Tag: Arecibo message

Sciency Words: CETI vs. SETI

~ J.S. Pailly ~ 9 Comments

Hello, friends!  Welcome back to Sciency Words, a special series here on Planet Pailly where we take a closer look at the definitions and etymologies of scientific terms.  Today on Sciency Words, we’re talking about:

CETI

On October 10, 1966, scientists from the International Academy of Astronautics met in Madrid, Spain, to discuss CETI: Communications with ExtraTerrestrial Intelligence.  This was surely not the first time the term CETI was ever used, but based on my research, that 1966 meeting seems to be the earliest official usage of the term by the scientific community.

CETI refers to the act of sending signals or messages out into space for the express purpose of making contact with intelligent alien life.  It’s the human race shouting into the void, asking if anybody’s out there.  The most famous example of this is the Arecibo message, which was broadcast from the Arecibo radio telescope in Puerto Rico in 1974.

The idea of deliberately trying to attract the attention of extraterrestrials has always been controversial.  What if an alien intelligence does hear us?  What if that alien intelligence is not friendly?  But for the purposes of a Sciency Words post, I’m going to skip over that controversy and focus on the controversy about the word CETI itself.

CETI is far too easily confused with SETI (the Search for ExtraTerrestrial Intelligence).  CETI and SETI are closely related fields, but there’s one very important distinction between them.  It’s the difference between talking and listening.  CETI is about trying to talk to the rest of the civilized universe (assuming other civilizations exist, of course).  SETI is about listening patiently to see if anyone out there is trying to talk to us.

According to Google ngrams, the term CETI peaked in the late 1970’s/early 1980’s.  Since then, the term METI (Messaging ExtraTerrestrial Intelligence) has far surpassed CETI.  And in 2018, a special committee on SETI nomenclature recommended that CETI be dropped from scientific discourse in favor of METI.

And yet CETI still appears, from time to time, in scientific research.  For example, this paper from June of 2020 uses the term CETI extensively.  But we’ll talk about that paper more on Monday.  It makes some rather bold predictions about how many CETI-capable civilizations should exist in our galaxy at this very moment.

P.S.: The authors of that 2020 paper offer another solution to the CETI vs. SETI problem.  They suggest CETI should be pronounced as “chetee.”  I’m not sure how I feel about that.

P.P.S.: Actually, I am sure how I feel about that.  I’d rather use the term METI instead.

Sciency Words A to Z: METI

~ J.S. Pailly ~ 14 Comments

Welcome to a special A to Z Challenge edition of Sciency Words!  Sciency Words is an ongoing series here on Planet Pailly about the definitions and etymologies of science or science-related terms.  In today’s post, M is for:

METI

In a sense, SETI researchers are just sitting by the phone waiting for somebody to call.  Maybe that’s the wrong way to go about it.  Maybe it’s time to pick up the phone, start dialing numbers, and see who picks up.

This idea is sometimes called active SETI, but it’s more common (and according to this paper, more appropriate) to use the term METI: the messaging of extraterrestrial intelligence.

Earth has been broadcasting TV and radio signals for over a century.  This has led to a common misconception that even now, aliens on some far off planet might be gathering around their equivalent of a television set, watching old episodes of Howdy Doody  or The Honeymooners.  Or perhaps, if the aliens live nearby, they’re currently listening to our more recent music.

But Humanity is only a Type 0 or Type I civilization, depending on which version of the Kardashev scale you’re using. Either way, our broadcasts are not actually that strong.  As David Grinspoon explains in his book Earth in Human Hands:

Our television signals are diffuse and not targeted at any star system.  It would take a huge antenna, much larger than anything we’ve built or planned, to pick up on them.  From a radio point of view our planet is not completely hidden, but it is hardly conspicuous.  This could easily change.  Targeted messages sent directly toward nearby stars would cause Earth suddenly to turn on like a spotlight, becoming an obvious beacon announcing, for better or worse, “We are here!”

Of course we’ve already done this.  Several times, in fact.  But not with enough consistency to truly make our presence known.

The first attempt was in 1974, when Frank Drake and Carl Sagan transmitted a message from the Arecibo radio telescope in Puerto Rico, aimed at the M13 globular cluster.  But according to Grinspoon, if aliens ever do pick up that signal, “[…] they might dismiss it as a momentary fluke.  We would.”  That’s because the Arecibo message was a quick, one-time thing.  By itself, it’s hardly proof beyond a reasonable doubt that life exists on Earth.

If we really want to get somebody’s attention, we have to send a sustained, repetitive signal, kind of like those repetitive radio pulses Jocelyn Bell detected in the 60’s.  We have the technology.  We can make METI a reality.  But should we?  Some say yes, others no.  After all, we have no idea who might hear our signal, or what form their response might take, and there is no guarantee that the aliens will be friendly.

METI is a discussion and a debate that maybe we all, as a species, should be part of.  Perhaps we should take a vote, because in the end, we all have a stake in what might happen.  And while we’re at it, there are some other issues we all, as a species, should vote on.  Or at least that’s what Grinspoon says we should do in his book.

Next time on Sciency Words A to Z, we’ll go back in time and check out the oceans of Mars.