Is there other intelligent life out there or are we the 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 importable 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 9th, 2014 at 3:23 pm
Interesting thoughts Roger. Also interesting is how this scientifically thought out concept is so similar to that of many believers (myself included) of the existence of a divine power or being.
Don’t get me wrong. I can truly appreciate the logical thought process utilized to come to this conclusion, as I consider myself a scientist, but whether we are “alone” or not, while interesting, is not the point for me. I agree that we do have a tremendous responsibility for preservation, but not simply because we may be alone.
If we ceased to exist, would the universe care or take any note? Would it have any notable impact? What is the purpose for continued existence? If you believe, as I do, that there is something far greater than us that designed this world, then that gives me more purpose to strive to improve it.
November 11th, 2014 at 7:47 am
Given how life is so easy to start in all the most impossible conditions and how many stars there are, it is inconceivable that we are alone. There at least 40 times more stars than there are sand grains on the whole of the earth.
We currently believe we must communicate by electromagnetic radiation but earlier earth civilisations didn’t even invent the wheel ie the Incas. So let’s wait and see. It’s early days!