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]
I myself find Nick Bostroms thoughts on the existence
of extraterrestrial life far more convincing than calculatoins on
radio waves propagations. As futurologists we can now imagine building
selfreplicating machines which propagate into space. The fact that we do
not see aliens is due to their non-existence. That is what Nick hopes and I
can follow his logic. Any civilization which survives the technological
singularity will propaget into space with force and will populate it for good.
If you were an advanced civilization and you encountered a heavily polluted planet, torn by continual war and genocidal violence, in which millions of individuals die due to lack of basic needs, and which is already sending weapons into space, would you make contact?
We are in quarantine and rightly so, in my opinion.
Fully agreed with Mackay’s comment. In fact, I wrote and published a sci-fi novel based on the notion that advanced aliens are out there in huge numbers and purposely keeping us oblivious of their existence due to this very reason. I use the concept of dark matter, one of the biggest cosmological mysteries facing scientists to this day, as a possible mechanism the aliens use to hide from us. Details are on my website at http://www.swahmed.com.
The longer I live, the more convinced am I that beings from other planets use the
Earth as a lunatic asylum.
George Bernard Shaw (1856–1950)