If alien civilisations exist, how numerous might they be? and how would they compare to humanity?
In March 2009, NASA launched its Kepler space telescope in an attempt to find other Earth-like planets, and perhaps even alien life.
The Development of Extraterrestrial Life
In recent years, several hundred planets have been found orbiting other stars. Most of these are huge gas giants, similar to the planet Jupiter, and these are unlikely to harbour life.
Many more Earth-like planets are expected to be soon found, thanks to a host of space and land-based research projects.
The mechanisms and probabilities of the development of life are currently unknown. However, given the vast number of stars in the Universe, even if the chance of life developing is extremely small, that would still lead to numerous inhabited planets.
Life on Earth took billions of years to move beyond relative simplicity. Once it did, it took many more hundreds of millions of years for humans to develop. Pre-human animals certainly possessed intelligence, but it took Homo sapiens to develop civilisation, technology, mathematics, and science.
This development has occurred in a cosmic blink of an eye. An analogy used by the world famous scientist Richard Dawkins is to compare the age of life on Earth with the length of an adult arm.
If a nail-file was taken and a single brush of a fingernail was performed, the minute amount of resulting dust would represent all of human history.
In that single brush, the Earth has seen mankind advance from using stone tools to putting men on the moon. Every part of the planet has been mapped using satellites, terrible diseases have been conquered, and global communications have been established.
If humanity can do this in less than 10,000 years, what could extraterrestrials do?
The Development of Extraterrestrial Civilisation
The average intelligence of an extraterrestrial could range from rudimentary problem solving skills to mental capacities a hundred times greater than the greatest minds in human history.
Given that human intelligence evolved to allow the species to cope with task such as hunting, gathering, evading predators, and planning for the future, it is possible that alien intelligence could be roughly similar to humans.
Assuming that it is, and assuming that such creatures establish a civilisation, it is very possible that they would develop science and technology along similar lines to us.
The details would be different, but given that the laws of physics appear to be the same everywhere, their technology would not be radically different to humanities, at least in the short term.
In the longer term, anything is possible. Human civilisation, if it survives its infancy, may develop a level of sophistication undreamt of today.
Extraterrestrial civilisations would be no different. An alien civilisation 10,000 years older than mankind would consider even humanity’s greatest achievements as childlike. 100,000 years old, and such a civilisation would be almost unrecognisable.
It is likely that all disease and illness would have been eradicated, space-travel would be common-place, and the scientific understanding of the Universe virtually perfected.
Given that the Universe is over 13 billion years old, it is possible that the Universe contains civilisations millions or even billions of years old. The achievements of these races would make human science and technology look pathetically basic.
Perhaps one-day such a civilisation will be contacted, or maybe humanity will advance to such an incredible point.
