Putting the life back in science fiction


Silly summer thoughts 3: Dune Shields

First, a bit of news: I’ve got another guest post up on Antipope, if you haven’t already seen it.  Go have fun with it, if it’s your sort of thing.

Now back to summer silliness; why not pick on Dune again?  It’s a fun target at the moment, especially since it gives this distorted impression that magnates and aristocrats could be part of  a breeding project to produce a superhuman messiah, even though rationally we know that regression to the mean seems to be a more common outcome for human reproduction(except for inbreeding, which gets rather worse).  The current administration in Washington is a great example of how each generation in a wealthy family gets smarter and more talented.  Or not.

In any case, for summer silliness, I give you the shields of the Dune universe, which apparently are spherical shells of force (or weirder, if you’re David Lynch and filming the novel), that slow down objects passing through them to 6 to 9 centimeters per second (this from the glossary in the original story and here) . Continue reading

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Silly summer thoughts, Part 1: new Dune movie

Just a brief one.  I recalled today that a new adaptation of Dune is currently in the works, random deities help us.  I’m not a huge fan of the series, but I did like the original Dune, for what it’s worth.  It’s gotten rather more humorous as I found that Frank Herbert’s idea of a dune was based more on his coastal Oregon dunes than on the Sahara, that his idea for the sandworms came from maggots eating a mushroom, and the Bene Gesserit and their blue eyes were, erm, inspired by his ingestion of (hopefully) non-wormy mushrooms.  Those were the days.

Thing is, I’m a grumpy ecologist.  I’m still trying to figure out how you get their metabolism to effectively run backwards so that they exhale/fart oxygen (I guess they breathe in CO2?).  And a sandworm hundreds of meters long snacking down on a human is about as close in optimal foraging strategy as humans chasing after individual ants.  Ant hives, yes, but individual ants?  Anteaters don’t bother with them, and sandworms shouldn’t bother with individual humans thumping across the dunes.

Still, I wanted to have a little fun, it being a hot afternoon in July.  So I started thinking about those still-suits, which capture and filter sweat and urine and recycle is so that the wearer can drink it again.  Talk about a sweat bath!  If you’re wearing one of these damned contraptions, you’re going to get heat stroke in short order, unless there’s some mechanism for getting the heat out of the recycling body fluids and off into the air.  I may be wrong, but I think that takes energy?  And aren’t electrical signals supposed to attract sandworms? Continue reading



James Schmitz’ Botanical Godzillas
October 17, 2016, 2:57 am
Filed under: science fiction, Speculation, Worldbuilding | Tags:

Up from the depths, sixty stories high…

This is just a little note, spun off again from a discussion on Antipope.  The idea we were pitching around was whether a pelagic floating forest was possible on Earth.  I explained there (and will here) why it would be difficult here.  Still, I know of three floating forests in the science fiction literature: as a minor scene in Dan Simmons Hyperion, as the raft trees in Joan Slonczewski’s A Door Into Ocean, and last (or first, and arguably biggest) as the floatwood forest/trees in James Schmitz’s The Demon Breed.  Oh, and there’s the slightly more realistic example of Prof. Mark McMenamin’s idea of a far future floating mangrove that kicked up in a long-ago issue of Discover.  There is at least one other idea that’s not worth going into here (don’t open this link).

And yes, I like floating forests, and they were very much in my mind when I wrote that first Scion of the Zodiac so long ago.  I really will have to rework that some day.  Anyway, the point here is to go into why a floating forest might work biologically, but why it’s hard to get there from here, for reasons that aren’t obvious to a non-botanist (or even to most botanists–I’m a bit of a magpie).

I was curious, so I reread The Demon Breed after the discussion on Antipope, and I can now see the problems in the story I enjoyed so much before.  The floatwood tree is probably a kilometer or miles across up to six hundred feet tall, built like an atoll with a central lagoon underlain by giant call them rhizomes.  It’s a wonderfully exotic environment, so big that a hurricane doesn’t particularly shake it.

The first problem with it is the height.  On Earth, the tallest theoretical height for a tree is between 400 and 426 feet (reference).  It’s determined by a bunch of forces: the force of gravity, the ability of a tree to balance photosynthesis (sugar going in) with respiration (sugar going out), and capillary action, which is the force that sucks water from the roots up into the leaves.  That water is held under tremendous tension inside the vessels of the tree, and if the column breaks and a sucks a gas bubble out of solution, that’s the end of water conducting nutrients up out of the roots.  Redwoods get about as tall as it’s possible for any tree to get, and the ones that get that big tend to basically have their roots in creeks.  To do this, a redwood is basically a column.  In contrast, floatwood trees are twisting canopies six hundred feet tall.  This is basically several times too big to exist and support itself through photosynthesis.  Indeed, redwoods only pull off the trick because they live where it’s relatively cool and very wet.  The cooler temperatures limit their respiration rates.  In the tropics, it’s tricky for a tree to get that big, because it’s respiration rate is much higher.

Then there’s physics.  The biggest wooden boat in the world is a lot smaller (reference), and the reason is that huge wooden boats aren’t particularly stable, any more than huge wooden buildings are.  Wood’s not the strongest construction material to build a floating atoll out of.

I can go on, but Schmitz’s floatwood forest is a botanical godzilla, rising out of the ocean, but too big to exist.  So sad, but a fun story nonetheless.  Now, let’s go into what you need to build a floating forest.

First off, don’t make it so gynormous that it is hurricane proof.  Better that it can be broken apart  in those 50 foot waves and regenerate from the pieces.

Second, it needs to be light enough to float.  Kelp does this quite nicely, but it doesn’t pop above the surface.  Normally, trees are big so that they can compete successfully for light with smaller plants.  In the deep ocean, the only reason to be a tree is to be a nutrient magnet.  If the raft tree can be a home for birds and other amphibious pelagic species, their wastes can feed the tree.  Coral reefs use a similar trick to grow so immense in nutrient-poor tropical seas.   So the raft tree doesn’t need to be just a float, it needs to have light enough rhizomes to float trunks above water, plus various waste materials left by the critters it’s trying to attract.  Something the density of balsa would work nicely, but then again, balsas are a conventionally built tree that don’t tolerate saltwater, so they’re we’re not going to see oceanic balsa trees anytime soon.

There are, in fact, floating aquatic plants: water hyancinth, wolfia, and friends (all fairly closely related).  The ferns Salvinia and Azolla, and various rushes and grasses (such as papyrus.  Oh, and sphagnum moss, which can make floating bogs wherein trees grow.  These are all freshwater plants that grow in still or slow-moving water.  Aside from sphagnum, all of them grow in nutrient-rich waters too, which allows them to cheat.  Sphagnum does its own weird thing that sequesters nutrients with polyuranic acids, and make it really hard for any but specialist plants to grow in bogs.   I’m pretty sure peat moss (sphagnum and friends) is not structurally stable enough to stand up to oceanic waves, even though it can hold small trees. So this is a dead end too.

Then there’s nutrient capture.  If the rhizome floats are underwater, the plant doesn’t need to have a big root system for taking up water.  Indeed, roots hanging down are basically fish food unless they’re covered by some protective symbiont.  It’s better to have a poorly developed root system and take up water through rhizomes.  Still, the plant will need adventitious roots inside the crap that it’s accumulated, so it needs a crap accumulation structure.  Bromeliads do this best, but so do staghorn ferns and other epiphytes.  In general, these are modified leaves that collect junk in their basket-like modified leaf bases, then send roots (or for bromeliads, modified hairs) into the resulting compost to get nutrients to grow.  Again, none of these epiphytes are salt tolerant, so they’re not going into the ocean either.

There are salt tolerant plants in three places: deserts, beaches, and salt marshes.  Deserts and beaches often have similar plants, because they’re very similar environments (this is true in California.  In the tropics, it’s a different matter, and atolls are the kind of oceanic, nutrient-poor environments that might give rise to a floating plant, except that beach plants aren’t normally that aquatic.

Salt marsh plants are aquatic and salt tolerant.  Their problem is that salt marshes have a lot of nutrients in them.  Indeed, they often capture sediments upstream of where coral reefs are located, and they’re an integral part of the greater reef systems.   While salt marsh plants could conceivably become pelagic floaters, the problem is that they’re going from a nutrient rich to a nutrient poor environment, and these take different adaptations.

You’re beginning to see the problem, I hope?  A raft tree on Earth is a chimera, with the salt tolerance of a beach plant, the flotation capacity of a balsa or giant papyrus, the nutrient capturing capability of a bromeliad, and so on.  No one plant lineage has all the traits that a raft tree would need to evolve from.  To get there from here, you need to come up with a scenario wherein some plant acquires one trait after another, making it successful as a land-based or amphibious plant, before going on to become fully pelagic.  It’s not impossible, but it is tricky and counterintuitive.

This doesn’t mean that such a plant couldn’t evolve on another planet.  If it was, though, coastal swamps, rivers, and beaches would be covered with ecosystems that are much more complex than the coastal ecosystems we know on Earth.  If, in the far future, plants were to take to the surface of the ocean, we’d expect the same complexification of coastal and wetland ecosystems as well.

There are a couple of points here.  One is that botanical chimeras are just as chimerical as animals are.  If you’re going to get grumpy about giving cats horns, you need to be grumpy about giving eudicot trees some structures from monocots and ferns.  The second is that nothing happens in a vacuum, so if you want an alien biosphere that produces, say, floating forests, this is going to litter that biosphere with relatives that either aren’t floating or aren’t in forests.  That’s something that all to seldom shows up in science fiction.



High tech, no antibiotics: a thought experiment
September 24, 2016, 8:39 pm
Filed under: futurism, science fiction, Speculation, Uncategorized | Tags: , ,

First off, I wanted to share a neat video from Bad Astronomy, showing just how, and how fast, bacteria evolve.  Yes, this is evolution in action, captured on a video.  Share it with your creationist frenemies.  Isn’t the 21st Century awesome?

And now, a thought experiment: normally, when we think of a science fictional future, it contains antibiotics, either explicitly or more generally, implicitly.  Antibiotics are routine, not just for treating infections, but more importantly for treating wounds such as you would get from surgery.  Anything involving a transplant, a replacement, or even opening up the body goes much better if there’s a course of antibiotics afterwards to clear up whatever bacteria got into the wounds that the surgeons made.

It’s not news that antibiotics are ephemeral products, and that the more we use them, the faster they become ineffective.  They knew that when they commercialized penicillin.  My question is, what would an antibiotic-free future look like?  Especially one that is high-tech? Continue reading



And We Thought Hibernation Was Simple 2: now with bleach

Most of a year ago, I posted about the first tardigrade genome sequence, which apparently had a lot of bacterial genes in it.  Now, another group has published another genome (io9 article here, report here), and this apparently changes everything, possibly in a better way.  Or possibly, we’ll see some horror move remake of The Fly, only with Ramazzottius varieornatus at the hybridizing end (paging John Scalzi.  I’ve got your vacuum-sucking warriors right here). Continue reading



The dust of ages

I came across this little bit when listening to NPR’s On The Media.  The episode is entitled “Digital Dark Age” which of course pricked my ears up immediately, as the digital dark age is something I dealt with in Hot Earth DreamsThe whole hour is worth listening to, but the weird idea I wanted to focus on is the idea of using artificially generated DNA for long-term data storage, an idea put forward by Dr. Nate Goldman in this segment.

Superficially, this is a great idea. Dr. Goldman is working on this idea as a way to store the huge amount of genomics data he has to curate at the European Bioinformatics Institute.  DNA is pretty stable and information dense, so if it’s possible to cheaply generate long DNA sequences and to cheaply read them, it’s a good form of ROM (Read Only Memory).  Dr. Goldman develops this into an idea of caching the great works of civilization in some sort of time capsule that starts by explaining what DNA is and how the code works, then progresses to simple decoding examples, and finally to the whole earth encyclopedia, or whatever is supposed to be in the data cache.  DNA is certainly more durable than known electronic digital media and is smaller than durable analog media like baked clay tablets, so superficially it has a lot going for it.

One little problem with this scenario is the idea that it’s easy to generate and read DNA.  It’s easy now, but I remember how hard it was even 20 years ago when I was in grad school.  This is a new technology.  Indeed, Dr. Goldman doesn’t think this technology will be financially viable for another decade or two, although it’s borderline technologically viable now.

Still, DNA ROM works better if we’re talking about a hypothetical sustainable civilization, as opposed to leaving some sort of time capsule for the next civilization 5,000 years from now or whenever.  DNA is not the kind of storage medium that will allow people to jump-start civilization from a hidden cache.  It’s just too tricky to read and write, even though DNA has demonstrably lasted tens of thousands of years in fossil bones under ideal conditions.

It’s even more suitable when we’re talking about interstellar colonization, where information needs to be stable for thousands of years.   Not only can the genomes of potentially useful organisms be stored as DNA, all the other information the starship needs to curate can be stored as DNA as well.

The other little problem with using DNA to store data is that having such technology widely available means that high-level synthetic biology will be available to anybody who wants it.  After all, if the equivalent of a laptop can generate as much DNA as your average genome, how many more bits of equipment are needed to twirl that DNA into chromosomes, insert it in a cell, and make a new eukaryotic life form?   Letting this kind of technology be available to the public is something that is currently forbidden, at least in current American society.   What kind of societal changes would required for people to believe that such technology is safe?

Still, it’s another possible technology for a hypothetical sustainable and starfaring civilization.  Perhaps in the future, we’ll have computers that are as much biotech as chips, where spam is something you feed your machine to support its self-repair function, rather than something you delete from your inbox.

Or maybe we should try to baked clay tablet thing…

 



And we thought hibernation was simple…
November 24, 2015, 7:52 pm
Filed under: colonizing space, Real Science Content | Tags: , ,

Unfortunately, the article is behind a paywall at the moment so you can only see the abstract, but PNAS just published a draft genome of the tardigrade Hypsibius dujardini.  Here’s the Yahoo news piece on the finding.

Basically, tardigrades are microscopic animals that are renowned for their ability to be frozen, boiled, desiccated, subjected to a vacuum on the outside of the space shuttle and so forth.  They’re the ultimate survivors among animals, and I’m pretty sure that every SF writer who thinks about putting astronauts in hibernation is thinking something along the lines of copying tardigrade’s toughness in humans through some futuristic technology.

But there’s an itty bitty catch.

If the draft genome is right (and there’s no reason to think it isn’t), tardigrades just took the record for having the most foreign DNA in their genome of any animal, about 16%, double the previous record holder.  They’ve got genes “derived from diverse bacteria as well as plants, fungi, and Archaea.”

My first thought was of Brin and Benford’s Heart of the Comet and the weirders (I still like that book), and then that ooh, massive horizontal gene transfer will take us to the stars!  Yay!  We get to go as gardens.

Then I read some more and found out that tardigrades’ toughness comes at a price: their DNA falls apart when they’re desiccated, and their cells get leaky as they rehydrate.  As a result, DNA from the surrounding environment gets taken up into their cells and, where it’s useful somehow, it gets taken into the tardigrade’s rebuilding genome.  Now bacteria do this all the time, so what’s unique here is that an animal has separately evolved the trick.  It’s one hell of a trick too, being able to repair eukaryotic DNA at that level and to usefully incorporate genes from wildly different organisms.  There’s a lot to be learned from these cute little water bears.

Still, this puts a whole different spin on putting people into hibernation to send them into deep space and to the stars.  It looks like tardigrades don’t have a magical way to avoid the damage caused by freezing.  Instead, it looks like they’re amazingly good at picking up the pieces afterwards and rebuilding themselves.  Presumably, that’s what we’ll have to learn to do (assuming it’s possible–tardigrades don’t have big brains),  if we want to turn people into corpsicles and back again without damage.  At the moment, the only methods we know of involve the use of either narrativium or handwavium, and both these elements are really unstable.