Dr. Leif Svalgaard advises us of this paper via email. Apparently some people want to ring the “cosmic dinner bell” by broadcasting powerful radio transmissions to get the attention of possible extra-terrestrial civilizations. This paper sums up the argument.
The Very Large Array (VLA) of radio telescopes at night.
There is an ongoing debate pertaining to the question of whether Earth should initiate intentional and powerful radio transmissions to putative extra-terrestrial (ET) civilizations in the hope of attracting ET’s attention. This practice is known as METI (Messaging to ET Intelligence) or Active SETI. The debate has recently taken on a sense of urgency, as additional proponents have announced their intention to commence de novo transmissions as soon as they become funded and acquire the needed time on a powerful transmitter such as Arecibo. Arguments in favor of METI are reviewed. It is concluded that METI is unwise, unscientific, potentially catastrophic, and unethical.
In the medical sciences, proposed experiments must pass ethics review boards. Some experiments are simply too dangerous or unethical to be performed, certainly not just on one’s own lonely say-so. We do not clone humans; we do not conduct table top experiments with smallpox; and we no longer inject human subjects with pathogens in order to trace the course of a disease or to see how long it might take for subjects to die. Though a commonplace in medical research, astronomers face no such ethical reviews, since theirs is normally an observational science only. When it comes to METI (Messaging to ET Intelligence, also called or Active SETI), which is not observational but manipulative, and on which may hinge the very fate of the world, perhaps they should.
Do space aliens present a clear and present danger and, if so, is there anything we can do about it? There is not one scintilla of credible evidence that Earth has ever been visited by space aliens, much less that aliens have sought to do damage to the Earth. However, extraterrestrials (ET), if they exist, may soon learn that Earth harbors technologically advancing life forms, and that may change everything. Our electromagnetic (EM) emissions leave Earth at the speed of light. EM that left Earth in 1930 has already swept over approximately the nearest 7,000 stars.
That said, Earth’s EM leakage is either very weak, not pointed at nearby stars, or both. Further, the Earth grows quieter annually as more information is transmitted via cable, the Internet, and satellites rather than terrestrially over the air. Unless ET’s receivers are both powerful and omnidirectional, they will not detect us.
ET’s receivers could be omni-directional, but unable to pick up a signal so weak as the proverbial I Love Lucy. For example, the gigantic Arecibo radio telescope could not detect terrestrial TV transmissions, if broadcast from the distance of our nearest neighboring stars. Alternatively, an ET receiver could be very powerful, but it might take millennia for it to get around to slewing in our direction, given the large number of potential targets. By the time Earth returns into ET’s crosshairs for a routine check in, we might have gone silent.
The first modern SETI search was conducted by Frank Drake in 1960 . From that date until today, there has been no agreed upon detection of an alien signal. Some are now arguing that since so much time has elapsed without success, it is time to announce ourselves to ET by using our most powerful radio telescopes as transmitters in order to proactively send our signals to Earth’s nearest stars in an effort to attract ET’s attention. Arecibo, for instance, is so powerful that, when used as a transmitter, its signal is potentially capable of being detected at vast interstellar distances.
A new consideration of the METI debate assumes some urgency at this time. When the SETI Institute (SI) rejected a proposal from Vakoch and Shostak to initiate immediate high power radio transmissions directed to Earth’s neighboring stars, Vakoch founded another organization, METI International [2, 3], with the same intent [4, 5]. Fearing a gathering storm, a cohort of SETI scientists and thinkers issued a statement in opposition to METI in February, 2015 . John Gertz
The current paper will further consider the arguments of METI’s proponents (METI-ists) and opponents.
Whenever one hears a “scientist” assert that ET must be altruistic, or that ET surely knows we are here, or that the closet ET civilization is at least x LY away, ask to see the data set on which they base their conclusions. As of today, no such data set exists. In the absence of any evidence whatsoever, whether one believes that the extraterrestrial civilization we might first encounter will be benign, in the fashion of Spielberg’s Close Encounters of the Third Kind, or ET, or malicious, as in Ridley Scott’s Alien, or robotic, or something else entirely is strictly a matter of one’s personal taste. SETI experiments seek to learn what actually resides or lurks out there in the universe. METI plays Russian roulette without even knowing how many bullets are in the chamber.
It would be wiser to listen for at least decades if not centuries or longer before we initiate intentional interstellar transmissions, and allow all of mankind a voice in that decision. The power of SETI has grown exponentially with Moore’s Law, better instruments, better search strategies, and now thanks to Milner’s visionary investment, Reviewing METI: A Critical Analysis of the Arguments meaningful funding. The advances are so profound that it is reasonable to say that the SETI of the next 50 years will be many orders of magnitude more powerful than the SETI of the last 50 years.
Shostak, perhaps METI’s most articulate proponent, knows this and has widely predicted that we will achieve Contact within the next two decades. So why can he and his fellow METI-ists not wait at least until then before initiating transmissions?
A METI experiment based on an actual methodology that includes a plan to receive ET’s reply, might leave some to call that method madness, but at least it would qualify as actual science. Sending a message without a practical plan in place to receive a return message, leads to the conclusion that METI transmissions are like a Hail Mary, they have more in common with a faith based religion than with science. METI-ists implicitly believe that ET is omniscient (they know we are here even though our leakage is trivial); all good (ET must be altruistically interested in our welfare); and omnipotent (even though we have made no provision to receive their return message, they will make themselves known to us somehow). It is fair to ask that METI- ists not impose their religion on the rest of us.