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18 June 2018

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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

EF@06:49 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.

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