Futurismic

Transhumanist blogger George Dvorsky points to a debate between astrophysicist Brandon Carter and a team of Serbian researchers, the core of which revolves around how long complex (and intelligent) life takes to evolve:

Prior to ‘recent times’, universal mechanisms were in place to continually thwart the evolutionary development of intelligence, namely through gamma-ray bursts, super novae and other forms of nastiness. Occasional catastrophic events have been resetting the “astrobiological clock” of regions of the Galaxy causing biospheres to start over. “Earth may be rare in time, not in space,” they say. They also note that the rate of evolution is intimately connected with a planet’s environment, such as the kind of radiation its star emits.

For further discussion of our place in the universe see the Copernican Principle, which exhorts us to avoid assuming that humanity, Earth, and our place in the universe can be assumed to be unique and special.

Further the notion of punctuated equilibrium to describe evolution is interesting: might it be extended to describe other evolutionary phenomena? Eric Beinhocker’s superb The Origin of Wealth describes both technology and the economy in terms of evolutionary systems, both of which experience a form of punctuated equilibrium.

[image from eek the cat on flickr]

Enrico Fermi asked a question that has troubled those searching for signals from extraterrestrial civilizations ever since: if the universe is teeming with advanced civilizations (as some solutions to the famous Drake equation would indicate), were are they? (From the physics arXiv blog via Improbable Research.)

Reginald Smith of the self-established Bouchet-Franklin Institute in Rochester, New York state, says in this paper, submitted to the International Journal of Astrobiology, that something is missing from the calculations: how far a signal from an advanced civilization can travel before it becomes too faint to hear. Factoring that in, he finds that:

“Assuming the average communicating civilization has a lifetime of 1,000 years, ten times longer than Earth has been broadcasting, and has a signal horizon of 1,000 light-years, you need a minimum of over 300 communicating civilization in the galactic neighborhood to reach a minimum density.”

Which means that even if there are a couple of hundred advanced civilizations in our galaxy, it’s quite likely none of them will ever notice the others…and our efforts at searching for extraterrestrial intelligence may be doomed.

(Image: Reginald Smith.)

[tags]astrobiology,SETI,aliens,space[/tags]