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And Now For Something Completely Different: Exoplanets

Instapundit links to an interesting article discussing how many potential planets there are in our galaxy, suggesting that as many as “40% of red dwarf stars may have Earth-sized planets orbiting them that have the right conditions for life.” This strikes me as awful premature, given that I don’t think our species are experts on what constitutes “the right conditions for life.” Most of what we believe about how exactly life came about, why, and under what conditions, is speculation, backed by some experiments that show you can synthesize complex organic molecules in laboratory conditions that mimic the early earth.

In fact, if I had to wager, I’d say that Earth-sized planets that orbit in the habitable zone of stars are remarkably common, but that life is comparatively rare, and intelligent life is extremely rare. Professor Reynolds concludes with one of his trademark “We need interstellar travel. Faster, please!” and I tend to agree we need to figure it out fast, but I’ve always been skeptical of the possibility of this, despite the fact that it’s necessary for man’s long term survival.

For one, there’s an intergalactic speed limit, which is the speed of light. Sure, you can speculate about being able to warp space and time, but even if it’s theoretically possible, we have no idea how to even go about it. That leaves us with traveling at sub-light speeds absent discovery of some new physics we don’t understand currently. The nearest star to ours is about 4 light years. There are about 50 stars within about 16 light years of us. Most of them different types of stars from the sun. The fastest you could reasonably move a craft with foreseeable technology would be about 5 to 10% of the speed of light, making a trip to the nearest star take 40-80 years. You don’t get serious time dilation until you get up to 70% or 80% light speed, and at those speeds, we have no idea how we’d make a ship survive even a micro meteorite collision, let alone how to make the crew survive the radiation they’d be plowing through on their way across the galaxy. The amount of energy involved is also unimaginable. We’re talking exajoules to get to the nearest star, even at a pretty modest speed of 5 to 6% c.

So I’m afraid unless we have a lot of breakthroughs in the next 50 years, we’re hundreds of years away from visiting a nearby star system. I think the only way we’ll even accomplish it is either to figure out how to move our consciousnesses to machines, or alter our genetic makeup to live longer, and be adapted for the high radiation environment of space. If we do make the trip, it’s likely going to be one way, which means we’ll need to improve our ability to observe and analyze exoplanets from here in our solar system, so that if we aim for a target, we know we’ll hit something that supports human life.

And that’s not even mentioning what the life there would do to us once we get there. It’s a tough, tough problem, and I’m just not sure humans are smart enough to pull it off at this point in our evolution.

14 Responses to “And Now For Something Completely Different: Exoplanets”

  1. Mike says:

    Agreed about the rarity of intelligent life. The famous Fermi paradox goes if there is intelligent life out there why isn’t it here? Suppose we took one of those 5% lightspeed spaceships that we could build with technology just a little better than what we have now. We send them to a nearby stars ~10 lightyears away and plant colonies. The colonies grow and eventually build a starships and make more colonies. We thus create an expanding wave of colonies that moves out at a rate of ~10 lightyears per (however long it takes to go from a small colony to building starships). If we take this time as between 500 to 5000 years, we fill up Galaxy (~100,000 ly across) in between 5 and 50 million years. This is fast in geologic timescales and really fast in cosmological timescales. If there is some other intelligent life in the galaxy, and they are even 1% the age of the universe (120 million years) older than us they would have done this a long time ago.

    What’s cool about this is that 5-50 million years is a significant time in evolutionary timescales so our decedents who reach the other side of the galaxy may not be what we know as human. In 50 million years the galaxy may be full of inhabited planets that all have people on them that look to a greater or lesser degree like us and are capable of interbreeding to various degrees. Not at all unlike Star Trek.

    • Alpheus says:

      One potential answer to the Fermi paradox, though, is that it simply isn’t economically feasable, in any way, to move much farther than our solar system; it might not even be feasable to settle our solar system as well!

      We have very active imaginations, which is a good thing–it opens the door for exploring the possibility that we can download our consciousess into machines, or creating nanobots that can explore the galaxy–but our imagination can (and does, technically) outstrip what is possible, either economically or physically.

      It may be physically possible, for example, to develop a brain that would be even more intelligent than ours; it may very well be the case, though, that the effort necessary to produce such a brain will be so expensive, that we never will get around to doing it–assuming that we could even figure out how to do it.

      Space is huge. We’re limited by the laws of physics*. We’re also limited by the resources we have. And every other intelligent form of life will be limited by the exact same constraints.

      Now that I think about it, though, my first sentence–“Space is huge”–may explain alone why other beings might not have found us. It could be that life is just rare enough, that the probability of any two forms of intelligent life–even life that has some ability to explore the galaxy–is close to zero.

      *Which, granted, we aren’t even close to understanding–but whatever those limits are, they will always be with us, even if we don’t understand them.

      • Harold says:

        One potential answer to the Fermi paradox, though, is that it simply isn’t economically feasable, in any way, to move much farther than our solar system

        A good answer, although people and presumably intelligent aliens might do uneconomic things for their own reasons. Heck, if there’s aliens out there, there’s missionary work to be done to bring them the Word of God! (Not a thought original to me; the Vatican has thought about this and more than a few SF plots are based on missionaries doing “uneconomic” things, as they have on Earth.)

        it might not even be feasable to settle our solar system as well!

        That I seriously doubt; we don’t know how much this will be true, but we’re pretty sure at minimum there are plenty of valuable minerals to be had a lot more economically out in space, where you also have different pollution constraints for refining. Imagine, as David Drake has, being able to build tanks with cast iridium armor (I’m just finishing a fairly good book on US WWII tank destroyers). Or using osmium for projectiles (to bring this back to the firearms theme of this blog).

        To finish addressing your points, people who have dreamed about getting out into space imagine that in due course we or any other alien race will construct major engineering works that will be visible from distant planets (although if life is rare enough maybe not distant enough). E.g. want lots of power? Construct a solar power system not too far from the sun. David Friedman, the son of Rose and Milton, when musing about future property rights, has imagined that one of them would be to subtend (cover) a certain amount of the sun (i.e. use up all it provides, like completely damming and using a river).

        And you are very right that “our imagination can (and does, technically) outstrip what is possible, either economically or physically“. WRT to nanotech, I mentioned nuclear technology. Or take fusion power generation; it turns out to be a lot harder than originally thought. Even aneutronic He3 fusion, which has the advantage of not transmuting your reactor, might not be practical to extract energy from (this is the subject of theoretical debate the last time I checked).

        • Alpheus says:

          I base some of my concerns on an article, written by an SF author if I recall correctly, that I have read recently. He makes a very good case that we’re not settling the Moon or Mars any time soon. Indeed, he pointed out that there are certain very uninhabitable places on the Earth that people aren’t settling right now–and when we do send people there, we pay them gobs of hazard pay. He even pointed out that we haven’t settled the Mojave Desert, and aren’t likely to any time soon.

          Of course, I also have to confess: after reading that article, I’ve wondered what it would take to settle a place as hostile to life as the Mojave desert has proven to be. I doing that would probably be a decent stepping stone to settling the Moon or Mars.

          And it may even be possible that non-economic reasons, such as wanting to live a libertarian lifestyle, or even a certain religious one, may push people into these non-hospitable regions…

          • Harold says:

            Well, it’s very unclear either the Moon or Mars make much sense economically, except for the Moon sort of being close. Compare to one or more near Earth asteroids that have exploitable minerals (and water would be nice) and enough mass to shield from solar storms. Once you get out of the Earth’s gravity well getting to and from them is fairly cheap albeit potentially slow (dragging them to L points would help, but then there’s always this problem (the Gundam U.C. future history adopted as background the O’Neil colony concept wholesale as a solution to overpopulation, a major obsession of the ’70s). Heck, in terms of transit (gravity wells) Mars’ moons are more attractive in some ways.

            To address the Mojave Desert, why would someone move there? We can posit economic payoffs for various outer space destinations, but it??? The author sounds like he’s playing the strawman game; I’d rather have people Tiger Team serious proposals such as the asteroid one, or a Moon colony that delivers useful stuff (mass, water, He3, whatever).

            And it may even be possible that non-economic reasons, such as wanting to live a libertarian lifestyle, or even a certain religious one, may push people into these non-hospitable regions…

            Let’s take a great example near and dear to us, the Pilgrims emigrating to the New World, where indeed around half of them died in the first winter. They were religious dissidents from the established British state church and living in the Netherlands at a time where its republic was crumpling under Spanish pressure, not to mention the Thirty Year’s War just getting started next door.

            Both James I, the only ally the Netherlands had, and the local Dutch church were each demanding they be brought under their control. And if Catholic Spain prevailed they’d be the first to be burned as heretics. So moving to an largely unknown and inhospitable location was arguably the best of many bad choices, given that they weren’t willing to abandon their faith.

            Here’s one other damn good reason: putting all our eggs in one basket is very dangerous for the human race. After an extinction event on/to the Earth its value is incalculable. Or just getting enough space infrastructure so that we can see and stop really bad asteroid strikes.

            • Alpheus says:

              The Mojave desert was one example; if I recall correctly, he also gave Antarctica and the sea, and even under the sea as a few more examples. His point was that these are more habitable than the Moon or Mars would be; even though I think it would be fun to move to an asteroid, such a place would be about as habitable as the Moon.

              As I’ve come to think about it, I think attempting to settle the Mojave desert would be useful in preparing to figure out what it would take to settle the Moon. While things would certainly be different (we wouldn’t be making cement in a vacuum, for example), there are certain things, such as attempting to grow plants indoors, that would be useful to learn; and if something goes wrong, it would be easy to return to “civilization”, get some more parts, and start over.

              And it’s also certain that the biggest hurdle to space exploration is leaving the Earth. If only we could find something more economical than chemical propulsion! (Or even just make chemical propulsion more economical…)

              • kfg says:

                “I think attempting to settle the Mojave desert would be useful in preparing to figure out what it would take to settle the Moon.”

                Indeed. The question is why isn’t it being done? The answer is political, not technical. For instance, the very first thing you would have to build is a nuke. The second thing you would do with the nuke is to rape the immediate environment of its resources.

                Biodome failed not because it was an exercise in closed colony.but because it was an exercise in sustainability. Add energy.

        • kfg says:

          “That I seriously doubt; we don’t know how much this will be true, but we’re pretty sure at minimum there are plenty of valuable minerals to be had a lot more economically out in space”

          Bingo! Mars at the very least is a piece of cake. It takes no longer to get there than it took Henry Hudson to get to NY. Boosting mass to Mars is expensive. Boosting it back not so much. And every half baked SF author has known for something like 100 years that the asteroid belt is the mother lode; best exploited from a base on Mars.

  2. Harold says:

    One point I make about the probabilities of life and intelligent life is someone has to be first; that’s my preferred answer to the Fermi paradox (the others are rather ugly).

    As for interstellar travel there’s a clever concept in Engines of Creation (Wikipedia warning: while it seems to be a lot better now after a quick check, not long ago Wikipedia was very hostile to Eric Drexler and his role in and concepts of nanotech.)

    It’s predicated on nanotech to the level where you can “clone” yourself (e.g. be taken apart atom by atom and reassembled at will; issues of souls not considered, although I suppose they might be answered). Anyway, use a Sun pumped laser to accelerate a solar sail based device to that .1c or whatever (an old idea, and Drexler I’ve read came up with his nanotech idea while trying to figure out how to construct ideal solar sails). After the boost is finished, nanomachines reconfigure the device into a linear accelerator and as it zooms through the target solar system it decelerates a very high Gs one or more very small nanotech probes that then make their way to hopefully habitable planets.

    I usually finish my explanation of the concept by saying “At this point, any one of a number of science fiction alien invasion plots will suffice.”

    More specifically, based on info carried and/or transmitted (a big receiver can be part of the infrastructure built in the … colony system), people can be replicated and you have a real colony.

    Or maybe go with the downloading yourself into machines concept; while I’m reminded of the wild pre-Hiroshima speculation in SF of the consequences and potentials of nuclear technology, it’s very possible the only survivors of the development of nanotech will be those who download themselves into hardier survival machines for their “genes” (broadly construed). After all, going from the The Selfish Gene perspective, our bodies are survival machines for our genes.

  3. kfg says:

    Space… is big. Really big. You just won’t believe how vastly hugely mindbogglingly big it is. I’m not sure that any degree of human intelligence can make it any smaller.

  4. Zermoid says:

    It also goes back to the old argument of where would mankind be if we didn’t spend 4000+ years trying to kill each other off with swords and arrows? What if the advances of the last 100 years had been 4000 years ago? And if life evolved on other planets (Which is almost a mathematical certainty) how advanced might it be if it evolved into a peaceful society at an early stage?

    Just because we are stupid and spend most of our energy fighting amongst ourselves doesn’t mean other worlds would do the same if intelligent life evolved there too.

    (I do sometimes wonder if “intelligent” life evolved here either)

    • Alpheus says:

      Of course, it could be that violence is one of the factors that made us so intelligent in the first place. A few months ago I read “Harry Potter and the Methods of Rationality”, and one of the things the author talked about, was “How did we get this big brain in the first place?”

      The author dismissed tool-making, because any tool that is made could be quickly adapted by others with less intelligent minds. His conclusion was that society and politics were what drove our intelligence. He then told a story about how, in a society of chimps, one young chimp (A) helped another (B) to push an old leader out of leadership, and so that B could become leader of the group; shortly after that, the old leader then pushed B out of leadership, so that A could become leader. The author then said a human would have seen that happening a mile away!

      This line of reasoning makes sense to me. After all, if jockying for power, planning a raid, defending your village, and settling for peace are all necessary to survive, then the groups with the better brains are certainly going to prosper!

      So, while it’s easy to say, “if only we had a peaceful society 4000 years ago”, it’s also quite possible that, if we didn’t have a peaceful society 4000 years ago, we wouldn’t have the intelligence to be where we are today.

    • Harold says:

      If you believe to any degree Kuhn’s thesis, grossly and unfairly simplified as “science advances when the old guard dies off and the young whippersnappers can proceed”, then an absence of wars would have been of limited help. E.g. look at how English science and math was held back for a while due to their parochial refusal to use Leibniz’s dy/dx notation in favor of Newton’s dots.

      Then there’s how much war has driven scientific advance; this is certainly true with nuclear technology (and I, helped by many SF authors, can imagine horribly worse introductions of it than Hiroshima and Nagasaki).

      On the other hand, when you look at German contributions, imagine how they were … hindered by the deliberate depolarization of Germany in the Thirty Years War. Absent that, various things might have developed a lot sooner.

      Drawing back to your general point, for all we know conflict is crucial to the development of intelligence. We just don’t know, and the probability of “simple” life evolving into “intelligent” is for me the biggest known unknown in the Fermi paradox.

    • kfg says:

      “where would mankind be if we didn’t spend 4000+ years trying to kill each other off with swords and arrows?”

      In the copper age. The history of metallurgy is the history of weapons.

      “What if the advances of the last 100 years had been 4000 years ago?”

      We were actually on the brink of it more than 2000 years ago. It was principally ideas that prevented it, not warfare.

      “how advanced might it be if it evolved into a peaceful society”

      A peaceful society is, by and large, a contented society.

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