Is there intelligent life out there or are we alone in the universe?
If it is suggested that humankind is probably the only intelligent life in the universe, some people condemn this as an arrogant thought. But this is not a matter of attitude or emotion; it is a matter of science and probability.On the one hand, it seems impossible that humans can be alone in the universe. A typical galaxy can contain around a billion stars and there are thought to be approaching 200 billion galaxies in the observable universe. On average each star has two or three planets revolving round it, so there must be millions in the ‘goldilocks zone’ where it is not too cold or too hot for liquid water to exist (which is the basis of any life that we can understand).
On the other hand, the existence of humankind on planet Earth revolving round the Sun is the result of a whole series of highly improbable variables. One of these is the ‘jump’ from single cell organisms to multi-cell organisms, something which is sometimes known as ‘the fateful encounter’ that has happened only once in more than 3 billion years of the existence of bacteria. Such an encounter does not guarantee the evolution of intelligent life forms; after all, Earth has experienced five great extinctions when substantial proportions of life on the planet were wiped out. So us being here is quite improbable.
There is actually something called the Drake Equation that attempts to give some sort of guidance as to the probability of intelligent life. It consists of seven key variables. The last of these is the length of time for which intelligent civilisations release detectable signals into space. Humans have only existed for a tiny fraction of the past life of the universe and may not continue to exist for long in the future life of the universe. So, even if other intelligent life has existed, maybe it did not coincide with our existence as a species.
I find the detectable signals variable of the Drake equation the most compelling in terms of deciding whether there is any other intelligent life out there. Any intelligent life must use parts of the electromagnetic spectrum to communicate – as we do with telecommunications, radio, television and the like – and, even if they had no wish to communicate with other intelligent life in the universe, these signals would travel through the universe for ever. Forget flying saucers and the like – how is it that we have never detected any such signals? Even ET phoned home.
On the balance of current evidence, I think that our working assumption has to be that we are alone. If we are the only intelligent life form that exists or has ever existed, we have a tremendous responsibility to preserve humankind and make it as civilised as possible.
November 5th, 2023 at 8:05 pm
Given how damaging to other life on earth “intelligence” has been as well as damaging to our own happiness, it’s quite wise to start to think evolution of intelligent life was a mistake designed or otherwise…… Seems the great planner or chance wisely doesn’t want to make the same mistake again, now that’s true intelligence…. maybe there is life out there just not “intelligent” life …good thing too.. after all meeting other “intelligent” life would probably not be a pleasant encounter going by the example we have set… On the other hand they probably so intelligent so as to be able to stop their technology signals from being detected….
November 5th, 2023 at 8:29 pm
Tom, You seem to be suggesting that “the great planner or chance” has made a mistake but this is to infer that either intended the form of intelligent life that you find so abhorrent. I don’t believe that there was any intention and I don’t believe that humankind is a mistake. We are here simply because of science and we have achieved wondrous things. We have made mistakes but would you rather that there had been no humankind?
November 5th, 2023 at 9:49 pm
“Two possibilities exist: Either we are alone in the Universe or we are not. Both are equally terrifying.”
Arthur C. Clarke
The similarity of surname is pure coincidence …
November 6th, 2023 at 2:06 pm
I think I understand what Arthur C Clarke was saying but I don’t see either option as terrifying.
If we are alone in the universe, there is no need to feel lonely – there are almost 8 billion of us. We might feel a special duty to survive but we should already have that imperative.
If we are not alongein the universe, there is nothing to worry about. Meaningful contact between us is unlikely given the vast distances and any physical interaction looks impossible from all we currently know about cosmology.