As our view of the universe deepens and we become aware of more and more solar systems that could harbor some form of life, it seems more likely that one day earthlings will discover “life” — or life will discover us. I wonder what conditions would be required for the former, and what forms that life might take. If life is to discover us, or has already — I’m not ready to speculate on that yet. Hold that thought.
Astronomers have established that there may be between 11 and 40 billion solar systems with life-sustainable planets. I take this to mean general conditions — planets with a reasonable temperature, perhaps the possibility of an atmosphere — though I’m not really sure what constitutes “life-sustainable” in their studies. However, life takes many forms here on earth, and I recall reading that scientists have discovered bacteria living in volcanoes and also deep in the earth and in icy conditions on polar ice caps.
The forms of life are myriad and it seems for life to flourish there must be, in addition to good weather, food and some place to stretch out and live.
Do we take it that life also — to be life — requires some way to reproduce? I think so. We have many ways here on earth. So already for life to be “life” it has to have a certain complexity, adaptability, and self-interest — or whatever it is that causes living things to convert resources, e.g. food, into energy.
Thinking of the forms of life, bacteria, virus, slime molds, insects, plants, animals, others — roughly 9 billion — a key ability they have is to be able to adapt to the environment — or else perish as a species. This suggests that an important quality of life we know it is the genetic structure that changes, because of the environment, because of chance combinations of DNA during reproduction, and because of random changes in the structure.
This raises the question: how likely is it that these key component structures (DNA and RNA) would be found elsewhere? It seems to be a very complex and well-developed, chemically-dependent system. I can’t envision how even over billions of years something like this DNA and RNA could develop, because it seems that for a small building block, such as these, to be optimized, there has to be some feedback from the larger organisms they help create. By “feedback”, I mean there would have to be something on a larger scale than these viruses and molecules that was causing them to be constructed in the first place. E.g. God or life elsewhere that already exists.
DNA is no Lego block. It has code and it has an elegant scheme and set of rules for combining with other DNA to create new organisms. Although, I see this disturbing piece of software. I guess it is possible to tinker with and clone life. But the original engineering work can’t have just been chance. Perhaps I already answered the question, and “life” is just an experiment of some super intelligence. Or God.