Interdisciplinarity in science can be wonderful: combining expertise across disciplines leads to new insights and progress because it’s only when people from those disciplines communicate about a particular problem that progress is made, and that happens much more rarely than communications among members of a single discipline.
It’s important, though, when working across disciplines to actually engage experts in those other fields. There’s a particular kind of arrogance, common among physicists, that a very good scientist can wander into another discipline, learn about it by reading some papers, and start making important contributions right away. xkcd nailed it:
And my favorite takedown of the type is from SMBC (go read it!)
There’s a new paper about the dangers of SETI out by Kenneth W. Wisian and John W. Traphagan in Space Policy, described here on Centauri Dreams. In it, they describe the worldwide “arms” race, similar to the one in the film Arrival, to communicate with ETIs once contact is established. They say this is an unappreciated aspect of SETI and that SETI facilities should take precautions similar to those at nuclear power plants. Specifically, they write:
In the vigorous academic debate over the risks of the Search for ExtraTerrestrial Intelligence (SETI) and active Messaging ExtraTerrestrial Intelligence (ETI) (METI), a significant factor has been largely over- looked. Specifically, the risk of merely detecting an alien signal from passive SETI activity is usually considered to be negligible. The history of international relations viewed through the lens of the realpolitik tradition of realist political thought suggests, however, that there is a measurable risk of conflict over the perceived benefit of monopoly access to ETI communication channels. This possibility needs to be considered when analyzing the potential risks and benefits of contact with ETI.
I have major issues with their “realpolitik” analysis, but I’m not an expert in global politics, international affairs, or risk aversion so I’m not going to critique that part here. Instead, I’ll stick to my expertise and point out that the article would be much stronger if the authors had consulted some SETI experts, because it is based on some very dubious assumptions about the nature of contact.
The authors seems to think it is clear that once a signal is identified:
- Only around “a dozen” facilities in the world will be able to receive the signal, and that states will be able to somehow restrict this capability from other states. The authors think this covers both laser and radio.
- That it will be possible to send a signal to the ETI transmitter, and that this capability will have perceived advantages to states.
While there are some contact scenarios where these assumptions are valid, they are rather narrow.
First, modern radio telescopes are large and expensive because they are general purpose instruments. They can often point in any direction, and have a suite of specialized instrumentation designed to operate over a huge range of frequencies.
But once a signal is discovered, the requirements to pick it up shrink dramatically. Only a single receiver is required, and its bandwidth need be no wider than the signal itself. The telescope need only point at the parts of the sky where the signal comes from, so it need only have a single drive motor. And the size of the dish need not be enormous, unless the signal just happens to be of a strength that large telescopes can decode it but small ones cannot, which is possible but a priori unlikely.
Indeed, there are an enormous number of radio dishes designed to communicate with Earth satellites that could easily be repurposed for such an effort, and can even be combined to achieve sensitivities similar to a single very large telescope, if signal strength is an issue. And there is no shortage of radio engineers and communications experts around the world that can solve the problem quickly and easily. The scale of such a project is probably of order tens of thousands to millions of dollars, depending on the strength and kind of signal involved. The number of actors that could do this worldwide is huge. Also, such efforts would be indistinguishable from normal radio astronomy or satellite communications, so very hard to curtail without ending those industries.
The situation is similar for a laser signal: if it is a laser “flash” then the difficulty is primarily in very fast detectors that can pick it up. Here, the technology is not as mature, and if the flashes are *extremely* fast it is possible that the necessary technology could be controlled but, again, this assumes a very particular kind of laser signal. And, again, there are an enormous number of optical telescopes which will have similar sensitivity to optical flashes as existing optical SETI experiments (which, again, are only expensive because they search a huge fraction of the sky for signals of unknown duration).
Finally, there is the issue of two-way communication: unless the signal is coming from within the solar system or the very closest stars, the “ping time” back and forth is at least a decade, and likely much longer. There is no “conversation” in this case: the first response to our communications would be ten years down the line! So the real dangers are transmitters within the solar system or signals that contain useful information without the need for us to send signals.
In summary, the concerns expressed in this article apply to a narrow range of contact scenarios in which the signal is, somehow, only accessible to those with highly specialized equipment or from a transmitter within the solar system. The first seems highly unlikely; I do not know to evaluate the second, but note that such signals are not searched for routinely in the radio, anyway.
I’d be happy to engage with experts in space law on a paper on the topic, if I know any?