The trail to life

In the last chapter we said that the Big Bang and the appearance of the universe from the vacuum were two very striking facts. Now we want to turn to a third, very striking, impression, which emerges from this long history of the universe: the fate of the universe seems quite fantastic. The destiny of the universe seems mischievously entwined with a lot of disconnected events. Some of these took place unimaginably quickly, such as the burst of activity during the first 10-32 second of inflation, or the sudden intervention of a cosmic domain creating havoc in its path. Others seem rather protracted affairs, such as the lethargic progress that followed the first quarter of an hour, and the launching of the universe on a never-ending expansion.

Key events like these arise from microphysical properties, such as the Heisenberg uncertainty relations, and from processes operating on the largest scale, such as the expansion of space as described by Einstein's equations.

Among the decisive events, some had direct action on the course of the universe and, therefore, on our place within it. The eventual disappearance of matter, through proton decay, would have major consequences for the universe and in particular for us: no matter, no humans.