‘A copernican answers Fermi’ (updated 21nov18)

“Any sufficiently advanced technology is indistinguishable from magic.” – A.C. Clarke’s Third Law

George Rebane

Last month we were encamped with two other couples at Hat Creek in northern California.  It was a delightful trip – the weather was fine, the food, drink, and the friends superb.  Actually, we’re all experienced “road warriors” having traveled much with each other over the last years.  This was our second trip to the Hat Creek RV Park which is located far away from cities and towns in the middle of a broad and very ancient volcanic caldera with walls reaching up several hundred feet.  Hat Creek is a quiet place with few people, but because it is located in a bowl, it is also quiet in the electromagnetic (EM) sense which is important to radio astronomers and people searching the galaxy for evidence of extra-terrestrial intelligence (ETI).

For that reason, the Hat Creek caldera is home to the Allen Telescope Array (ATA) that was built for the Search for Extra-Terrestrial Intelligence (SETI) Institute to support their ETI search program.  We men, of course, had to go visit the observatory since it was only about 1.5 miles from the RV park.  We drove over, went into the facility, talked to the staff, walked into the array of dishes, saw the data gathering and control equipment, and watched the obligatory video extolling the virtues of the radio observatory and its mission.  Then we took a lot of pictures, one of which you see here is a close up of one of dishes.

We were told that the ATA currently serves the radio astronomy needs of both the SETI Institute located in Menlo Park, and the Stanford Research Institute in Palo Alto.  The array signal feeds go directly to those locations for further analysis, and from there the surveillance directions for the array are transmitted.

After returning from our visit, my little feverish mind started recalling all the things I’ve been reading and thinking over the years about ETIs and the galaxy with multitudes of post-Singularity super-intelligences.  And the constant points that I always had to revisit was Drake’s formula for estimating the number of intelligent civilizations in the galaxy, and Fermi’s ‘Where are they?’ or ‘Where is everybody?’

Physicist Enrico Fermi’s question is even more poignant today than it was over sixty years ago when he first posed it to John von Neumann.  Because to date we have spent a lot of money and brainpower pointing sensitive radio telescopes at the sky, and we have heard nothing but radio noise – no sign of intelligent transmissions.  So, is there really anybody out there, or are we really alone?  What can explain the silence?

Years ago as a nascent physicist, I learned that there could be several other means than radio waves with which to conduct inter-stellar communications, and as a teenage sci-fi geek and junior cosmologist, I was already convinced that Earth and the solar system were not unique in our galaxy or, for that matter, in the universe.  It baffled me how anyone could think that in its formation from cosmic dust, our sun would be the only star to be born with a system of planets orbiting it.  To my mind, given what was known about the genesis of stars, a star without planets would have been the exception, and lo, that is how it has turned out with what we know today about stars and exo-planets.  So there had to be another reason for the silence. 

As we all learned more during the Cold War and from other scientific studies, there are many ways that an inhabited planet could ‘blink out’ and become an orbiting derelict, no longer home to intelligent life.  Books have been written about the diverse endings that civilizations may suffer.  Of course, the more salutary kind of blink outs would involve the purposive evolution, or transit if you will, of bio-intelligent species into super-intelligence that would begin with each civilization encountering its Singularity.  The bio-life would then recede as its super-intelligent successor became the dominant lifeform residing on some more convenient material stratum (not necessarily silicon).

From what I and others, those who have adopted that view of post-Singularity life, have gleaned is that the interval between starting EM transmissions and encountering Singularity would generously take about two of our centuries, 200 years.  It would take much less time for a civilization to destroy itself as we ourselves have ascertained on Earth.  So it seems to me that using 200 years as the nominal duration of EM transmissions before blink out is a reasonable number with which to define spreading EM annuli of 200 lightyears (ly) thickness emanating from planets with civilizations having destroyed themselves or successfully evolved to intelligence.

Adding some more numbers describing the age of our universe, our galaxy, our solar system, and all the distances that characterize our Milky Way galaxy, along with the speed of light, and it appeared that there was enough information for a bit of noodling that might yield some useful distributions that describe what our radio telescopes could encounter as they looked for ETI.  The long and short of it was that I had some time and recent motivation to sit down, push some squigglies, develop a simulation model or two, and code them up.  When I ran the simulations the very plausible answer explaining away SETI’s experience and answering Fermi’s question stared me in the face.  I won’t give away the punch line here, but if you’re interested in the answer and a short description of the journey there, please download the little paper that describes the whole thing -  Download A Copernican Answers FermiV21nov18 

Comments

[Russ]

More on SETI

When we moved to Lincoln, I purged my SETI library, but this spring I read the Eerie Silence: Renewing Our Search for Alien Intelligence by Paul Davies which was recommended by George.

Davies believes the search so far has fallen into an anthropocentric trap—assuming that an alien species will look, think, and behave much like us. If the evolutionary chain followed the dinosaurs we might all look more like lizards than apes.

Davies refocuses the search, challenging existing ideas of what form an alien intelligence might take, how it might try to communicate with us, and how we should respond if it does.

Davies asks the question, should we be looking for radio signals or for some far more advanced technology? He introduces the idea we could be looking for alternative phylogenies of life on Earth which could represent extraterrestrial life on our doorstep, seeded actively or inactively from beyond.

If you are at all interested in SETI, I recommend the Eerie Silence, it is highly rated on Amazon and comes in multiple Kindle formats. Love my Kindle. When big words are used by an author, I can highlight and get a quick definition and continue reading. A feature that worked well in the reading of this book.

[The Estonian Fox]

Good analysis in putting some numbers to it. But - people often struggle with decisions when the “right” answer from a numerical standpoint doesn’t feel like the right answer from an emotional standpoint.

One item that should go into the equations (not easily of course) is curiosity. We reached 7+ billion humans on earth because we keep asking those darn questions - how can we do this; how can we do that; how can we do that BETTER. And soon, there are 7 billion of us. Still breathing out that darn ol' CO2 making this a hell on earth. You probably weren't aware that hell had an average temp of 55F did you? Not so bad actually!

Lynn Margulis pointed out in a Biosphere II talk in 1990 that earth is unique in the solar system - because it has a certain non-reacted element in its atmosphere. It may be one of the rarest elements in the universe - free, un-reacted oxygen. Free oxygen is virtually non-existent on the other planets. Unlike the truth, which flourishes when it's set free, oxygen goes into hiding when it's free - it hides as part of a compound. Oxygen combines with anything, at any pressure, any temperature, any time. To have a large supply of it must mean something is continually producing it. It's been like that for over 500 million years. Breathing un-reacted oxygen is number one on my everyday list of things I like to do. Nothing else is even close. When our sensors are sensitive enough, we'll be looking for free O2 in exoplanet atmospheres. That's where we'll want to go. But only if we're curious.

If technology is akin to magic, then faster-than-light travel should certainly have become a reality somewhere, and it should be everywhere by now - at least for those 1000 nearby planets. Then anywhere becomes "right next door", in real time. So where are they? Maybe space travel is just incredibly difficult - no faster-than-light propulsion, no worm-holes, no teleportation. What's a guy to do? That may explain why no one came. It's just too hard to go anywhere. And certainly not in real time.

Have we been visited by intelligent life - at one time, or now? Not necessarily. We could have gotten where we are (intellectually) by ourselves. So after the singularity, what would prevent beings from coming here? Could they be so advanced that they know everything, and are not curious? Have they no explorers that would come just because we are there? Maybe we are uninteresting, and there is no curiosity on their part. If so, then why do we even care to meet them - what's in it for us? The end would be boredom for humans. How's that ever worked out well for us?

On the other hand, we may have had one such visitor 2000 or so years ago, who eventually disappeared without a trace. Was he here only to gather data to finalize a PhD thesis? If he made it here, where are the others?

[George Rebane]

EstonianF 630am - I bundled the unreacted oxygen and other unique attributes of Earth into the added 1e-4 factor that reduced the currently available planet population to under a 1,000. I agree with your other questions and dealt with most of them at the end of the linked paper. We have also covered the existence and activities of post-Singularity civilization in other RR posts over the years, which you might peruse and share your insights. Repeating myself, I'm willing to bet the ranch that, given the cosmic time spans involved, to the extent that we are interesting, super-intelligent beings are already among us.

[Russ]

Does Climate Change Explain Why We Don’t See Any Aliens Out There?

by Matt Williams

The study, titled “The Anthropocene Generalized: Evolution of Exo-Civilizations and Their Planetary Feedback“, recently appeared in the scientific journal Astrobiology. The study was led by Adam Frank, a professor of physics and astronomy at the University of Rochester, with the assistance of Jonathan Carroll-Nellenback (a senior computational scientist at Rochester) Marina Alberti of the University of Washington, and Axel Kleidon of the Max Planck Institute for Biogeochemistry.

Today, Climate Change is one of the most pressing issues facing humanity. Thanks to changes that have taken place in the past few centuries – i.e. the industrial revolution, population growth, the growth of urban centers and reliance on fossil fuels – humans have had a significant impact on the planet. In fact, many geologists refer to the current era as the “Anthropocene” because humanity has become the single greatest factor affecting planetary evolution.

In the future, populations are expected to grow even further, reaching about 10 billion by mid-century and over 11 billion by 2100. In that time, the number of people who live within urban centers will also increase dramatically, increasing from 54% to 66% by mid-century. As such, the quesiton of how billions of people can live sustainably has become an increasingly important one.

Prof. Frank, who is also the author of the new book Light of the Stars: Alien Worlds and the Fate of the Earth (which draws on this study), conducted this study with his colleagues in order to address the issue Climate Change in an astrobiological context. As he explained in a University of Rochester press release:

“Astrobiology is the study of life and its possibilities in a planetary context. That includes ‘exo-civilizations’ or what we usually call aliens. If we’re not the universe’s first civilization, that means there are likely to be rules for how the fate of a young civilization like our own progresses.”

Read the rest of the article HERE.

https://www.universetoday.com/139438/does-climate-change-explain-why-we-dont-see-any-aliens-out-there/

Matt is a Science Fiction writer and this article is a sample of his craft.

[George Rebane]

Russ 225pm - We know that such models can be made by the dozen. The weak part of all of them is that there is no science that can reliably predict a planet's temperature (however you measure that) from a few input parameters like population size, energy usage, and mitigation technologies. For example, consider a civilization that gains almost all of its power from nuclear energy vs one that get the same power from burning fossil fuels.

[The Estonian Fox]

I present a dinosaur talk to 7th graders in local middle schools. Two years ago I added a slide with a double graph - top graph shows oxygen in the earth's atmosphere, the bottom one is CO2. But the slides show a slightly longer view of the present atmospheric levels (PAL) - these graphs show levels going back 500 million years. Present CO2 levels are at their lowest levels in the last 500 My. Levels during dino time (230-66 My ago) were higher (800-1200+ ppm) than they are now (400 ppm). (see Daniel H. Rothman, PNAS April 2, 2002, Figure 4). Dinos seemed to thrive throughout the period. So maybe we are not on our last legs.

But why isn't anyone concerned about the O2 levels? They've decreased monotonically from 26% to a PAL of 21% over the last 50 My. (see R.A. Berner 1999, Perspective Atmospheric oxygen over Phanerozoic time). I love to breathe oxygen, and someone is stealing it from me.

[Russ]

[email protected]:49 PM

Not sure which two graphics you were using in class, but here are two very telling graphics, CO2 levels in the past and temperatures over the last 10,000 years.

http://www.geocraft.com/WVFossils/Carboniferous_climate.html

http://jonova.s3.amazonaws.com/graphs/lappi/gisp-last-10000-new.png

The world was warmer with more CO2 in the past and O2 is now increasing.

[Russ]

Correction, O2 peaked and is now decreasing. Why? Increased CO2 encouraged plant growth and plants produce O2.

[The Estonian Fox]

Russ @ 8:01 & 9:58 PM
I interpret your last comment "Increased CO2 encouraged plant growth and plants produce O2" to be that as CO2 increases, one expects O2 to increase also. Yet the source you quote belies that conclusion.

Go to your "http://www.geocraft.com/WVFossils/Carboniferous_climate.html", but click on the link "Compare Oxygen (O2) concentrations" underneath the 1st graph with the Mesozoic shown in orange. The link juxtaposes the CO2 & O2 levels. This composite graph is basically the one that I use. If your statement were true, the O2 increase at 400 Mya should be accompanied by an increasing CO2 level as well. In fact, the opposite occurs. CO2 levels are plunging to zero starting at 400 Mya.

And when O2 levels return to 21% PAL at 250 Mya, the CO2 has increased to around 2000 ppm. So as the O2 rises and falls, CO2 falls & rises. A similar event may be occurring from 140 Mya to now. O2 is rising then falling, while CO2 is again falling to zero. CO2 levels were monotonically decreasing from 140 Mya to now. Based on a sample of 1, the CO2 level is due to increase just as it did at 250 Mya, when humans probably weren't around.