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Bringing the Universe to Your Classroom!

Monday, April 1, 2019

"Where Is Everybody?!"

The answer to the question, "If there are, other, intelligent civilizations out there - why haven't we detected any kind of signals from them?", is best answered, I think, by Seth Shostak, astronomer/astrobiologist and director of the SETI Institute in his 2009 book, Confessions of an Alien Hunter: A Scientist's Search for Extraterrestrial Intelligence.

I have learned (finally), that if I have to ask a question that, I feel, should have an obvious, up-front, readily available answer - but there doesn't seem to be one - then I'm missing something - usually, something embarrassingly fundamental - and that I should either know better - or, have kept my big mouth shut, and researched it, beforehand!! I can't tell you how many times this has happened to me.

SETI’s mission to seek out evidence of extraterrestrial life in order to understand and explain the origin of life in our universe. Graphic by Evolving Science.
SETI’s mission to seek out evidence of extraterrestrial life in order to understand and explain the origin of life in our universe. Graphic by Evolving Science.

But I have learned, that: I don't know everything. That, all is not obvious -  just because I want it to be. And, that variables exist - just to be variables - and just because they can be, that's all! (Or so it seems, sometimes).

I am very familiar with large - outrageously large - numbers. I've got a good grasp on what it means, that: the Moon is 237,000 miles from Earth, and that Earth is 92.8 million miles from the Sun. I've even seen, with my own eyes, what a million looks like; so, I have good imagery of what a million marbles, or better, a million Hershey bars, looks like. I've got numeric multiples memorized, all the way up to "undecillion" (1,000,000,000,000,000,000,000,000,000,000,000)! So, when I read that the SETI (the Search for ExtraTerrestrial Intelligence) organization has monitored, hundreds of thousands of stars, for electromagnetic spectrum signals, I figured that was more than enough to find what they were looking for. And if they haven't found anything by now, it's probably not going to happen.

The Search for Extraterrestrial Intelligence (SETI) Official Logo.
The Search for Extraterrestrial Intelligence (SETI) Official Logo.

About a month ago, I had e-mailed Seth regarding the progress of SETI, since the advent of the discovery of more than 4,000 exoplanets, out there in our Milky Way galaxy. He told me that the discovery is a big plus for SETI because now they can be more directional with their listening equipment. He also reminded me that, all of the hundreds of thousands of stars that SETI has monitored, against the number of stars still available for monitoring, represents a ratio, analogous to one grain of sand - from an entire beachful!

In other words, given the number of stars in the Milky Way galaxy (approximately 300 billion), SETI has only just begun. The number of potentials, calculated intelligent civilizations in the Milky Way (using the Drake equation formula), easily fits within the remainder of stars left to monitor. In fact, compared to the rest of the Milky Way in the context of the number of possible, intelligent civilizations - it's almost empty. It will be like finding the proverbial needle in a haystack. Needless to say, happily - my capacity for numbers is not as great as I once thought it to be!

By Dale Alan Bryant

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