There are essentially two arguments for why the Search for Extraterrestrial Intelligence (SETI) may not be a good idea: it is a waste of funds, and it may end up attracting unwanted attention from hostile or exploitative alien civilizations. On balance, as can be quickly shown, the benefits to SETI probably at least equal or outweigh these drawbacks. Nevertheless, in the wake of Stephen Hawking’s televised and much-discussed claim that SETI might endanger humanity, it is worth considering that our currently minimal SETI efforts do have risks and costs as well as potential benefits.
– It Costs Money –
The Cold War Space Race is over. At a time when funds for space exploration and research have dropped to depressing lows, then it may be worth questioning whether SETI is really worth the money. After all, we are not actually sure that there are any intelligent extraterrestrials out there to detect signals from. Moreover, if there are such beings, then absent an extremely large budget with which to buy radio telescopes and supercomputers, we have no way of being at all confident that we will be listening to the right piece of the sky, at the right time, to hear them.
Perhaps most distressing of all, assuming that highly advanced civilizations are out there among the stars, we cannot say for certain that they’re using high-powered radio waves to communicate. If they have discovered some unimagined alternative communications method, then all of the time SETI has booked on the Arecibo Observatory may have been an unfortunate waste of time. Humanity has only been transmitting radio signals into space for about a century (a very short time in a universe whose age is measured in billions of years), and some of the most powerful of those, television carrier waves, are probably already reaching the end of their brief lifespan thanks to the decline in television broadcasting in favor of digital and satellite communications.
On the whole, what this means is that the already unlikely chances of detecting an alien civilization may be even smaller than SETI proponents have long realized. If so, it is somewhat difficult to justify spending large sums of money on SETI on the off-chance that a major discovery might be made, when the alternative is spending the same money on less speculative research programs which will produce definite results, like building more space probes. In fact, this trade-off essentially reflects what is happening today: Only a token amount of money is dedicated to SETI, because advocates find it difficult to convince governments or wealthy private foundations that a larger investment is justifiable.
– Who’s Listening? –
The more serious reason why SETI might not be a good idea, however, is that we have no idea who might be listening to us. If we on Earth have evolved to the point of attempting to detect alien civilizations, in other words, there is at least a fair probability that other civilizations have evolved and might be searching for us. If they do exist, are we sure that they’re the sort of people that we would like to meet?
On the surface of it, this sounds like a rather loopy suggestion – and it is, at the very least, extraordinarily unlikely that an extraterrestrial species is going to visit Earth and announce their presence to us. However, SETI is premised on the equally unlikely chance that we will actually detect alien radio signals. If a very small chance of success is enough to justify SETI, then we must consider also the very small chance of disaster.
This is where famed physicist Stephen Hawking’s comments enter the picture. In early 2010, Hawking claimed on his television documentary that if extraterrestrials visited Earth, we would very likely suffer a fate similar to the indigenous peoples of the Americas: Hopelessly technologically inferior, we would quickly find ourselves subservient to the aliens, or worse.
The concern is a good one – and, in part, inspired James Cameron’s recent blockbuster “Avatar.” In a universe where resources are extremely scarce, advertising that Earth is a planet rich enough to support intelligent life might be tantamount to broadcasting an invitation for more advanced, imperialistic or predatory alien species to seize our resources for themselves. If this happened, there seems a very good chance that they would actually be even less concerned about our well-being than the Spaniards were in Latin America. After all, we would not even be of the same species – and, aside from a few exceptions regarding actually endangered species, humans are generally not particularly worried about whether animals’ rights are affected when we log, mine, dam rivers and alter the environment in many other ways in order to secure valuable natural resources. It’s a very pessimistic position, but one can certainly see the logic in it.
The response, from people who might be termed the idealists in this debate, is that there is probably nothing to worry about. There is a reasonable chance that a species so greedy, aggressive, and short-sighted that they’re reduced to scavenging the galaxy would have destroyed themselves in a nuclear war or catastrophically exhausted their resource base long before they actually achieved the technology for interstellar travel – as, indeed, human beings have seemed poised to do since the 1950s. Moreover, any species which has achieved the intelligence and technological achievement necessary to make interstellar travel possible has very likely advanced to the point where a single planet, its small population of humans, and its depleted and modest supply of mineral resources does not make a particularly attractive target anyway. (Even today, many believe that the Moon and the asteroid belt have far richer supplies of necessary resources for future space travel, if only we could get there cost-effectively.)
Plus, the idealists point out, there’s something which Hawking may not have considered properly: if there are predatory aliens out there who are searching for target planets, then whether we have a SETI program or not, we’re already emitting the radio signals that could help them find us, thanks to broadcast television and our various other methods of radio communication. At least for the time being, we probably lack the technology to make ourselves much more visible than we are. Still, if Hawking is correct, then deliberately broadcasting first contact messages out into space in the hopes that an alien civilization will receive and decode them is a path that is at least foolhardy, and possibly suicidal.
Ultimately, the debate Hawking has started cannot be easily resolved, because we are reduced to guessing about the nature of aliens whom we aren’t even sure exist. If they are as aggressive and imperialistic as we are, and we need our resources, then first contact is going to be an unpleasant experience – and there’s no need to make it happen sooner than it has to. On the other hand, if they have moved beyond those self-interested notions (or simply never had them to begin with), then first contact might be a positive experience. Ultimately, this is a question for philosophy and metaphysics, not just for SETI.