What Science Can and Can’t Tell Us About our Future
Astronomy has reached the point of being able to state conclusively that the known universe contains a greater number of stars than the number of grains of sand on all the Earth’s beaches and in all of its deserts.
The age of the universe has been definitively set at 13.7 billion years ago. The age of the Earth is around 4.5 billion years. Life first formed about half a billion years later and the human species is about 3 million years old. Agriculture began about 10,000 years ago. The human population size exploded from about 1 billion to just over 7 billion in a little over two hundred years. That rapid expansion coincided with the industrial revolution and the rapid exploitation of cheap, high energy density, fossil fuel resources.
Astronomy has discovered planets circling other stars and has even reached the point where it can estimate their sizes and distances from their mother stars.
It is logical to conclude that planets circling stars must be a very common occurrence around the vast universe. Based on knowledge of our solar system, planets too close to the star are too hot to support life and those too far away are very cold and receive substantially less radiation from their star, so probably cannot support more than the most primitive life forms, if any at all. There is a “sweet spot” at just the right distance, a habitable zone around all stars, where planets of just the right mineral composition can develop atmospheres and life can form.
So it is also very logical to conclude that the universe very likely has a large number of planets currently supporting life and many more that might have supported life in the past, or on which life might still begin in the future.
What we do not know are the histories of life occurrences around our galaxy and in the greater universe beyond. All we have to go on is our own singular case. From our own history, it is abundantly clear that once useful energy resources have been discovered and exploited (whether on or inside the planet or coming from the planet’s star), it is likely that the mass of living organisms on a planet will grow to a saturation point beyond which either the energy source needed to sustain further growth reaches its limit or the waste products and other adverse consequences of the growing mass of living matter will begin to extinguish further growth or send it into a decline toward elimination.
Whatever life forms might have evolved sufficient intelligence to invent technology, it is an interesting question whether that intelligence evolves fast enough for the newly intelligent species to create sufficient self-regulating abilities to halt the growth of living matter before it passes a point of no return, resulting in extinction of the top species on the planet, or possibly a significant reduction of the total living mass to the point where its continuance can be sustained by the existing resources indefinitely.
It seems likely that the universe is filled with a wide range of such life histories and possibly even a large number of life forms that have achieved indefinite sustainability. Wouldn’t it be interesting to communicate with some of these? To learn their histories and see how some might have been able to achieve sustainability? Once a sustainable condition is achieved, does the intelligent species develop more intelligence and insight into the process? What might we be able to learn from it?
Additional reading at The Ecyclopedia of Earth: Human Population History