(January 26, 2017 at 12:15 am)pool the great Wrote: Nah I don't think aliens exist. We already have older planets than earth in our very own solar system. These planets already have had huge amounts of different gasses and chemicals and reactions for more years than earth. Yet, we only find life on earth.
Life is supposed to modify itself to survive in a given environment so the argument that the environmental conditions are severe in other planets falls apart, besides, severe environmental conditions relative to what?
What we see today is over 4.5 billion years of some chemical reactions just happening to take place in the right order, in the right place, under the right circumstances. So 4.5 BILLION years of just seemingly random events taking place in just the right way to give us what we see today. Can you imagine another planet undergoing the EXACT same kind of events that took place on earth down to a T? It's just awfully unlikely even taking into consideration the size of our universe.
I mean, if you have an infinite number of monkeys typing on an infinite number of typewriters you'll eventually get a Shakespeare. Maybe the Shakespeare is us?
There are plenty of places in the solar system that life could exist but we haven't yet visited to check.
You can't assume that life will survive in all conditions. It can only modify itself within a certain range given enough time. So there could have been life on Mars which died out.
It also depends upon how you define life. We're defining it by comparing it to one single sample (i.e. what we find on Earth). The single defining characteristic of life is that it has a metabolism, not that it's intelligent or has two arms and legs.