@High Seas,
Quote:really, really, low probability event.
The main factors such as ....
a physical shelter...we have been greatly aided by a moon and Jupiter soaking up a share of debris..
liquid water....we are the only wet planet we know of
right temperature....too hot and the processes occur too quickly, too cold and the processes are too slow....the porridge has to be just right
a second generation star....the materials of life need to be produced in first generation stars. If the universe is 13.75 billion years old, then the first 8 billion can be eliminated as needed for first generation stars to die, leaving the material for life. This makes our star one of the earliest in the second generation series. Intelligent life may evolve after us, but we may be the first.
enough time...most of what we are has evolved in the last half billion years and the surface will fry in a billion more years but it took 4.7 billion years to get this far which was leaving it a bit late. Another cataclysmic event and we might not make the next billion.
Quote:if there are infinitely many parallel universes
The definition of reality is THIS universe so even if they do exist, they dont. Parallel universes is one of the many ways science is trying to out do religion. Using a huge energy machine to measure extremely small pieces of energy is the equivalent of a kilometer size thermometer to measure the temperature of an amoeba. A bad idea to begin with, no wonder it produces strange results.
For completion sake, I should mention there is no possibility of alien life and us ever getting together, even if they are only amoeba. If it is made of matter, it will never approach the speed of light, let alone reach it. We are stuck here, and "they" are stuck there.