Prehistory
ca. 4000 BCE
 
01 Out of Primal Chaos
 
The prehistory 15–4.5 billion years ago
 
If time travel is possible, where are the tourists from the future?
 
The English physicist Stephen Hawking (1942– ) has been confined to a wheelchair since the age of twenty as a result of a motor neuron disease related to amyotrophic lateral sclerosis, which left him with a paralysed body; at forty-three he contracted pneumonia and had to have a tracheotomy, which removed his ability to speak altogether. However, he never lost heart but spared no efforts in pursuing his research and in the end became the most distinguished theoretical physicist in the contemporary world. His renowned work, A Brief History of Time: from the Big Bang to Black Holes, published in 1988, established him as the highest authority on cosmology.
 
According to the findings of Hawking and other scientists, from the outer space, originally in the state of a vacuum, appeared at an unknown time a gravitational singularity in what is called “the cosmic egg”. (Hawking thinks that within the limits of the space-time in which the singularity exists, all scientific laws and predictability cease to be effective.) This singularity exploded about 15 billion years ago with a Big Bang and formed the universe.
 
The universe expanded rapidly, largely because of the presence of “dark energy”, after the explosion, occupying a space from zero to immensity, its diameter spanning a light year. The matter produced by the explosion gradually cooled down to form nebulae, which in time evolved into the galaxies.
 
There are numerous nebulae and galaxies in the universe. One of the galaxies is called the Milky Way. It came into existence 10 billion years ago. Within the Milky Way are numerous stars and planets. The former are still in a state of combustion, giving out light and heat while the latter have cooled down and give out neither light nor heat.