Why Life On Mars May Foretell Our Doom 431
Hugh Pickens writes "Nick Bostrom has an interesting interpretation on why the failure of the Search for Extra-Terrestrial Intelligence (SETI) for the past half-century is good news and why the discovery of life on Mars could foretell our doom. Bostrom postulates a 'Great Filter,' which can be thought of as a probability barrier and consists of one or more evolutionary transitions or steps that must be traversed at great odds in order for an Earth-like planet to produce a civilization capable of exploring distant solar systems."
Fermi Paradox (Score:4, Informative)
http://en.wikipedia.org/wiki/Fermi_paradox [wikipedia.org]
The Fermi paradox is the apparent contradiction between high estimates of the probability of the existence of extraterrestrial civilizations and the lack of evidence for, or contact with, such civilizations.
Re:Fermi Paradox (Score:3, Informative)
The universe is estimated to be at least 93 billion light years across.
Assuming that special relativity* is mostly correct, if a civilization evolves at the opposite end of the universe, it will take us at least 93 billion years to find out.
*Special relativity: Nothing travels faster than light in a vacuum. No exceptions.
As a point of comparison, the Earth is about 3.9 billion years old, with the oldest meteorites in the solar system being 4.6 billion years old. Within 3.5 billion years from now, the sun will have grown hot enough to give Earth surface conditions similar to Venus, rendering the planet uninhabitable.
By the time the distant reaches of the universe are able to visually observe the very existence of earth, we'll have been obliterated billions of years earlier by the expansion of the sun.
The reverse is equally true. By the time we receive a signal or visual evidence of a distant civilization, it's not unlikely that they'll have died out or moved elsewhere billions of years prior.
Depending upon which theories you subscribe to, all matter will have decayed within 10^40 years. Although this is a very long time, it's fairly probable that many civilizations will evolve, and not discover each other in spite of attempts to do so.
To discover/be discovered, you've got to be in exactly right place at exactly the right time. Considering just how %*$#ing big the universe is, the odds of this actually occurring are slim-to-none.
The Fermi paradox is interesting to consider, although there are far too many exceptions or alternative explanations to take it seriously.
Re:Ignores possibility of the Singularity (Score:4, Informative)
That's unpossible (Score:3, Informative)
What if most evolve beyond physical forms?
There is no such thing as "beyond physical." Everything we know of has a basis in physical reality. Even ideas. Unless you're positing some kind of transcendental disembodied magic, everything has a physical existence.