There are many controversies in science, especially where science and the public good overlap. Environmental concerns, energy, and fights over what should and should not be included in publicly funded science classes just to name a few. One of the more obscure debates that’s been simmering for decades concerns the Search for Extraterrestrial Life or SETI. For the most part, SETI has been a program of passive listening. Radio dishes pointing patiently at the sky straining for some sign of alien radio traffic. But there are those who argue we should be more proactive about it and beam out powerful interstellar radio messages intended for alien consumption.
For those wanting to understand the back-story, David Grinspoon’s book Earth in Human Hands does a bang-up job. The short version: the issue has boiled over several times in recent decades. And it may be about to boil over again:
Last month, a team of artists and scientists beamed out a message to exoplanet GJ 273 in hopes of interacting with intelligent alien life on the planet. Evidently, the team transmitted the message to GJ 273 over a span of three days and included math tutorials, 33 musical compositions, technology, and instructions on how the recipient may respond.
The star designated GJ 273 is better known to astronomers as Luyten’s, named after a key astronomer who found lots of faint red dwarfs. GJ 273 is nearby in cosmic terms, about 12 light-years away from our sun, and it’s one of the largest red dwarfs possible. Meaning if it were even a little bit more massive, the star’s internal dynamics and external characteristics would shift dramatically due to a tipping point buried down in the weeds of advanced astrophysics.
The traditional SETI program is a community and effort centered on detecting alien radio transmissions by listening. Its wilder sibling, Messaging to Extra-Terrestrial Intelligence or METI, takes it one step farther and sends messages specifically configured for aliens to detect and, hopefully, understand. This is a controversial practice. Jump below and we’ll give you the nickel tour on all that and more.
This incident wasn’t the first interstellar message intentionally sent to the stars. Not by a long shot. One of the most well known was the the Arecibo message of 1974. This was a 1679 bit signal with embedded mathematical hints on how to view it that was beamed toward the M-13 globular cluster in the constellation of Hercules. Since M-13 is over 22,000 light-years away, it will be sometime before any return message could be received! But our technology and understanding of exo-solar systems has greatly improved since then. We now know of dozens of nearby solar systems where there could be terrestrial planets or moons.
Should we start phoning ET’s home?
A number of scientists worry about that, including famous ones like Stephen Hawking. One chief concern boils down to “why draw attention” to ourselves? If we assume aliens exist with sufficient technical know-how to build radio-telescopes and decipher a METI message, we have no idea how advanced their capabilities might be or what their motives are. They could be natural xenophobes, utterly hostile by instinct to other intelligent species. Earth’s biosphere would be relatively easy to wreck form space. Beserker robots or deadly Von Neumann devices could soon be on their way, cosmic terminators, design to wipe us out any number of ways.
Other scientists argue that METI is fine to consider, but there should be a firm consensus, at least in the scientific community and, ideally, among the lay laypublic, for both practical and moral reasons. On the practical side, a coordinated effort across the existing SETI community would be far more efficient than one-off messages. From the perspective of public good, METI could theoretically impact all of us, and should therefore should be decided by large groups as opposed to a handful of scientists acting unilaterally.
In early 2015 a number of scientists and authors released a statement that read in part that a “worldwide scientific, political and humanitarian discussion must occur before any message is sent." METI advocates often point out that that is an unrealistic precondition, noting that the entire world rarely agrees on anything, and that few people outside the scientific community would care one way or the other.
Another argument made by METI advocates is that humans have been sending easily detectable, powerful radio and TV signals into space in every direction for decades already, i.e., the cat is long out of the bag, and so it’s a moot point. The first part is a fact of physics: a big dish like the one in Arecibo, Puerto Rico, could detect the carrier waves of countless prime-time sitcoms and crime drama programs from thousands of light-years away. It’s not exactly comforting to imagine advanced aliens could be receiving episodes of I Love Lucy or Wheel of Fortune right now. But it begs the question; if we’ve already sent such signals, why bother with METI in the first place?
All it takes to send a message is access to a decent transmitter and some imagination on how to best configure it in such a way that non-humans might be able to put it together as intended. The language of mathematics and science offers numerous ways to do that. And as yet there is no international board of overseers with any kind of authority and enforcement ability to do much about it. So, odds are more messages will be sent. If ET is out there, listening, it’s just a matter of time before he, she, or it detects something we sent regardless if if it was intentional or not. Some of you might be young enough to be around when and if a response ever arrives. What an interesting day that will be!