Everybody (with little exceptions) wonders if extraterrestrial civilizations exist. There are many theories on this topic. Some of them claim we are the only life in the Universe. Others stipulate there are a few other planets with life on them and even provide an estimate how many other civilizations could be out there. A lot of money and much efforts are spent on finding one but without success yet.
I also hoped that an extraterrestrial life was going to be discovered any moment. But recently I looked at the timeline of the Universe (and the dates of life evolution) and became more accepting the idea that we are the only life – the result of amazing coincidence and lucky sequence of events.
The Universe exists 13.5 billion yours. Life has appeared only one-third of this time ago after the Solar system was formed and water provided the birthplace on Earth.
After that, many other lucky coincidences happened that might not happen at all that allowed the life to continue and develop. But even the fact that it took two-thirds of the Universe’s existence to produce life tells me that it is very improbable that somewhere else it has happened. I would be more open to such a possibility if it took only one-millions of the Universe’s existence to generate life.
Imagine you are throwing two six-sided dice 10 times. Could you hope that after the 6th time you get 12 points every time for the next 3 times? Sure, you can hope, but how much would you bet? Not much, probably. Meanwhile, the chance for the life to be born spontaneously is much (much!) less probable.
By the way, this low probability is used by many people as the proof of the intelligent design. But this is a completely different topic.
In any case, I stopped hoping that an extraterrestrial civilization is going to be discovered.
If you are upset by this statement, send me your arguments. I would be happy if proved wrong.
P.S. Here is a very respected opinion of Asaac Isimov that contradicts mine. Oh, well…
Who is stupid?
Kids made laugh of little Johnny by offering him to choose between a nickel and a dime. Little Johnny always took the nickel.
A kind person had a pity on him:
– A dime is worth more than a nickel, even though the nickel’s bigger.
Johnny grinned:
– Well, if I took the dime, they’d stop giving me money.
If we take into account only that region of the Universe where our Solar System is located, then I agree with you 100%. But if we consider many regions in many star systems and many Galactics, where events happen, I think, in parallel, the number of such regions is huge. How big? You as a physicist should know better than I – an engineer.
Your probability of another life form one must multiply by that huge number. Not only that. We must multiply the result by the number of possible life form (different than ours).
That’s the challenge for the scientists – to figure these numbers!
But it will not change the conclusion you have come to (“I stopped hoping that an extraterrestrial civilization is going to be discovered”). Because we exist in our region.
I don’t trust theories that cannot be falsified. What is 13.5 billion of years? Anybody can imagine it? Maybe time itself behaves differently on such stretches than during 1000 years only. Maybe it is non-linear. Maybe it was not zero at the beginning but a singularity instead.
Big Bang theory for me is just a theory that covers most (but not all) experimental facts. New facts will bring new theory. In short, not an explosion, but a “disturbance”? Deep thinking 🙂
And aliens can be very different. Not necessarily a humanoid type. I think I heard viruses were found on an asteroid. Here you go. Another kind of aliens…