Most folks are familiar with S.E.T.I. (Search for Extraterrestrial Intelligence), and when discussing it myself, one of my very favorite examples to give is perhaps the most famous imagery associated with it; large arrays of radio transmitters and satellite dishes. However, fewer people realize that, much like a regular conversation, communication with possible extraterrestrials can go two ways, also.

Active SETI (also known as METI, or “Messaging to Extra-Terrestrial Intelligence”) consists of the act of sending signals into space, with the intention of aliens receiving them. But is this practice dangerous?

Stephen Hawking, in his book A Brief History of Time, suggests that “alerting” extraterrestrial intelligences of our existence is not only dangerous, but that it’s also foolhardy. Apparently, according to Hawking, mankind’s history of how we treat other cultures less technologically proficient than us provides the best comparison. He bluntly suggests that we “lay low”. After all, even if aliens weren’t hostile and trying to kill us, they may very well occupy Earth, and pluck us like beets from the ground to be chartered in a anti-graviton wagon to the nearest (at least semi) habitable mudball; a “reservation” of sorts, where we humans can live as we please. So sadly, this sounds so familiar. Perhaps we learn things from history after all…

But I digress. Recently, some excellent commentary was given by Kevin Grazier, a physicist and Hollywood sci-fi adviser, to Discover Magazine while looking at how we could communicate with any aliens we Earthlings might encounter:

Both knowingly and unwittingly, humans have been broadcasting their presence to the Universe since the 1920s—when coherent transmissions in the radio portion of the electromagnetic spectrum became widespread. Our radio and television broadcasts do not stop at the edge of Earth’s atmosphere; rather they propagate into space at the speed of light. While these signals attenuate with distance, they are detectable nevertheless: NASA still regularly communicates with the twin Voyager spacecraft despite the fact that they are over 100 times further from the Sun than Earth and that each of which transmit data to Earth with less power than a common household light bulb. This means that an alien civilization as far away as 58 light-years could potentially be trying to make sense of “Lucy, you’ve got some ‘splainin’ to do!” (There are 105 G-type stars—ones like our own lovable Sol—within this I Love Lucy-sphere.)

In essence, Grazier points out that aliens might already be intercepting out light-speed “transmissions”, a notion already explored in films like The Arrival, or more appropriately in the case of illustrating risks of METI, Contact, based on Carl Sagan’s novel in which a message received as a sequence of prime numbers is revealed to be a “call back” using our own broadcast of Adolf Hitler’s welcoming address at the 1936 Summer Olympics in Berlin. If ever there could be imagined a better ambassador for humankind… that thought alone may be as frightening as any hostile aliens who might receive such a message. Therefore, is concern over what gets funneled out into space as electromagnetic “waste” a valid point, or is it merely an illustration of our growing paranoia? Hopefully, any significantly advanced race of beings with technology capable of actually reaching us would harbor morals as sound as their intellect… but on that point, we can only hope for the best.