Experts predict there are 36 contactable alien civilizations. Seriously.
Astrophysicists calculate the likely number of civilization out there capable of communicating with us.
- Taking into account what we do know, and mixing in some assumptions about life on Earth, a team of scientists have made predictions about alien life.
- Even if aliens are relatively close by, they and we would have to be around for over 6,000 years just to chat.
- Our current technology will likely not allow us to communicate with anyone or thing.
"The Ultimate Answer to Life, The Universe and Everything is...42!" — supercomputer Deep Thought in Douglas Adams' "Hitchhiker's Guide to the Galaxy"
Thus began a grand experiment involving humans and pan-dimensional, hyperintelligent mice designed to figure out more exactly what the question was anyway. As if in tribute to Adams, a group of astronomers this week announced their answer to a Great Question, and it is 36. This time, though, we at least know what the question is: How many contactable alien civilizations are there in our galaxy? But 36?
"I think it is extremely important and exciting because for the first time we really have an estimate for this number of active intelligent, communicating civilizations that we potentially could contact and find out there is other life in the universe — something that has been a question for thousands of years and is still not answered."
So says astrophysicist Christopher Conselice of University of Nottingham. He's co-author of a report published in the Astrophysical Journal, and Nottingham and his colleagues are dead serious about the 36 likely Communicating Extra-Terrestrial Intelligent (CETI: pronounced "chetee") civilizations.
The Drake Equation
Image source: Google
The scientists' calculations are a response to the Drake equation. In 1961 astronomer Frank Drake proposed that having knowledge of seven factors would allow scientists to reasonably estimate the number of intelligent alien civilizations out there. The Drake equation is so named because it's a mathematical formula, shown above. The seven factors are:
N = number of civilizations with which humans could communicate
R * = mean rate of star formation
f = fraction of stars that have planets
ne = mean number of planets that could support life per star with planets
fl = fraction of life-supporting planets that develop life
fi = fraction of planets with life where life develops intelligence
fc = fraction of intelligent civilizations that develop communication
L = mean length of time that civilizations can communicate
Even today, a lot of these blanks remain unfillable with our current knowledge. "Drake equation estimates have ranged from zero to a few billion [civilizations]— it is more like a tool for thinking about questions rather than something that has actually been solved." So Conselice and his colleagues set out to refine the equation based on what we do know, the one environment we're certain supports life as we know it: Earth.
The Astrobiological Copernican Principle
Image source: Christoph Burgstedt/Shutterstock
The Astrobiological Copernican Principle is based on the notion that what worked here could work elsewhere. "Basically, we made the assumption that intelligent life would form on other [Earth-like] planets like it has on Earth," Conselice tells The Guardian, "so within a few billion years life would automatically form as a natural part of evolution."
On the other hand, the report concludes these planets would be more likely to be orbiting low-mass M dwarf stars than strong stars like our Sun, and these dwarves are less likely to be life-supporting over an extended period.
"[If intelligent life] in a scientific way, not just a random way or just a very unique way, then you would expect at least this many civilizations within our galaxy." Such alien life might be more like off-planet "Star Trek" guest stars than, say, squid. Conselice says, "We wouldn't be super-shocked by seeing them."
Of course, begins the report, "One of the oldest questions that humans have asked is whether our existence—as an advanced intelligent species—is unique."
Getting to 36
Image source: metamorworks/Shutterstock
The study authors operated on the assumption that a planet's life would have to take form between 4.5 billion and 5.5 billion years after the creation of its system's star, as it did here. We've only been producing radio waves to send out there for 100 years, so that's assumed to be about the minimum time a civilization would have to be in existence and broadcasting for us to detect them, but really much longer — it's not as if we crawled out from the primordial ooze with radios.
More realistically, the authors expect that a CETI population would have to exist for an average of 3,060 years to be detectable, which means that if life formed in both places at the same time, we'd both need to be in existence for 6,120 years (beyond that minimal 100 years) for a single "Hi, we're from Earth," "Hi, we're not" exchange to occur.
The report is, understandably, mostly being met with a shrug, at least according to three experts who checked in with The Guardian. "[The new estimate] is an interesting result, but one which it will be impossible to test using current techniques," says Andrew Coates of the Mullard Space Science Laboratory at University College London, though he agrees that the report's assumptions were reasonable. Patricia Sanchez-Baracaldo of University of Bristol notes just how many things have to go right for life to happen as it has here, suggesting that this additional what-if that makes accurate estimates even more difficult. Oliver Shorttle of the University of Cambridge cited the significant unanswered questions we would need to know the answers to in order to really hazard an irrefutably plausible estimate of CETI civilizations.
But we do have one answer, at least: 36. Sorry, two. Let's not forget 42.
Update, or What Smart People Do for Fun: Steven Wooding of U.K.'s Institute of Physics sent us the link to an online alien civilization calculator that he and his friend, molecular physicist Dominik Czernia, cooked up. It works with both of the models mentioned in this article to deduce the likely number of contactable civilizations given a set of variables. Enjoy!
- Dark Forest theory: Why aliens haven't contacted us - Big Think ›
- Great Filter theory: Why we haven't found alien life - Big Think ›
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Join Radiolab's Latif Nasser at 1pm ET on Monday as he chats with Malcolm Gladwell live on Big Think.
University of Utah research finds that men are especially well suited for fisticuffs.
- With males having more upper-body mass than women, a study looks to find the reason.
- The study is based on the assumption that men have been fighters for so long that evolution has selected those best-equipped for the task.
- If men fought other men, winners would have survived and reproduced, losers not so much.
Built for mayhem<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjY2NDIyMy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxMzk4NTQ2OX0.my6nML12F3fEQu3H4G0BScdqgaMZkRQHxgyj-Cmjmzk/img.jpg?width=980" id="906fc" class="rm-shortcode" data-rm-shortcode-id="dd77af7a881631355ed8972437846394" data-rm-shortcode-name="rebelmouse-image" />
Image source: Ollyy/Shutterstock<p>The researchers are, of course, talking averages here, not stating a rule: There are plenty of accomplished female pugilists, as well as lots of males who have no idea how to throw a punch.</p><p>Even so, says co-author <a href="https://www.wofford.edu/academics/majors-and-programs/biology/faculty-and-staff" target="_blank">Jeremy Morris</a> says, "The general approach to understanding why sexual dimorphism evolves is to measure the actual differences in the muscles or the skeletons of males and females of a given species, and then look at the behaviors that might be driving those differences."</p><p>Carrier has been interested in the idea that millennia of male fighting has shaped certain structures in male bodies. Previous research has reinforced his hunch:</p> <ul> <li><a href="https://jeb.biologists.org/content/216/2/236" target="_blank">When a hand is formed into a fist, its structure is self-protective</a>.</li> <li><a href="https://unews.utah.edu/flat-footed-fighters/" target="_blank">Heels planted firmly on the ground augment upper-body power</a>.</li> <li><a href="https://www.ncbi.nlm.nih.gov/pubmed/24909544" target="_blank">A study examined facial bone structure as being especially well-suited for taking a punch</a>.</li> </ul> <p>(That last one is our favorite. Do you know the German word "<a href="https://www.urbandictionary.com/define.php?term=Backpfeifengesicht" target="_blank">backpfeifengesicht</a>?" It's an adjective describing "a face that badly needs a punching.")</p><p>"One of the predictions that comes out of those," asserts Carrier, "is if we are specialized for punching, you might expect males to be particularly strong in the muscles that are associated with throwing a punch."</p>
Testing the theory<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjY2NDIzMy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYwNzMxMTE2MH0.UXJICMy57UPYUWskhK98alctOrPidJL9yxMkz3HDQrM/img.jpg?width=980" id="98718" class="rm-shortcode" data-rm-shortcode-id="b12287684ac3e740b70392e6433a6b8f" data-rm-shortcode-name="rebelmouse-image" />
Image source: Ollyy/Shutterstock<p>The researchers measured the punching — and spear-throwing — force of 20 men and 19 women. The assumption was that early humans were punchers <em>and</em> spear-throwers.</p><p>Prior to testing, each participant had filled out an activity questionnaire so that "we weren't getting couch potatoes, we were getting people that were very fit and active," says Morris.</p><p>For punching, participants operated a hand crank that required movement similar to throwing a haymaker. The purpose of the hand crank was to spare participants any damage that might be inflicted on their fists by throwing actual punches. Subjects were also measured pulling a line forward over their heads to assess their strength at throwing a spear.</p><p>Even though all of the participants, male and female, were routinely fit, the average power of males was assessed as being 162% greater than females. There were no gender differences in throwing strength recorded. Other untested, though presumably likely, hand-to-hand combat activities come to mind including tackling, clubbing, running, kicking, scratching, and biting.</p><p>Carrier's takeaway: "This is a dramatic example of sexual dimorphism that's consistent with males becoming more specialized for fighting, and males fighting in a particular way, which is throwing punches."</p>
Boys will be boys<p>It, er, strikes us as odd that, even in science fiction — hi-tech weaponry notwithstanding — the hero <em>is</em> going to wind up duking it out with some bad guy, or alien, in the climactic battle. What is it about men punching, anyway? Are they more sexually attractive? The study suggests so:</p><p style="margin-left: 20px;"><em>The results of this study add to a set of recently identified characters indicating that sexual selection on male aggressive performance has played a role in the evolution of the human musculoskeletal system and the evolution of sexual dimorphism in hominins.</em></p><p>It's tough to contribute to the gene pool after being killed in battle.</p><p>Also, while the authors aren't <em>quite</em> saying that males' historical fighting role is mandated by biology and not by social expectations, neither are they quite <em>not</em> saying it.</p><p>As Carrier explain to <a href="https://attheu.utah.edu/facultystaff/carrier-punch/" target="_blank">theU</a>: "Human nature is also characterized by avoiding violence and finding ways to be cooperative and work together, to have empathy, to care for each other, right? There are two sides to who we are as a species. If our goal is to minimize all forms of violence in the future, then understanding our tendencies and what our nature really is, is going to help."</p>
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Cool hand rebuke<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDQyMTIyNy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NjY1NTYyOH0.0MCPKN3If94mYCNf3mMNrnTvJXjXN_bKLhgk9203EXk/img.jpg?width=917&coordinates=0%2C0%2C0%2C0&height=453" id="1627b" class="rm-shortcode" data-rm-shortcode-id="6d76421ba1ea0de4b09956b97e80c384" data-rm-shortcode-name="rebelmouse-image" />
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