Sciency Words A to Z: METI

April 15, 2019April 12, 2019 ~ 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.

Sciency Words A to Z: LGM-1

April 13, 2019April 12, 2019 ~ J.S. Pailly ~ 6 Comments

LGM-1

In the mid-1960’s, Jocelyn Bell (later known as Jocelyn Bell Burnell) was a grad student at Cambridge. Through Anthony Hewish, her Ph.D. advisor, she became involved with the construction and operation of a brand new radio telescope specially designed to hunt for quasars. But that telescope ended up finding something more than just quasars.

Bell Burnell recounts the story in this speech, as published by Cosmic Search Magazine. Part of her job was analyzing data from the telescope, which came in the form of chart paper—literally miles worth of paper—produced by a set of “3-track pen recorders.” And on those chart papers, Bell saw some odd markings, which she described as bits of “scruff.”

Naturally, that scruff required further investigation. Faster, more accurate recordings were made, and the scruff resolved itself into a series of regular radio pulses. These pulses were so consistent, so evenly spaced, that you’d think they must be artificial. It was almost like someone out there in space was trying to get our attention!

Bell named the source of those radio pulses LGM-1, which stood for little green men #1. But as I said in a previous post, when it comes to discovering alien life, scientists must hold themselves to the same standard as a court of law: proof beyond a reasonable doubt. While Bell may have been happy to joke about little green men, she did not actually believe that’s what she’d discovered. As she explained in her speech:

Just before Christmas I went to see Tony Hewish about something and walked into a high-level conference about how to present these results. We did not really believe that we had picked up signals from another civilization, but obviously the idea had crossed our minds and we had no proof that it was an entirely natural radio emission. It is an interesting problem—if one thinks one may have detected life elsewhere in the universe how does one announce the results responsibly? Who does one tell first?

After her Chistmas break, Bell returned to work and found a big pile of fresh data to analyze, and there was more “scruff.” In total, Bell found four distinct radio sources, located in completely different parts of the sky.

And that finally put the “little green men” hypothesis to rest. It seemed highly unlikely that four different alien civilizations, located in completely different regions of space, would all try to get our attention at the exact same time, in the exact same way, using the exact same radio frequencies.

LGM-1 is now believed to be a neutron star, spinning rapidly, projecting twin beams of radio waves out into space like some sort of cosmic lighthouse. It’s an entirely natural phenomenon, the result of a supernova explosion. Today, we call this sort of object a pulsar.

Next time on Sciency Words A to Z, maybe it’s time to stop waiting for aliens to contact us. Maybe it’s time we tried to contact them.