Firstly, what is “life” as we commonly define it? The traditional definition is that organisms:
- maintain a state of homeostasis
- they are composed of cells
- undergo metabolism
- can grow and adapt to their environment
- respond to stimuli
This is the current human definition based on our limited understanding from observations on this planet. We associate life with water and carbon-based organic matter, but there is no reason that life could not have some other form of chemical structure such as being based on silicon, ammonia or chlorine.
We believe that consciousness is a special attribute found in more advanced life forms. Rocks and plants are not considered to be conscious.
We know that the universe is really big. Our Milky Way galaxy has about 100 billion stars, and around each of these stars may be a solar system similar to our own containing a number of planets. Our galaxy is only one of about 10 trillion galaxies, each of which may have 100 billion stars, and each of which may have a number of planets, some of which could be similar to planet Earth. So there could be something like 10^25 (that is 10 with 25 zero’s) planets in our known universe. So far there is only one that we know that contains life as we know it – our own planet Earth. It seems likely that other planets could also contain forms of life, but so far we have no idea how many or if life is present there at the same time as life on earth. Life may be very common in the universe, or it may be a very rare phenomenon. We are currently unsure because we haven’t been able to venture far enough off our planet to verify or disprove either theory.
Human beings appear to be the most “intelligent” species on this planet, and there is a tendency to think that we the most intelligent beings that have ever existing anywhere in the universe. There is no proof or contradiction to this, but intuitively it doesn’t seem right (to me, at least) – there must be life elsewhere in the universe and it is quite likely that there will be beings less intelligent than us, and some of these beings will be more intelligent than us.
How life arose on planet Earth is also still the subject of speculation. The predominant scientific theory is that arose spontaneously from a random event. The likelihood of this happening is very low, but the fact that we are here is proof that indeed it did happen! This is not a very satisfactory argument. The likelihood of simple RNA forming by chance, a 300 molecule long protein, is approximately 1 in 10^390, and the chances of that forming in 13 billion years (the current age of the universe) is very small. However, there may be simpler self-replicating processes that precede even the simple RNA building blocks of life that we do not yet understand and these could greatly improve the likelihood of the formation of life. The fact that it has happened leads many to view positively the idea of a God controlling the creation, and if “intelligence” exists as a force or quality within the universe, then this may be true (as taught by the ancient Hindu masters) and would help explain how life appeared despite the improbably low chances.
Recently, the hypothesis that the building blocks of life may have been seeded by early comets (Panspermia) has gained credibility. This theory states that the building blocks for life where created soon after the Big Bang 13.8 billions years ago, and there subsequently distributed through the universe by comets and meteors and cosmic dust particles. This would mean that reasonably similar forms of life are likely to be present across the universe. This theory does not explain how these early building blocks were created in the first place.
One Hundred Monkey Theory
Many scientists still cling to the 100 monkey theorem – that 100 monkeys randomly plonking away on typewriters would eventually produced the complete works of Shakespeare. This won’t ever happen, because the time required for this to occur randomly is many time longer than the age of the universe (let alone the useful life of a typewriter or that of the species of monkeys! Incidentally, somebody did try this experiment with 6 monkeys and it didn’t go so well; the monkeys soon got bored and shit on the keyboard and started throwing the typewriters at each other! ). The fact is that whilst we human beings are intelligent and somewhat self-aware, we don’t yet know everything there is to know.