The Big Bang to Now: All of Time in Six Chunks is about the almost 67 billion years we think our universe has been in existence in its present form. That is, with the dimensions of time and space and the laws of physics as we know them.
Looking at the past is an astonishing and mind-boggling experience still full of unanswered questions and continuously disconcerting discoveries. But what about the future? what about the next 67 billion years which some scientists think our universe has to run? What, even about the next 5 billion years on Earth before our sun burns out and life as we know it will disappear?
Of course, none of us can predict the future with certainty. The following, though, are a few possibilities based on what has happened in the past.
First of all, the universe that began with the Big Bang, was filled with unimaginably small particles. Gradually they began to coalesce into simple atoms, and after millions of years in the heat of the stars, more complex atoms and molecules formed. They in turn have become increasingly organized into all the complex forms of matter we know.
Finally, life itself emerged. Life here on Earth, at least, began as simple microbes close to four billion years ago and for perhaps two billion years, these bacteria developed and complexified. But as they became more organized and colonized Earth, they also changed the very fabric of Earth itself. Early bacteria excreted oxygen as a by-product in the same way we exhale carbon-dioxide. Molecule by molecule, their oxygen changed the entire atmosphere surrounding Earth. The early bacteria themselves could not survive in this pool of what today we might call their own pollution, and two and a half billion years ago their reign over the Earth collapsed. Today they survive only in those areas where there is little or no oxygen.
This was the first great extinction event we know about on this planet. It is the pattern of millions of extinction events that continue to take place to this day. The environment changes, sometimes as a result of galactic gyrations, sometimes caused by changes in weather patterns and tectonic shifts, sometimes, as in the case of the early bacteria, as a result of the behavior of the organism itself.
But life has not ended with any of the at least mass extinctions Earth has witnessed. In fact, brutal as it seems, new life, more highly organized, more complex life seems to emerge from the apparent ruins.
Will this happen again? Will the very success of the human species spell our downfall? will we change the environment so drastically that we can no longer thrive here? And if we do, then what?
Perhaps we will have managed to set up life on another planet, even in another solar system, eventually in another galaxy. Perhaps the human species will be replaced altogether by other life forms more suited to the new environment. If so, will that new life form be more intelligent than we? will it be less prone than we are to attacking and destroying members of its own species?
We don’t know. But we can see that the Universe is an ongoing process, and that life itself, even in the face of what seem to be the worst odds and destructive forces, is incredibly dynamic and inventive.