For decades now, the people at SETI (Search for Extraterrestrial Intelligence) have been scouring the skies looking for evidence that suggests the universe is occupied by beings other than humans. Besides a few promising mysterious signals (most famously the “Wow! signal” that was detected in 1977) with unknown origins, the search has largely come up empty handed.
If intelligent beings exist, where are they? Why aren’t we picking up their radio signals? Are they picking up ours? Perhaps they’re out there, but we’re just not looking in the right place? Perhaps we don’t even know what to look for, and we could be looking directly at it without realizing what we’ve found?
A New Proposal?
One proponent of such a theory is Geoff Marcy, the new chairman for SETI at the University of California at Berkeley. Marcy is a seasoned American astronomer who is famous for having discovered over 100 exoplanets (that’s 100 more than me). He thinks we should focus our search for ET around Dyson spheres. In case you need brushing up on your sci-fi, a “Dyson sphere” is a hypothetical massive set of solar panels that would surround a star, collecting a vast amount of the stars energy output. Thus, any intelligent civilization (see: super-intelligent civilization) would be provided with all of the energy it could ever need.
A highly technological civilization would be heavily dependent on energy, just as we are. So a Dyson sphere, or something of a similar construct, seems like the most logical endgame in terms of supplying fuel to a growing population and environmental preservation. Which brings us to another question entirely: if a Dyson sphere encompasses a star to soak up all of its energy output (meaning little to no light escapes), how would we go about finding one? Well, stars give off all sorts of things besides visible light. Heat being one of them. The Hubble Telescope(and the Spitzer Space Telescope, which is excellent at detecting infrared), is equipped with several tools that can capture ultraviolet light, infrared, and x-rays…along with visible light (obviously). If we spotted out a section of the cosmos where a Dyson sphere was in use, we could see a blackbody object that’s radiating in the far infrared around 10 microns in wavelength. The star would be radiating light in a blackbody spectrum that’s captured by the Dyson sphere, and released back out at a distance of 1 AU (the average distance from the Sun to the Earth). The blackbody temperature for the region would be about 100 to 600 Kelvin for a full or partial Dyson sphere.
What Does It All Mean?
Now, detecting an area of our galaxy that has the signature mentioned above isn’t a sure fire sign of a Dyson sphere being used by an alien race, but it would have some interesting implications. The major point being that we need to open our minds a little bit further and take an nontraditional approach in our search for extra terrestrial intelligence. So far, the methods we’ve been usingaren’t providing us with anything. Perhaps we are in dire need of changing the way we envision what an alien intelligence might be? If we ever find them, it isn’t likely that they’ll meet the preconceived notions we have of them. That, may ultimately be our downfall.