The Milky Way is old enough that a slightly more advanced civilization than us could conceivably have colonized the galaxy several times over by now. Known as the Fermi Paradox, the absence of extraterrestrial observations is often taken to imply either the rarity of life or the impossibility of interstellar travel.
In a paper published in the February issue of the Journal of the British Interplanetary Society titled “The Sustainability Solution to the Fermi Paradox“, we challenge this conclusion with the possibility that exponential growth is an unsustainable development. That is, even if an extraterrestrial civilization has colonized the galaxy, it would have done so through rapid unsustainable growth and collapsed upon reaching a physical resource limit. Not enough time has yet passed for a sustainable growth civilization to colonize the galaxy, so there is still promise in the search for extraterrestrial life. Furthermore, though the absence of extraterrestrial civilization does not imply the unsustainability of exponential growth, it does increase the probability that humanity should transition to sustainable development in order to prevent its collapse. A more detailed writeup is available on the Lifeboat Foundation blog.
In other news, NASA’s Kepler Mission successfully launched yesterday evening! Over the next three years, Kepler will observe 100,000 stars in a patch of the Milky Way in search of Earth sized planets. This is the first mission with the capability of detecting Earth at a distance, so with any luck we’ll soon have a better idea of just how common small rocky planets are in the galaxy.