This topic is a bit more esoteric (just a little?) than I usually delve in to here, but it was the best reading of the day for me yesterday. I just couldn't finish it until last night.
The recent discovery of another planet in our galaxy that might be able to sustain life. It is the first planet almost the same size as earth that is also located in the "habitable zone" or the area of a solar system most able to sustain life as we know it.
Here is the ArsTechnica article on the subject:
http://arstechnica.com/science/2014/04/habitable-exoplanets-are-bad-news-for-humanity/
Here is a snippet from that piece:
What did not make the news, however, is that this discovery also slightly increases how much credence we give to the possibility of our own near-term extinction. This is because of a concept known as the Great Filter.
The Great Filter is an argument that attempts to resolve the Fermi Paradox: why have we not found aliens (or why have they not found us), despite the existence of hundreds of billions of exosolar systems in our galactic neighborhood in which life might evolve? As the namesake physicist Enrico Fermi noted, it seems rather extraordinary that not a single extraterrestrial signal or engineering project has been detected (UFO conspiracy theorists notwithstanding).
This apparent absence of thriving extraterrestrial civilizations suggests that at least one of the steps from humble planet to interstellar civilization is exceedingly unlikely. The absence could be because intelligent life is extremely rare, or because intelligent life has a tendency to go extinct. This bottleneck for the emergence of alien civilizations from any one of those billions of planets is referred to as the Great Filter.
The question of the Great Filter was very interesting to me so I delved deeper in to the links provided. Click on 'Great Filter' above. Here is a snippet from that piece:
Consider our best-guess evolutionary path to an explosion which leads to visible colonization of most of the visible universe:
- The right star system (including organics)
- Reproductive something (e.g. RNA)
- Simple (prokaryotic) single-cell life
- Complex (archaeatic & eukaryotic) single-cell life
- Sexual reproduction
- Multi-cell life
- Tool-using animals with big brains
- Where we are now
- Colonization explosion
(This list of steps is not intended to be complete.) The Great Silence implies that one or more of these steps are very improbable; there is a "Great Filter" along the path between simple dead stuff and explosive life. The vast vast majority of stuff that starts along this path never makes it. In fact, so far nothing among the billion trillion stars in our whole past universe has made it all the way along this path. (There may of course be such explosions outside our past light cone [Wesson 90].)
The fact that our universe seems basically dead suggests that it is very very hard for advanced explosive lasting life to arise. And if there are other radically different paths to expanding lasting life [Shapiro & Feinberg 82], that only makes the problem worse, by implying that the filter along our path must be even larger.
Very interesting reading. I hope you enjoy it as well.
Happy Reading,
J.W. Gant
