Sunday, May 09, 2010
Here's one more counterpoint to Stephen Hawking's recent comments about aliens that is worth sharing as, though I don't entirely agree with it, it goes over a few points I mentioned in greater detail. In particular point #5 (seems to be a typo in the title there, but I digress) mentions just how little of the galaxy should know about us by now through radio signals: with a radius of 100 light years our radio signals have now reached about 2000 stars, 10% of which are like our sun...but this only makes up 1/10000000 the volume of the entire galaxy, and even optimistic estimates from the Drake Equation estimate the nearest super-civilization to be at least 1000 light years away. To everyone else Earth would just look like an inhabitable biosphere.
A tiny bit of fear about what is out there is a good thing though, in the same way that preparation against earthquakes and floods and all the rest is motivated from a sense of preservation. Whether aliens know about us is impossible to say right now but asteroids certainly are a possible risk.