Having been recently confronted with a problem of humility – in terms of being or not being the only intelligent life form in the Universe, I spent a few minutes contemplating the issue, before realizing I own a hopelessly small amount of information on the subject. Several hours of data mining later, my only achievement was to understand precisely how small my amount of information really was. Therefore, I will attempt to synthesise the matter and point out the variables I am missing, in the event someone can be of some scientific assistance.
According to the information we have, the Universe has begun its expansion around 13 billion years ago.
10 billions of years ago, the first Population I stars appeared, along with the probability to have solar systems, thus planets, thus organic life.
Variable 1: is it chemically possible to obtain the level of complexity of carbon based substances with other elements? Is it viable?
The Milky Way took some 3.4 billion years to form.
Variable 2: is it possible for a star with a solar system to evolve unperturbed while being mechanically aggregated in a formation such as a galaxy?
The Sun appeared around 4.6 billions of years ago.
Now, apparently, the life span of a star in the Sun’s class varies greatly, as a function of its size, composition, galactic mechanics and the probability of interaction with other objects. The Sun, for instance, took about 1.5 billion years to cook some life on Earth and should take about another 4.5 billion years to scorch it – if all goes well, that is.
To have life evolve from zero to what it is now, it took Earth about 3.7 billions of years, of which the design and engineering of our species represents only the last 500,000 years or so.
Variable 3: are we lucky? Was this a very fortunate or a very lazy rate of evolution? – because it took us say 3.6 billion years to guess the correct DNA, 300,000 years to make fire, 190.000 to write, another couple of thousand to invent electricity and a year or so to change the LCD-s into LED TVs at half price.
Coming back to galaxy time – astronomically speaking, a intelligent species would have under one billion years to figure out a way of leaving their rock, then about another billion and a half to figure out a way to travel through the galaxy. One should ponder that against the probability of a solar system or star catastrophe.
Variable 4: does physics allow that at all?
Variable 5: can life itself remain regenerative for that long?
The point is that all we have experienced so far is a fulminating race of advancement, despite what we consider today humongous errors in judgement across history. By our own means we can theoretically leave our rock, but we have practically nowhere to go. We travel too slowly to consider candidate destinations in the galaxy. However, this situation has improved so dramatically over the past century that anyone who mentions the word „impossible” is automatically a retrograde.
In conclusion: our competition in the Universe should be within the Population I stars who emerged some 6.5 billion years ago. All things being equal, they have a maximum 2 billion years ahead of us.
Variable 6: What is the statistical age of an intelligent race?
That is perhaps the most important question of all. Without being intelligent, Earth races don’t have a particularly high tendency to survive. They are occasionally recycled through evolution. How about intelligent races? – because humans seem to have got it in their heads that the only things that can put an end to them is bound to put an end to life altogether. So, is it fair to assume that intelligent races are virtually immortal, as far as the Universe goes?