Terraforming Venus; Venus-forming Earth

Terraforming Venus would require taking almost all of the CO2 out of its atmosphere, so it becomes breathable, doesn't crush us (currently 90 atm pressure) and cools the planet down. Using our current mechanical carbon scrubber technology may seem simplistic and unimaginative, but the other options that have been discussed feature similar science-fiction-level ideas (crashing outer solar system ice moons into it, locking carbon into the crust down to a kilometer deep, or getting theoretically present hydrogen out of the mantle.)

This is less likely to happen than being able to move moons around the Solar System. Image from reddit.com/r/mapporn.

Let's make many optimistic assumptions:

That we can build self-replicating independent carbon sequestration plants; this minimizes transport costs and covers the planet.

That they can build and fuel themselves from materials available on the surface of Venus.

That they can withstand conditions on Venus (when the longest any machine we've put down has lasted is on the order of an hour.)

Current carbon sequestration plants are the size of a cargo container, and sequester 900 tons of carbon per year. Assume that this is the rate at which they operate on Venus, and that self-replicating carbon sequesterers are 100x bigger than the real, non-self-replicating ones we have.

Assuming near 100% working replicas, and a one-year self-replication cycle, it would take 40 years to cover the entire surface of Venus with these - after which they would take 2000 years to clean the atmosphere of CO2. (This would still leave a nitrogen atmosphere several times higher pressure than Earth's.)


Venus is not the best candidate for terraforming or habitation, and humans will not settle its surface for thousands of years at least. We should concentrate on terraforming planets in our solar system, building self-replicating technologies, and having humans in isolation from Earth in case of some sort of collapse (most easily, on the Moon.)


On the other hand, here on Earth, just to keep even with carbon emissions at the 2017 level, we would need 40 million of the scrubbers we currently have. That means no matter where you went on Earth, there would be one within less than two and a half miles of you.

We do have machines that are Venus-forming Earth, by making more CO2. They aren't self-replicating, but they seem to have a relationship with one species (unclear if parasitic or symbiotic) and in places they cover the surface just the same.

Timeline of Manned Interstellar Travel, Based on Simple Economics: No Humans on Alpha Centauri Planets Until 2613

It has been estimated that a manned Mars mission would cost $100 billion. Compare this to the most recent unmanned lander, Insight, at $830 million; putting people on Mars then comes with a cost multiplier of 120.

The Initiative for Interstellar Studies estimates that an unmanned interstellar mission would cost at least "in the trillions"; Centauri Dreams cites Odenwald at $174 trillion. Assuming the same scaling, the lower and upper bounds on that then suggest that a manned mission would cost from $240 trillion to $21 quadrillion.

If on the other hand we take the projected cost of a manned mission to Mars, and assume it scales linearly with distance, a manned Mission to Alpha Centauri would cost $55 quadrillion.

It's worth pointing out here that world GDP is $80 trillion. Let's assume an annual economic growth rate over time of 2%. Let's also assume that starting tomorrow we put ALL of GDP toward such a mission - that is, every last human is working this mission and just barely otherwise just barely surviving as peasants eating crumbs.

Assuming an annual economic growth rate over time of 2%, then at earliest, we can launch a manned interstellar mission at the earliest by 2227; at latest, by 2501.

But forget about that. Because neither you, nor any other human on this planet will sign up tomorrow for their descendants being reduced to slavery for centuries for a space mission, which is what those numbers assume. So let's assume we continue to spend money on space exploration at the same rate that we in the US currently are - about 0.11% of GDP. This is already quite a generous assumption, given that most countries can't afford to dedicate such a fraction of wealth to endeavors that don't quickly return on investment. If you're more optimistic and want to set the relative rate of expenditure (over centuries) to the highest it has ever been (in a democracy - you said you were optimistic right?) that's 1966 USA, which is about twice what it is today, and only makes it happen 35 years earlier. (This is more dependent on economic growth than space program expenditure.) So let's stick with current NASA budget fraction, and assume that the future space program is ONLY working on this one mission.

By these assumptions, we can launch the mission at earliest by 2570; for the upper bound estimate, by 2845.

Our fastest spacecraft so far would take another 30,000 years after launch to get there. Let's be more optimistic and assume that the light sail technology we're talking about for unmanned probes also applies to manned craft, and can get the ship up to 10% of the speed of light. Therefore, taking into account travel time and speed-of-light delays, we wiill get the interstellar "Eagle has landed message" at an absolute cheapest earliest date of 2618.

Of course this is still unrealistic, because we're still assuming mission development starts in earnest tomorrow, assuming every government on Earth will let us use a NASA-sized fraction of their GDP for this, and that they will continue to cooperate for at least 550 years building the mission. Think of this in reverse: it's as if in 1470, the middle of the War of the Roses, and the Russians and Poles and Lithuanians still throwing off the Mongol yolk, everyone started spending money and cooperating on a project and continued to cooperate on it until this year.

I think it is unlikely, barring unforeseeable scientific revolutions, that human beings will leave the Solar System this millennium. I think it is likely that there will be civilization or species-threatening or destroying events in this millennium. This discussion of colonizing other planets to mitigate existential risks has a scatter plot listing a probability of event happening within 200 years/risk of civilizational collapse for nuclear war, coronal mass event, rogue AI, and nuclear war as 90%/20%, 70%/90%, and 95%/70%.

Using those same numbers, in the time period until launch there's a greater than a 96.6% chance of a rogue AI, and a greater than 99% chance of coronal mass event or nuclear war.

But fully automated probes could get out more quickly, particularly if we design self-reproducing von Neumann probes. We should start terraforming Mars now, as practice for remotely terraforming planets with von Neumann probes for when we eventually get there. We have time to terraform them, because if physical human bodies ever do get there, it will be in the distant future. But we do not have that much time to get the launch the hardware, which suggests we should at least colonize the Moon as insurance. Cryonics and hibernation technology at this point is still basically science fiction. These numbers are depressing given our previous dreams, but we calibrated on going from powered flight to standing on the moon in 2/3 of a century.

CNS Damage in Mice Experiencing Mars-Voyage-Like Radiation for Six Months

This is not good news. We should expect that humans undergoing a Mars trip, with selectively vulnerable hippocampi and dependent on complex behaviors for survival, will fare even worse per unit time, and worse still over the closer to twenty-four months for the out and back that such a trip would take. Regardless of air, water and food requirements, this is yet another barrier to even colonizing the rest of our own solar system, much less getting to another star, and another reason why we might never see interstellar civilizations composed of planetary-surface-evolved organisms rather than machines. Paper here, summary here.

China Sends Astronauts to Its Own Space Station

Three astronauts have arrived at Tiangong-1. I'm amazed at how little media attention this event has received in the West.

Are People Less Likely to Become Colonists Now?

As compared to a few centuries ago? Certainly. Humans in general today are less likely to strike out to a new land and become colonists. Why is this?

(This is cross-posted to my science fiction and fact blog, The Late Enlightenment.)

1. The environments that are available to us are harsher. Seasteading? The Antarctic? The Moon or Mars? Come on, do you really want to live in any of those places? Sure, Virginia may have had a bit more malaria than England but it has a) solid ground, b) it never drops below -50 C and c) it has a 21% O2 atmosphere. Consequently, it takes a more complex and developed economy to allow survival in the harsher land. And even Jamestown wasn't self-sustaining until the third ship full of people and supplies arrived. (More on Jamestown and Mars here.) And think: how big would a colony in Antarctica have to be in order to be self-sufficient, and make all the equipment they need to survive, not to mention to trade with the rest of the world? (See below for places that are much more amenable to humans than Antarctica and frontiers ripe for settlement right now, but somehow are still not filling up with colonists, in some cases despite the local government's attempt to draw them.)

2. There is a bigger skills gap between the median person and what a colonist needs to know. Even if a new island appeared above the ocean and had a nice temperate climate, few of us (especially in the developed world) would be able to take advantage of it. In Jamestown, people plowed and planted fields, hunted, chopped wood, and built small structures. That's pretty much what they were doing at home except for the building part. Even in the developing world, the gap between the skillsets required of someone living day-to-day versus what they would need to do in a terra nova is much wider than what the settlers of the New World faced, or the Polynesians that expanded across the Pacific. And the hunter-gatherers who crossed the land bridge from Siberia to North America almost certainly didn't even know they were on a new continent (and why would they have cared?)

3. We're just more comfortable. Yes, there are still people in desperate poverty, but not as many of us three centuries ago. The median human is much happier, and if they move, they have more information about which countries offer better opportunities, rather than helping to build a country from scratch.


The exceptions I alluded to above are Siberia and the Canadian interior and the Australian Outback. That's a significant chunk of the Earth's land surface. Seriously, if you think that there is no more wilderness and no more frontiers, just buy a few coats and a hunting rifle and move to the Yukon. West Australia is the size of America's Western and Pacific time zones combined and has a population of 2 million, 1.5 million of which are in one city, and at least near the coast a Mediterranean climate quite like California's, and massive mineral wealth to boot - and even with all that, the Australian government has been desperately and unsuccessfully trying to get people to settle it. In any of these places you can quite easily meet Daniel Boone's requirement of refusing to live anywhere that you can see the smoke from your neighbor's chimney. But you won't do this, despite any belly-aching you might have done along these lines. Why not? Because you have a good life already and you have no idea how to hunt, that's why.

Starship Century Symposium UCSD

With Gregory Benford, David Brin, and others. At Atkinson Hall, UCSD. More information here.

NASA Trailer to Run Before New Star Trek Movie

Successfully crowdfunded too. Pretty cool. Especially because of the narrator.

Relativity Engine? Probably Not, But Here It Is Anyway

It's probably science fiction in the service of securing funding (also known as bullshit) rather than science.  Still, here's a story on a Chinese team's claim to have built a microwave relativity engine.

Asteroid Mining and Detecting Others' von Neumann Probes

With the announcement of "firefly", 3D-printing spacecraft to mine asteroids, we're getting closer to exploring space with multiple smaller craft, as well as more immediately economically rewarding activities, which is what will drive space exploration faster.



Of course it's also exciting because I think exploration of low-gravity bodies will give us more information about life elsewhere in the universe than we expect it to. While reasoning about extraterrestrial life invariably means making assumptions we don't even know we're making, based on what we know about the evolution of life on Earth and the number of planets in the rest of the universe, the development of some kind of replicators outside the solar system seems overwhelmingly likely. If we think at least partly self-reproducing probes are possible - and notice above that investors right here on 2013 Earth are trying to convince people they are - then we might be better off trying to get information about extraterrestrial life from artifacts already here in the solar system than from signals.

It is also likely that lower gravity bodies are better for any entity that wants to continue spreading, since gravity wells are energetically expensive to get in and out of. If you can get matter without descending onto a high gravity surface, you should. (Yes, "but what if aliens have antigravity" - but if we're going to bother thinking about it, we have to make guesses with what we know now. Otherwise maybe they'll ride unicorns. More seriously, if they don't care about gravity, why would they waste time with small gravity bodies like Earth? Mine the cores of gas giants. Hide just outside event horizons to evade detection.)

I've given previously in detail my arguments for why these artifacts might already be here, and where we might look. Comets and asteroids was the answer, so of course I'm excited that these mining probes may explore a number of asteroids during my lifetime. If there's something obvious, excellent (and frightening).

If they don't find anything it could mean:

1. There's really nothing there to find. Intelligent life is much rarer than we think. Replicator chemistry is either not as inevitable as it seems, or there's a Great Filter between algae and interstellar expansion, or life is just rare enough that we're isolated.

OR

2. Something is there to find, but we don't notice it at first.

Because we're looking for something alien - something completely outside our experience - it's hard to say what a gas chromatograph of chewed-up alien von Neumann probe chemistry would look like. (This is why I hope full rocks are towed back, so we can have people in Earth orbit doing real chemistry on them.)

So how to distinguish 1 from 2? Keep looking, and follow up any interesting chemistry we find, "interesting" meaning any low-entropy repeating patterns, either temporally or spatially, on low-gravity bodies. I very much doubt we're going to find a metal ship crouching amidst a flying rubble pile. I do think we'll find strange chemistry that's worth looking into, at least insofar as it's relevant to the origin of life on Earth, and at least with comets that's no longer controversial. I haven't yet seen a model which examines what fraction of asteroids we would expect to be colonized by theoretical replicators, so I'm not sure at what rate I should de-weight my expectation of finding alien artifacts on asteroids, as more asteroids are mined without the merest

How Many Voyagers Could We Launch?

From the start of project in 1972 through the Neptune encounter, the Voyager program (2 spacecraft) cost $865 million.  Adjusting for inflation and rounding up to the nearest billion since there has been ongoing activity, that comes to $5 billion a pair in today's dollars.

Voyager 1 will be officially cracking through the heliopause anytime now, at latest by 2015.  It's our first inerstellar spacecraft.  If we wanted to build and launch an army of small spacecraft, how much would it cost?  Using these numbers as our back-of-the-envelope starting point, the theoretical upper limit with these numbers is to look at world GDP, which nominally is $70 trillion.  We'll still need to eat, so let's only use half the world's economic output.  $35 trillion is 14,000 spacecraft.  (Excessive?  Half a percent is still 140 a year.)  We can build ion engines on the cheap once there's a plant in space; the cost remains getting them out of the gravity well we live in.  Orbital drydock would fix some of that.

Next: Hang-Gliding From Space

For many of us part of the fascination for sending balloons into space, and parachuting from it, is the proximity of such an exotic realm to our own world, and its accessibility, in some ways, with pretty mundane equipment. That's why personal space balloon launches are cool. (I wonder if the Peep they sent up with this one was still frozen when it came back down.)

And that's why this article on early Soviet space-jumpers was interesting, and why it seems strange that when astronauts come back down from the space station, the first thing they see is Kazakh steppe grass outside their window, and maybe a distant animal herd. More morbidly, that's why the sole of a shoe making it down from orbit separately, on its own during the 2003 space shuttle tragedy seems strange. This shoe made it from space? To the parking lot of a pharmacy? On its own? (It turns out that C. elegans worms survived it.) Even though a mere 20 miles above us the sky is black in daytime and you can see the curve of the Earth, 20 miles across the surface is closer than many of our commutes.

Inspired by this, I was curious whether soft-body gliders had ever been considered by NASA, in addition to the hard-body gliders and parachutes we now use. In the early 1960s glider technology was extensively tested but NASA went with an all-parachute descent. The Paresev glider is actually on display in the Smithsonian but I guess I wasn't paying attention.



If Baumgartner won't do it, then I wonder if Jokke Sommer could make a few phone calls to the usual crew of Branson, Rutan et al.

Fermi's Warning: Problems in Interstellar Exploration and Detection

[I have an article on the Singularity coming up at the European science/fiction magazine Concatenation in a couple months. Please visit their website ahead of time!]

With the discovery of planets around Alpha Centauri, the time for serious discussion of interstellar exploration has arrived. (And it's been going on in earnest for a while now.) Of course, the people who launch the probes will know they can't possibly see the up-close pictures of any extrasolar planets in their lifetimes. But if we're willing to set aside money in endowments to compound interest for the sake of future generations, why not do the same with long-term space travel?

A sensible approach is to send multiple small probes that behave as a network. Even if they can't reproduce, and even if they can't repair each other to some degree, this is superior to putting all your hopes into one object moving at relativistic speeds in unknown domains. It would be bad if, after millennia of waiting, your single big ship hit a comet in Alpha Centauri's Oort cloud. This is the proposal of Allen Tough and is being realized through a Cornell-initiated project now funded by KickStarter. Landers are a tougher problem, particularly on planets with thin atmospheres where we can't use high effectiveness-to-mass technologies like parachutes to slow the descent.

A Sprite chip-sat.
Human missions are much more difficult engineering problems - either of engineering the vehicles, or engineering the humans inside them. The problem of how to get humans to another star is likely to take much longer to solve than how to get unmanned spacecraft to another star. At the same time, keeping our eggs in different baskets is a good survival strategy for the long term, but that's no reason not to send machines out ahead of us.

At the same time, it's possible that if we reach other worlds similar to the one where we evolved, life (intelligent or otherwise) may already be there, and this may impact on our survival also. Consequently any program of interstellar exploration must be part of a program which acknowledges the very frightening implications of the Fermi paradox and also how to detect intelligent life, if it exists. At all costs we should avoid detection, the results of which which may be another answer to the Fermi paradox (i.e. that the Drake Equation should contain a term for predation.)

Consequently, here's a brief summary of some problems in interstellar colonization and interstellar evolution. Surprisingly, I haven't found an argument map for the Fermi paradox, the Singularity and related arguments, which is what I was initially planning to use as a figure.


1. Whatever path we take to the stars, it will likely be one that yields profit in the near term. Interstellar exploration cannot do this, and will have to be borne on the backs of ventures that produce a return for the investors and/or citizens involved, like (possibly) asteroid mining.


2. The Fermi paradox is likely to be solved by one of two things: we are alone at least in terms of intelligent life (i.e., there is a great filter in front of us) or because they exist, but we don't know what we're looking for or at. This latter option complicates things and makes the universe seem more dangerous.


3. To find places that may be useful to us and/or alien life - assuming complex replicators made of matter (will we even recognize complex replicators that aren't?) we may also assume the following are more likely than not, and constrain our search accordingly:

3a. We should look where there is more matter, and more mature stars (longer for life to evolve and expand beyond its home world). This means to look inward toward the galactic center. On Earth, evolutionary innovation comes from the equator and expands north, for a similar reason: more energy into the system, more liquid water, and more evolutionary innovation. A similar principle may describe the distribution and migration of life in a spiral galaxy.

3b. Look for places with the best reaction media to produce replicators. Standing liquid makes the emergence of replicators more likely because you're creating an environment that favors the rapid interaction of molecules. Water is an especially good solvent because of the number of combinations it allows. This isn't an aqueous-carbon chauvenist argument - if there are other environments that allow replicator building-blocks to interact more rapidly and richly, then those environments will be better places to look for life than places with water.


Basis for aqueous chauvenism: it doesn't have to be a planet-wide ocean, but we don't know of any reaction media that encourage diverse chemistry as well as water.

3c. Suspect life in proportion to reaction volume. If we're talking about water, this means more surface area, and more depth. As origin zones, possibly liquid-water-bearing super-Earths are then more likely to originate life than small worlds.

3d. Look for places with a good reaction medium as in 3b, but with low gravity. This directly conflicts with 3c, but low-gravity bodies with water would be good places for life to spread to (i.e. Enceladus) because of the economics of shallow vs. deep gravity wells. A watery moon of a warm gas giant would be even better. In this sense, super-Earths are interstellar East Africas; places like Enceladus are an interstellar Polynesia. (Admittedly intra-Earth colonization is a dangerous analogy in this discussion.)


4. We should look for artifacts at least as much as signals. Artifacts may be easier to recognize as extrasolar better than artificial signals; and, if some form of interstellar colonization is possible, or at least exploration, we should expect to find artifacts in our own solar system already, unless we think we're the first or are somehow amazingly lucky. The presence of artifacts is also a better test for te possibility of interstellar travel than signals. If von Neumann probes are possible (or "space algae", if we can tell the difference) we should look for evidence on small bodies in the solar system, again because of the economics of gravity wells. If we don't find evidence of artifacts once we've explored even a fraction on any low-gravity bodies, and von Neumann probes are possible, then the possibility of life or its artifacts expanding beyond its home solar system is de-valued significantly. (I would put this on Long Bets but at the rate of current exploration, don't think the question will be settled in my lifetime of maybe half a century more.)


5. I've already made many huge assumptions here, and I'm being more conservative than most. It bears keeping in mind that we have N=1 and we don't know what we're looking for or at.

Intelligence Itself as the Great Filter

[I have an article on the Singularity coming up at the European science/fiction magazine Concatenation in a couple months. Please visit their website ahead of time!]

I referred to the Great Filter in an earlier post.  This is the idea that the great silence the Fermi paradox seeks to explain is not illusory:  we really are alone.  If that is the case, then since we know of one example of life and intelligence which did evolve, there must some event or set of events that dramatically decreases the odds of life evolving, becoming intelligent, and spreading from its home or at least signalling its presence.  By self-indication arguments, we can assume that many other species have achieved a level of intelligence similar to our own, but that something must have happened afterward to keep them from persisting or expanding.  This means it is also likely that the filter is still in front of us, i.e. that we will go extinct or at least be permanently confined to our solar system.  I'm increasingly unable to discount the idea that intelligence itself is probably, usually, an evolutionary dead end. 

The less interesting version of this idea is that given the way evolution works, intelligence is invariably layered on top of older systems like emotions and appetites, which were previously constrained by the limits of their behavior but once amplified by intelligence quickly destroy the surrounding ecosystem.  (Essentially, the Special Agent Smith argument, but stripped of misanthropic moralizing.)

The more interesting version is that once a self-aware entity understands that pleasure and survival are separable - i.e., that its survival signal is not the same as its actual survival - and has the means to manipulate the former intentionally (ie full simulation and/or goal manipulation, which are the ultimate ends of heroin, pornography, and ideology) then the end is close.  This is a much more pessimistic version of involution.  Singularities could be thought of as either of these - a form of ecologic degradation that doesn't result in interstellar colonization, or as an opportunity to dissolve into fantasy worlds.

Finally, it could just be that it's incredibly unlikely that any life which evolves from matter, at the bottom of a gravity well, with a life-cycle inextricable from such an environment (needing an atmosphere, solvent, a complex web of other replicators), simply cannot expect to expand across a universe where even inside the comparatively cluttered galaxies the possible new homes are separated by light years.  To a first approximation, the universe is made of vacuum with some dark matter.  It may be then that every star is surrounded by an insurmountable Wallace Line.

Summary of Actual, Current Starship Designs

From Popular Mechanics here.

How to Build an Interstellar Ship

This piece focuses on the here-and-now urban ecology applications that could help drive the development of interstellar-travel-oriented biotechnology. This is smart because a nearer-term payoff dramatically helps to move technology like this forward, and it's why the recent asteroid mining proposal is exciting (though there hasn't been a lot of discussion since the initial press release).

Another possibility, if not for interstellar travel, then for colonizing Mars - settling Antarctica sustainably.



You think that's inhospitable? Seriously? Then you don't even want to see Mars. That's all water laying around. Plus there's air. And Antarctic settlements wouldn't last two years once the supply lines shut down.

Improvement on Alcubierre Warp Drive

Reported here in the popular press, and actually being prepared for an experiment. Background here.

Vandenberg Launch Now Scheduled 14:39 Pac Time Thurs 13 Sept.

And I'm not holding my breath for that one either.  Too bad it's during the day.

Send Ships to Space With Nuclear Bombs

It was called Project Orion - documentary here.  There was actual U.S. Federal research money spent on this.  If you've ever read the Niven-Pournelle novel Footfall you've heard of this before.  (Thanks to Kevin for the tip on the documentary.)

Vandenberg Launch 0027 Friday 3 August

The launch of the NROL-36 payload (a spy satellite) was delayed 1 day. This means it will be launched Thursday night/Friday morning at 12:27 a.m. I've seen a launch from just outside Vandenberg but I want to see if it's visible from San Diego - it's 230 air miles but it should be, since these launches are usually visible from San Francisco which is further. Vandenberg launch schedule here. Beware sudden-onset fog at the coast! If this hadn't been delayed, I would have missed it last night for exactly that reason.

  Atlas V launch from Cape Canaveral earlier in 2012.  Skip to 2m20s for the liftoff.

Method to Spot Relativistic Interstellar Travelers

Look for unique characteristics of light reflected off relativistic objects, modeled by three physicists.

Several years ago, arguing by analogy with supersonic objects, another physicist made an argument that gamma ray bursts and double radio sources associated with galactic nuclei have a lot of the characteristics you would expect from a superluminal object.