesced, forming helium. Heavier than hydrogen, the helium drifted to the center of the coalesced gas, forming the core. In the weight of the core, other elements formed, elements necessary for life: carbon, oxygen, iron. Since iron doesn’t produce energy, as the core became more and more composed of iron, the star died, collapsing in on itself and then exploding. The explosion sent the elements necessary for life out into the universe.
So it is only by accident, the accident of gravity and an imperfection in the arrangement of the atoms that led to the elements necessary for life being formed. In essence, life is an accident.
If this is the beginning of life, what is the possible end?
Asteroids. Sixty-five million years ago one hit the earth and probably wiped out the dinosaurs. On April 13, 2029, one will pass dangerously close to the earth but will probably not hit it. Probably.
Supernovas. A special type of supernova produces gamma radiation, the most dangerous type of radiation. The blast of gamma radiation from a nearby supernova could destroy life on the earth.
The death of the sun. As the sun begins its downward death spiral, it will become hotter and brighter, which will make the earth uninhabitable, turning it into a giant iron rock. Then the sun will expand to become a red giant that will swallow Mercury and Venus…and likely the already defunct earth.
The Big Crunch Theory. Although the universe is still expanding, billions of years from now, the universe will slowly start to collapse on itself.
The Big Chill Theory. The universe will run out of energy, becoming cold and dark and a black hole.
Stephen Hawking may be a Cambridge scholar holding the same position that Isaac Newton did centuries earlier. He may be on the cutting-edge of the fields of physics and cosmology. But he can explain things in ways that are understandable. He shows that in Into the Universe with Stephen Hawking.