There have been several messages broadcast into space or placed on board deep space probes intended for any attentive aliens out there. But we shouldn’t be narcissistic when it comes to crafting interstellar greetings, says a group of researchers in a recent science paper. They argue that if we are, E.T. simply won’t understand what we’re trying to tell them.
Take the aluminum postcard plaque aboard the star-bound Pioneer 10 and 11 probes (pictured above). The most dominant graphic is an engraving of man and woman, his hand upraised in a greeting gesture. This is hardly a universal gesture especially if the aliens who find it have no limbs. Or it could be taken as downright obscene in some corners of the Galaxy.
The plaque always has a high giggle factor when I show it to my Astronomy 101 classes. “The aliens are going to think we don’t wear any clothes!” said one student.
And that’s just the point, says authors Dimitra Atri, Julia DeMarines, and Jacob Haqq-Misra, who warn that interstellar information that means a lot to us may be inscrutable to E.T. because it is too culturally overloaded.
“Many people would choose to construct a message containing sights and sounds of the human experience but overly anthropocentric signals that implicitly rely upon certain facets of human culture may go unnoticed by extraterrestrial listeners,” writes Atri, of the University of Kansas.
“Messages that rely on the specifics of human biology or culture will be less likely to effectively communicate to an unfamiliar extraterrestrial listener. This may require that the message attempts to represent Earth as a whole instead of focusing exclusively on humanity.”
The researchers favor using two specific radio wavelengths for transmission which are commonly observed in nature and easy to pick up. They also recommend establishing a dedicated radio transmission beacon that can paint the sky and revisit stars with regular broadcasts. Lasers offer a powerful signal that stands out from the sky background, but they can only be used for specific stellar targets.
It’s unlikely anyone out there will find the twin Pioneer and Voyager probes that carry simple notes-in-bottles. But we have sent several radio transmissions to the stars.
For example, in 1993 and 2003 two interstellar radio messages were broadcast from a 70-meter radio telescope in the Ukraine. It targeted nine nearby stars, including the sun-like 55 Cancri, which I bet could host a civilization on one of its five planets.
The transmission included musical melodies performed on the theremin, an electronic audio instrument that was used to make the soundtrack for the original film “The Day The Earth Stood Still,” among other sci-fi movies. Would extraterrestrial really like listening to melodies that we imagine epitomize aliens? The signal also contains bilingual Russian and English greetings to extraterrestrials.
The scientists say that another problem is in our assumption that aliens can properly perceive pictures or sounds with their own unique sensory organs.
The most straightforward message we can send is one steeped in fundamental science. Maybe we should simply encode our value for the expansion of the universe, or the equation of state of dark energy -– something alien astronomers everywhere want to know.
Sounds boring. But do aliens really need to listen to Michael Jackson or decode pictures of lilies? Comedian Grouch Marx put it succinctly when he said, “My favorite poem is the one that starts ‘Thirty days hath September’ because it actually tells you something.”
The most scientific radio message for E.T. ever sent out was the Arecibo radio telescope transmission in 1974. The binary message was encoded to be displayed as a pictogram that somewhat resembles a vintage Atari video game display. Persevering alien scientists could decipher such information as the atomic numbers of the five basic elements of life, the number of nucleotides in DNA complete with a graphic of it double helix structure, a schematic of the solar system, and an Atari-looking human block figure.
What I’ve learned in my classes, and what the researchers insist, is that an effective message to extraterrestrials should at least be understandable by humans. Therefore sample prototype messages should be posted and tested on the Internet, they say.
Through an interactive website, users from around the world could create their own messages that conform to a pre-established protocol. Messages submitted through the website could then be retrieved by other users, who would then attempt to decrypt the message to see if the communication was successful. Messages would travel across cultural boundaries.
“Although this process will not remove all anthropocentric bias, it will help identify some cultural biases in the test messages,” reports Atri.
The silliest interstellar communication exercise to date was a social networking site’s PR stunt called “A Message From Earth.” In 2008 a radio signal was sent towards the super-Earth planet Gliese 581c. A total of 501 text messages, photographs, and drawings were selected to be transmitted from over 1 million Internet entries from people all over the world.
Among the more mawkish messages:
“Humans are naive and fragile.”
“We want to be friends.”
“If you come to Earth look into music, hugs, dancing, the beach… books and dreams.”
“We are but children with so much to learn.”
Boy, Prof. Hawking, if that’s not an open invitation for aliens to come here and reopen Earth under new management, I don’t know what is.
SETI veteran Seth Shostak recently said that if we want to tell E.T. about our culture, we should simply transmit two days worth of Internet traffic from the Google site. That’s guaranteed to befuddle any form of intelligent life, no matter how advanced.
In hindsight, aliens might glean a better understanding of that Pioneer plaque sketch after all.