Last night I watched Human Universe with Prof. Brian Cox, a great series with stunning visuals and the history of our little species. This particular episode dealt with the Drake Equation, Fermi’s Paradox and Von Newman machines, but sadly came to the conclusion we are more than likely alone in the Milky Way as an intelligent life form. Wow, what arrogance as a species we must have, that our current technology levels and understanding of science means we can make this assumption.
For those not familiar with the paradox, it in its most simplistic rendering is “the universe is old, intelligent life should be everywhere, we can’t see it, and therefore it doesn’t exist“.
The Drake Equation, written by Frank Drake back in 1961 is a formula to work out the chances of active and communicative alien life in the galaxy, based around number of stars, plants, planets with life, planets with intelligent life and planets where the intelligent life hasn’t gone and do something stupid like kill is biosphere with pollution. When originally formulated the Drake Equation put the number of stars with planets in the order of .2 to .5 of stars having planets. With the Keppler Mission and Earth based micro-lensing techniques it is now considered that nearly every star not only has a single, but multiple planets around it. The Drake equation is also based on just planets and not moons around those planets that may support life, such as the Jovian or Saturnian moons in our case.
Next of course is the really tricky part of getting past the Cambrian Explosion(1), to get to multicellular life . This also suffers from anthropic bias as we are only dealing with a study where N=1. Long term missions to Mars and and the Jovian Moons will be required to see whether this is the case or not. Any multicellular organism on Mars, or fish swimming in a Europan ocean will answer that quick smart. But that would make the equation N=3 and for our solar system only.
Yet my major issue with the Fermi Paradox when addressed to the Drake Equation, which science is putting more and more places for life to occur in the galaxy, is the expectation we will be able to spot any intelligence.
Scientists are already looking at analysis of exoplanets (2) to look for tell-tale signs of industrial impact on the planet’s atmosphere. That is, to look at the atmosphere and see if they have screwed it up as much as we have by leaving a pollution finger print. What if for example they were smarter than us and worked out polluting your atmosphere with high levels of CO2 was a dumb idea and didn’t go down that path, or did so, and then cleaned up their act.
Next we are looking in the radio spectrum for their noise. We have been leaking radio since the early 1900’s, but thanks to the inverse square law these weak signals are so diluted by the time they get a few light years out they would be almost impossible to detect (3), well using our technology that is. Apart from a couple of messages when have deliberately sent, we aren’t really broadcasting ourselves. For me a major bone of contention is that radio is the be all and end all of the search. If we were to look for humanity 200 years ago via radio, we couldn’t find ourselves. We wouldn’t find the tell-tale signs of pollution in the atmosphere, and certainly if we sent a radio message to us 200 years ago, we could detect it either.
Perhaps using radio is just a phase we are going to go through and grow out of as we find new ways of communicating, who is to say than in 45 years’ time we don’t work out subspace (thanks Roddenberry) as a way of communicating over interstellar distances, or some sort of Higgs Field Transducer which vibrates messages across the galaxy on the very fabric of space/time itself. Each of these ideas are just as fanciful to us as radio would have been to a person from 1788 when white folk landed in Botany Bay.
So if we say radio and pollution are just a silly phase we are going through and intelligent life isn’t hanging around on that spectrum, we have a few others things to consider.
Firstly, the amount of time intelligent life is around. Taking once again our N=1 study, we can see that life has had a few goes at popping up on our planet. We presume that there were no intelligent dinosaurs for example. We presume we are the smartest things to have evolved on our planet and we assume that it took 4.5billion years a couple of very large rocks and a shit load of luck that our ancestors survived these encounters to evolve to be us.
Ignoring the Ancients as put forward by Stargate (oh how I miss thee), we can say we are the only tool making intelligent species that has arisen on our planet. But with the N=1 problem, that doesn’t mean it doesn’t happen all the time. Dinosaurs weren’t all dumb lumbering reptiles and there were already mammals around at the same time. If that small Chicxulub rock (4) hadn’t taken out the Yucatán Peninsula and most of the habitable planet who is to say that the mammals wouldn’t have evolved brains like we did, just 60 million years earlier.
Given we are basing all our assumptions on intelligent life on a species that is less than 2million years old, and that we only got around to starting to use tools, farm and do art some 50 to 60,000 years ago, and things like radio only 100 years ago, space exploration 60 years it strikes me as horrible arrogant to start saying we are alone in the galaxy.
And for that extra dash of arrogance just add the issue of time and distance. Thanks a lot Einstein for making the speed of light the fastest thing, which means everything we look at in deep space is in the past. If we look at a planet 50 light years away, that is 50 years ago. Look at planet, 200 light years away, that is 200 years ago, before we even worked out radio existed. Then we need to add parallel evolution to the equation. That is we need to find a species using our technology, in the past which is our present to detect them.
Of course given the timescales involved with our galaxy it is possible for the whole galaxy to have been populated with Von Neumann probes, so proponents of the Fermi Paradox also argue where are these probes. Two things immediately come to mind. One, they are everywhere, but if you can create a self-replicating robot to explore the whole galaxy in under 50 million years, why not make it invisible. Two, why create it in the first place, for what purpose. And three ( yes I know I said two ) what if your evolution as a species overtook the need for such a project and you shut them down after creating them as they are no longer required.
These are just a few issues that I have with saying we are alone in our galaxy. I haven’t even started with the questions about why some alien would want to talk with us, when was the last time you thought about trying to communicate with an ant. Or what happens beyond homo sapiens to us as a species, why intelligent life has to be carbon based and bipedal and faster than light travel. When people in 1980 couldn’t have dreamed the impact the internet would have on society, what amazing technology will come in the next 100 years alone.
And this is why I get cranky about this anthropocentric view of science and the history of the universe.