Putting the life back in science fiction


Three solutions to the Fermi Paradox
March 27, 2015, 4:23 pm
Filed under: science fiction, Speculation | Tags: , ,

Wow, didn’t realize I hadn’t posted in so long.  I got busy with life and writing.  Here’s something that I was originally going to put in the book, but it doesn’t really fit there.  It’s thoughts about how human experience might explain the Fermi Paradox.

Now, for one thing, I don’t think it’s much of a paradox.  After all, as XKCD explained in “Alien Astronomers”, it would be almost impossible for a radio telescope on Alpha Centauri to pick up our radio broadcasts.  Military and research radar beams, yes, but not our ordinary chatter.  One critical point is that broadcasting powerful radio signals takes a lot of energy, and that’s expensive.  If it’s more cost effective to be efficient, then we’ll do it (as we have with broadcasting and intercontinental cable) and that makes us more radio-invisible.  At our current level of technology, the galaxy could be brimming with civilizations, and we couldn’t see them, nor could they see us.  Being blind isn’t much of a paradox.

Of course, the question is, why aren’t the aliens here already?  If they’ve had even a million years’ more civilization, shouldn’t they have starships?  Well, here’s another answer: starships are expensive, because at high speeds, they’re a drag.  This came out of an arXiv paper (link), and the pop-sci version on Io9.  The basic point is that for a starship traveling at high speeds runs into photons from the Cosmic Microwave background, and if it’s traveling fast enough, those collisions generate about 2 million joules/second in energy, which seems to act like frictional energy slowing the ship down.  So not only does a starship have to hit those high speeds, it has to continuously generate more thrust as particle collisions slow it down.  You can’t just accelerate a starship and coast to another star, except at really low speeds which would take thousands of years to get between stars.  Do you know how to make a machine that continuously functions for thousands of years?  That’s a non-trivial challenge.  So there’s answer #2 for the Fermi Paradox: space isn’t slick enough to coast.  At high speeds, the CMB acts like an aether and causes friction, requiring continuous acceleration.

Answer #3 for the Fermi paradox is the one I was going to stick in my book, which is about what the Earth will look like if the worst predictions of climate change come to pass, and humans don’t go extinct.  This scenario could also explain the Fermi Paradox.  Basically, in the roughly 500 years of the Industrial Revolution (and yes, I know that it was much longer in the run-up), we’ll have burned through all our fossil fuels, our available radioactive elements, minable elements from aluminum to phosphorus, groundwater, and so forth.  After we use up all the cheap energy and readily available raw materials, we’ll be stuck recycling everything using solar and gravitational energy (or biofuels, PV, wind turbines, and hydropower, if you want mechanisms) for hundreds of thousands to millions of years, until the Earth can generate more fossil fuels. Perhaps we had a brief window in the 1970s when, if we’d gone for it and known what we were doing, we *might* have put a colony on the moon.  Highly unlikely, but possible, and the chances of that colony surviving would be fairly low.  We can’t get to Mars now (due to little problems like radiation in interplanetary space), and if we don’t get nuclear fusion to work real soon now (the 1970s would have been a good time for that breakthrough, too), we’re going to be downsizing civilization pretty radically in the coming century, rather than going to Mars or beyond.

Let’s assume that humans are relatively normal for sapient species, in the sense that we got our rapid spurt of technological advance by using up all the surplus energy that their planetary biosphere had squirreled away for the last 300 million years.  By the time we understood the true state of our world and the galaxy, we also realized we were in trouble, because we were already going into a time of overconsumption and too-rapid population growth. By the time we become technologically sophisticated enough to possibly colonize another planet, we won’t have the resources to do so.  Indeed, we’ll be forced to use any terraforming techniques we work out on the Earth just to keep it habitable.  Once we’ve survived this peak experience, we’ll be a mature civilization (or more likely civilizations), but we’ll also be radio-quiet, highly resource efficient, and totally incapable of interplanetary travel, let alone interstellar voyaging.

That’s the #3 answer to the Fermi Paradox: scientific development marches in tandem with resource extraction, and it’s impossible to become sophisticated enough to colonize another planet without exhausting the resources of the planet you’re on.  It’s possible that the universe is littered with ancient  sophisticated civilizations that have already gone through their peak resource crisis and are quietly going on with their lives, stuck on their planets, kind of like kids who went to college to change the world and got stuck with crushing college debts and jobs that weren’t their dreams.  In our case, we’ve still got a billion years or so left before Earth becomes totally uninhabitable, so it’s not horrible to be “stuck” here, on the one planet we’re evolved to live on. It’s just sad for those of us who thought that Star Trek looked like a really cool way to live.

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9 Comments so far
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So no coasting…sad. Great post! I love this type of stuff. Thanks! – JW

Comment by J.W. Kurtz

When you talk about being stuck with water, wind, and solar power, do you mean old forms like medieval grain grinding machines and architecture designed to be warmed by the sun? I agree that a society that can’t generate electricity is not going to launch things between planets, much less between stars.

If you’re not predicting a coordinated global collapse and permanent loss of knowledge, though, I don’t see how “no more complex industry” or “no more space launches” follows from no more fossil fuels. If people burn all the extractable fossils and have a big nuclear war to cap it off, ok, I can see how the chaos could knock humanity back to the pre-dynamo age and destroy enough knowledge/resources to keep it there. Otherwise…

Solar power is a larger resource than all the world’s fossil and nuclear fuels put together. PV EROEI keeps going up, prices are still falling and manufacturing scale increasing, and you can make modules, racks, and transformers using very abundant materials: silicon, aluminum, iron, and oxygen. It’s very similar for wind. No rare materials required for the equipment, and the places where you can get useful sun or wind energy are far more evenly distributed and common than oil fields or uranium deposits ever were.

There were 92 launches to space in 2014 and that was considered a busy year. Each launch burns maybe a hundred tonnes of liquid fuel. Do that a hundred times a year and it’s a footnote in terms of continental scale energy use, even in a post-fossil-fuel world where every liquid fuel needs to be manufactured from one or more of biomass, water, CO2, and electricity.

I don’t think you get populated interplanetary colonies this way, but I think those are unlikely for lots of reasons. We’d still have weather and communications satellites though, and could still send instruments to examine to the outer planets.

I sound a lot more optimistic in this comment than I mean to, only because I think you are excessively pessimistic. And I rarely think that people are excessively pessimistic! I think the fossil fuel barons are going to keep getting their way long enough to ensure unnecessary misery for thousands of years to come. But there’s still a big gulf between that and permanent catabolic collapse back to 18th century (or older) toolmaking capabilities.

Comment by Matt

Hi Matt,

Actually, I hope you’re right. Without checking, I do know that wind turbines use rare earth magnets and I think that some solar panels use rare earths, so there may be limits based on those elements. Otherwise, it’s a matter of whether there’s enough energy available to do the launch.

If we can’t make solar panels or wind turbines (either because of lack of elements or a breakdown of the international manufacturing system that makes them), energy availability goes sharply down. If you grow sugar cane, you can get about 500 gallons of ethanol/acre/year, although they’re working on “energy cane” to get that up to 1000 gallons of ethanol/acre/year. That sounds like a lot, but that’s about 1 car/acre/year in current fuel terms. Cellulosic ethanol might be more productive in terms of ethanol/acre, but it’s also a lot slower. Wind power without a huge turbine is a lot less productive, and even hydropower can be problematic if there isn’t any snow in the mountains to let water out during the summer.

Comment by Heteromeles

Some wind turbines do use rare earth element magnets. The majority of wind turbines do not. The same goes for electric motors in hybrid and pure electric vehicles, and for rechargeable batteries. I follow solar technology closely and there is not any commercial PV technology in use that needs rare earth elements. Over 90% of the world market for solar PV is based on silicon. Those modules don’t require rare elements at all. The rare (but not rare earth) elements indium and tellurium are used in thin film solar technologies that make up about 7% of the PV market.

There’s a toxic mixture of rare earth urban legends in circulation and posing as wisdom. They seem to be spread by a mixture of 1) people who want to keep burning fossil fuels like usual, so they bang on “everything has problems” and hope people won’t notice the *magnitude* of the respective problems 2) people who want investors in economically marginal junior mining companies, and need a good story about the Rare Earth Apocalypse or Chinese RE Monopolists to sell shares and 3) environmentalists who have seen humans behaving recklessly so many times that they’re willing to believe another piece of bad news without verifying the supporting information.

Comment by Matt

Thanks for the corrections. I’m a little surprised at the wind turbine information, but whichever. The issue may be high end vs. what’s currently in use.

As for rare earths, the issue so far as I’m concerned is getting the darned things, not that they’re horribly dangerous. I’ll be happier when we can recycle them better, but at the same time, it looks like the Chinese do still control the biggest deposits of the ones we tend to use in electronics. The supporting information I’ve seen is a morass of competing claims, so I haven’t really probed into them to try and figure out who (if anyone) is telling the truth right now.

Comment by Heteromeles

Light rare earth elements like cerium, lanthanum, neodymium, and yttrium have good sources outside China. Chinese production underpriced them enough to nearly eliminate those sources for a while, but they are back now. Molycorp has resumed rare earth extraction in Mountain Pass, California for example, after it was shut down for about 10 years due to low priced Chinese competition. Siemens just signed a 10 year deal with Molycorp to supply the neodymium for their wind turbine magnets.

Heavy rare earth elements like holmium, erbium, and dysprosium are still almost exclusively sourced from China. At present China has the world’s best known deposits plus most of the lived experience of recent decades operating the mining processes.

By a vicious game of telephone true statements about specific products have been turned into broad lies. “The Prius uses lanthanum in its batteries” turns into “you can’t make hybrid cars without rare earth elements.” Or “First Solar’s thin film solar modules need tellurium” turns into “the solar industry relies on tellurium.”

Light rare earth elements are used to make catalysts for fuel refining, high strength magnets that don’t need to endure high temperatures (like those in hard drives, audio speakers, stepper motors…), specialty ceramics including solid oxide fuel cells, some kinds of laser crystals, and nickel metal hydride rechargeable batteries.

Heavy rare earth elements are used to make phosphors for fluorescent and white LED lighting, optical amplifiers, other kinds of laser crystals, and high strength magnets that need to endure high temperatures.

The most constrained material of these for clean energy production is dysprosium. It really is pretty rare and its production is still nearly monopolized by China. Dysprosium added to neodymium magnet materials allows high-power motors and generators to operate at high temperatures without losing magnetic strength. Without dysprosium you need a more complex cooling system to keep neodymium magnets from overheating in high power applications. In offshore wind turbines especially you see a trend toward larger generators and minimizing service requirements at the expense of increasing initial equipment costs. Both of these trends are driven by the high cost of working offshore and both of them encourage more expensive, but lower maintenance, large direct drive generator designs incorporating dysprosium-enhanced neodymium magnets. Inside China, where domestic manufacturers have preferential access to mineral resources, direct drive turbines are common for onshore use also.

The latest numbers I can find — a publication in 2014, reporting on 2013 — indicated that 28% of the global wind turbine market used rare earth permanent magnet generators. That share has been increasing over time. The distinguishing terms to look for are “induction generator” vs. “direct drive.” Direct drive indicates powerful permanent magnets which indicates rare earth elements. Induction generators use electromagnets instead of permanent magnets and do not use rare earths.

Good grief that was long.

Comment by Matt

Long, but much appreciated. Thanks.

Comment by Heteromeles

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Seems like the easiest resolution of Fermi’s paradox is that there are no aliens and that’s why we haven’t heard from them.
The belief that there should be aliens is based on a number of assumptions, all of which are taken for granted by most educated people in western society. There is the idea that since the earth has a finite history and that there was no life on it at the beginning, it must have arisen spontaneously at some point from purely physical processes. This is a fairly recent idea. Keep in mind that organic chemistry got its name from the belief that only living organisms could produce organic chemicals. It also implies that the people who named organic chemistry thought that living organisms had a history separate from those of nonliving entities.
Then there is the belief that the universe is fairly homogeneous and that the same laws apply throughout and that therefore we can assume that there are any number of planets out there just like earth that could also originate life through random chemical interactions.
My interest in the topic of artificial life has waned over the years so I am not current on the topic, but last I heard, there is not much known about how life originated on earth. It is assumed to be easy and should therefore happen everywhere in the universe that has earth-like planets. Nevertheless the details are missing and spontaneous generation of living organisms may in fact be more difficult than assumed. It seems that once there are living organisms, their evolution into more complex organisms can begin and is fairly rapid, much more rapid than the initial creation of living organisms.. Nevertheless, first you need something for evolution to work on.
So anyway, all the premises seem reasonable if you are not a religious fundamentalist and so I would also have to go with the idea that the paradox arises from the short lifespan of civilizations.

Comment by Wolfgang Brinck




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