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Archive for April, 2011

How to Make a Zombie Plague

Ah, the zombie plague! A Mad Scientist couldn’t ask for a better means for world domination. Not only would discreet application of your infectious agent eliminate your opposition, the rest of humanity will be far too busy fending of their recently deceased loved ones to notice when you swoop in and take control. The population is reduced to a more manageable size, and the ever-present zombie threat will keep any potential rebellions from forming. Everybody wins! Well, mostly I win but you get my point.

But how to make it happen? There’s a good reason no one has ever pulled off the ‘Take Over the World by Zombie Plague’ scheme before…it’s an awful lot to ask of a single infectious agent. It must be transmitted from person to person, or even across species, quickly and with a low infectious dose. It has to fend off the immune system and penetrate the blood-brain barrier to get at your delicious brain meats. It has to basically turn your body into a walking incubation chamber, dedicated solely to feeding and spreading the infection. Still, these obstacles are not insurmountable when one has the power of Mad Science.

To put things into perspective, it is important to understand that the things that make us sick – viruses, bacteria, parasites, what-have-you – have been around a lot longer than we have, and they’ve gotten very good at what they do. And what they do isn’t very nice…we certainly don’t think so, anyway. The pathogens causing the infection are just doing what they have to do to survive and replicate in a hostile environment: You. In many cases, the characteristics that make this possible are a lucky coincidence for the pathogen and an unfortunate side-effect for the host. For example, a surface protein that makes a bacteria more resilient in the soil may also protect it from your immune system. If that bacteria spends enough time in a human host, it’s going to get better and better at exploiting that characteristic so that it can survive longer and reproduce more.

The longer this process goes on, the more specifically attuned the pathogen has the potential to become. Humans haven’t really been around very long, evolutionarily speaking. Bacteria however are some of the oldest forms of life, and the viruses that infect them, known as bacteriophages, have been fine-tuning the process for an exceptionally long time. So much so that many bacteriophages only infect one species of bacteria. They have become so specialized in exploiting the characteristics of their favorite bacteria that they have lost the ability to infect others.

Pox viruses are some of the oldest viruses that infect mammalian cells, and they have developed a similar level of species-specificity. A human could drink a vial of rabbit pox and be completely unaffected. That level of control would be useful…but that isn’t really what we want, is it? No, we want something new and flashy and explosively infectious. The Ebola virus only broke onto the ‘human infectious agent’ scene in 1976 and it has already made quite the impact. The virus itself destroys blood vessels and prevents blood from coagulating, producing lots of infectious fluids and causing death through hypovolemic shock. Bats are the most likely animal reservoir for the virus as well, which is pretty badass. Can you imagine zombie bats? I can. It’s awesome.

Unfortunately, viruses that are capable of infecting multiple species don’t generally affect them in the same way. The bats infected with Ebola aren’t leaking blood everywhere and birds infected with influenza haven’t come down with the flu. That’s because these species are carriers. While the virus is still present, it isn’t causing disease. Like the bacteria living in the soil that happen to have an adaptation that causes disease in humans, these viruses have a stable existence within their animal reservoirs. They only cause disease when they jump to humans, a less familiar environment. This is actually what makes Bird Flu so potentially dangerous. Multiple strains of influenza can infect the same animal, allowing for exceptionally rapid genetic recombination and the development of new strains our immune system has never seen. Many different animal species are reservoirs for human disease including pigs, armadillos and deer…but while they may be useful in delivering your zombie plague to the masses, your undead horde wont be accompanied by zombie armadillos. I’ll give you a moment to recover from the crushing disappointment.

So how will our zombie plague be spread? There’s a lot to consider here. Not only does the infection have to reach a lot of people, it also has to reach their delicious brains. The human brain is a fairly important organ. The blood-brain barrier carefully restricts access to the cerebrospinal fluid, protecting your tender brain from most bacterial infections as well as inflammation. Inflammation is your immune systems first response to a potential invader, but in the brain this can cause swelling and tissue damage. To prevent this, the blood-brain barrier keeps out the cells and antibodies of your immune system as well as the bacteria. There is certainly precedent for overcoming this obstacle, however. Rabies virus is spread through infected saliva and can travel from a bite wound to the brain, bypassing this barrier. Sound familiar?

But once our virus gets to the brain, how would it go about turning your average person into a shambling virus factory? Well honestly, you don’t really need most of that big brain you have. Sure, that cerebellum helps you coordinate your movements but shambling is totally in this year. As a proud soldier in the undead horde, you don’t really need to make any complex decisions so screw that  frontal lobe. And all that memory processing and spatial navigation provided by your hippocampus? Bah. All you really need is your amygdala…the primitive reptile brain, that generates the ‘fight or flight’ response. Just get rid of the rest and you’re good to go. Well, figuratively speaking.

So we’re looking for an infectious agent that can be introduced to the population in a relatively innocuous way – such as through an animal reservoir – that can penetrate the blood-brain barrier, destroy all that unnecessary brain tissue, and leave the host a shambling plague factory….preferably oozing with infectious particles. Now I’m sure most of you are thinking viruses are the way to go here, but I’ve got one word for you: Prions.

Prions are basically infectious proteins. We don’t know a lot about them yet, but they are the causative agent behind spongiform encephalopathies such as Mad Cow disease and Creutzfeldt–Jakob disease. Mad Cow disease can be transmitted to humans who eat infected tissue, and there is some evidence that prions can become airborne and cause disease at a surprisingly low infectious dose (in mice, anyway). Since all they are is a single protein, they have no trouble slipping past the blood-brain barrier and wreaking havoc with your neurons. When the misfolded prion protein encounters other proteins in the brain, it acts as a template that causes the misfolding of these healthy proteins, thereby propagating itself. Prion diseases are currently untreatable, even. The only real downside is the long incubation time, but I’m still pretty confident that prions are the way to go in terms of zombie plague development.

Even if you aren’t trying to take over the world (and why wouldn’t you be?!?), the zombie plague is exceptionally useful as a modeling tool for the spread of highly infectious diseases. It’s also a powerful motivator for getting people interested in how diseases spread. You can try your hand at destroying the world with the zombie plague or building your own custom pathogen to see how fast you can infect the world. Preparing for the Zombie Apocalypse is also a fun way to be prepared for more routine disasters that people do face daily.

Announcing the 2nd annual Science in My Fiction contest!

Science in My Fiction and Crossed Genres Publications are thrilled to announce our 2nd annual Science in My Fiction contest!

Last year’s contest was a huge success, and we’re excited to see what new and creative ideas authors can come up with this time!

This year the contest is slightly different. Here’s how it works:

Authors write a science fiction or fantasy short story inspired by a scientific discovery or innovation made or announced within the past year. It can’t be peripherally added: the science must be integral to the story. We’ll be looking for thoughtful, creative and well-researched application of science to a story. Writers must include a link to a relevant article or study of the applied science when they submit their stories.

Entries will be narrowed down to 10 finalists by the Crossed Genres publishers. Then a panel of judges will read and rank the finalists based on a points voting system. The top 3 stories will be published in Crossed Genres’ Science in My Fiction 2011: Offworld, an anthology of the 3 winning stories plus the 12 monthly stories published to the SiMF blog (Release date: 11/24/11).

Why is the anthology called Offworld? That’s the twist to this year’s contest. All story submissions must be set somewhere off Earth. It can be in orbit, on the moon, a distant world or in deep space, but the story has to take us away from the comfort of our home planet.

The winner will receive professional pay (5¢ per word) for their story, plus print and ebook copies of the anthology. Second place will receive 3¢ per word plus copies, and third place will receive 1¢ per word plus copies.

FULL DETAILS AND GUIDELINES FOR THE CONTEST HERE

2011 CONTEST JUDGES:

Tobias Buckell – Author (NYT Bestselling novel Halo: The Cole Protocol)
Liz Gorinsky – Hugo-nominated editor, Tor Books & Tor.com
Cameron McClure – Agent, Donald Maass Literary Agency
Joan Slonczewski – Campbell Award-winning author; Professor of Biology
Lavie Tidhar – Author (The Bookman, Camera Obscura)

Huge thanks to our amazing panel of judges for agreeing to help us out!

Submissions will be open from June 1 through August 31. So show us your science chops – prove to us there’s still a place for science in SFF!

FULL DETAILS AND GUIDELINES FOR THE CONTEST HERE

Fiction: “The Long Toss” by Gary Cuba

Hell of a way to lose, I thought, as I plowed my way through the detritus covering the parking lot.

I headed toward my office in Newton Hall, the center for Physics and Mathematics studies at Manley University. The trash was the day-old aftermath of the school’s final football game of the year. It consisted, in the main, of plastic beer cups, discarded game programs and empty half-pint bottles.

The students had been gifted with a good reason to get smashed. Once again, their team had managed to snatch defeat from the jaws of victory, ending their season with a record whose “wins” column consisted of an unblemished goose egg. What had made it all the more depressing was the way they had lost, on a last-second “Hail Mary” pass by the opposing offense. Heck, I thought. How had that scrawny Framingham Tech quarterback managed to throw the football so far, scrambling from deep in his own end zone? It must have traveled ninety yards in the air!

I plopped my heavy briefcase down on my desk and looked over at my office-mate, Harvey Atwood. Harvey was a full Professor, an aging don with dual doctorates in Physics and Chemistry. His unkempt, gray hair spilled across his shoulders, making his deep frown seem all that much more dour.

“Morning, Harvey. You look like you bet on the wrong team. How much did you manage to drop?”

Harvey snorted. “George, you know I try to stay clear of that sort of thing. Unless it’s a sure deal. No, there’s something else bugging me about that game–about that last play, that last pass.”

“Like, perhaps, the thought that it was impossible? That it violated the laws of physics and human physiology? Old friend, my lowly field of expertise may be in linguistic meta-geometry, but even I know that. It had to be a fix, a trick football. Filled with helium or something.”

“Not a credible hypothesis,” Harvey replied. “The volume-to-weight ratio is too small. You couldn’t pack enough helium in there to make a significant difference in the ball’s performance. But we saw it with our own eyes. It seemed impossible–but it’s obviously not. I’ve been tearing my hair out all night, trying to reason it out scientifically. And then, this morning I began to think about Dudley.”

Read the rest of this entry »

Gliese-Something-Something

If you know me, then you know that I am always on the lookout. For what? Science, of course, and art. Interesting and beautiful things. The internet is a better resource for novelty than anything else, but watchful and patient people sometimes get lucky. This was not an especially lucky week, but I did come across something that fulfilled my search criteria on technicalities. It’s pretty and it got me thinking – if my thoughts about it aren’t particularly favorable, they are at least energetic.

Don’t get me wrong, the video embedded below is essentially a modeling reel. It serves its purpose, which is to show-off some animation students’ acquired skills, and it’s quite good in that context. I have no desire to criticize their proficiency in the medium, but the obvious inspiration for the piece is a hot topic on this blog, so of course I took a closer look at it than I might have otherwise, and of course I brought it here to share.

Watch ‘Gliese 851′ then read on to see if it got you thinking along the same lines as me:

The first thing I noticed was the title. Now, there are a lot of stars named Gliese-something-something, but one has been in the news quite a bit more often than the rest; Gliese 581. Specifically because of that star’s unconfirmed ‘goldilocks’ planet. I assume the filmmaker was more interested in capitalizing on the name than on exploring any of the science associated with locating exoplanets or seriously speculating about extraterrestrial life. A couple of clues in plain sight verify my suspicion: For one thing, there is no star named Gliese 851, but that name is a common typo in articles about Gliese 581. For another, there appeared to be only two lifeforms on the wasteland planet depicted in the animation; one large human and one large tentacle-monster. Probably, the writer struck a compromise between savviness and laziness. The concept perfectly satisfies mainstream (i.e. low) expectations of science fiction, and it is about as deep as the average attention span for scientific content in the media.

But even assuming that the filmmakers invented a new star system on purpose, I have some questions about the setting. It looks like an industrial wasteland or a vast crash site. Or I suppose it could be an abandoned colony. Even still, why is the only human survivor wandering around in the open? With skin exposed? The atmosphere and daylight must be very earthlike, indeed. And if so, then what killed or repelled the other humans? Tentacle-monsters? But if so, then what did they eat/kill before humans arrived? I ask because I saw no evidence of other life on the planet, and it seems impossible that a species as complex as that alien could have evolved in the absence of biodiversity. Maybe it was the last of its kind. I mean, that’s possible given humanity’s propensity for environmental disaster.

What are your observations and speculations?

(W)hole Hearted

In preparation for this month’s post, I’ve been reading up on the heart. The post was inspired by my friend, Francesca Forrest’s, recommendation that I read The Sublime Engine: A Biography of the HUMAN HEART by Stephen Amidon and Thomas Amidon, MD. NPR had done a piece on the book discussing the man that toured Europe with a hole in his chest that allowed folks to see his heart hard at work deep within his chest. I was intrigued. Read the rest of this entry »

No Lorax Neccessary?

I am the Lorax. I speak for the trees. I speak for the trees, for the trees have no tongues. And I’m asking you sir, at the top of my lungs – that thing! That horrible thing that I see! What’s that thing you’ve made out of my truffula tree?

Find yourself a patch of forest. Sit among the trees and if you’re quiet (and a breeze is blowing) you’ll hear whispering and moaning. Folktales and legends say it’s the trees speaking to us. As Dr. Seuss’s Lorax points out, trees can’t really speak to us directly – at least not using words.

But even if they can’t speak, trees can indeed communicate. Back in 1982 Ian Baldwin, currently director of the Max Planck Institute for Chemical Ecology, published a paper showing that young trees that were damaged as if attacked by hungry insects increased production of tannins and several other chemical compounds. Those chemicals were known to inhibit growth and foraging of insect larvae and so presumably helped defend the trees from further attack.  They also discovered that undamaged trees in the same enclosure  started producing similar compounds. Baldwin and his colleagues concluded that the damaged trees were releasing volatile compounds into the air. Those chemicals served to warn the undamaged trees of potential danger, and induced them to begin to mount their own defenses.

Since then. advanced molecular analysis and genetics have been used to study the so-called “talking tree” phenomenon in more detail. Plant leaves release a number of different chemicals, from simple small molecules like ethylene to more complex compounds like methyl jasmonate. These compounds diffuse through the air, and if they come in contact with the leaves of responsive plants, those plants respond with changes in chemical synthesis and growth.

Plant roots also secrete a number of different communicating chemicals. These compounds aren’t able to travel as far through the soil as volatile compounds can drift through the air. Instead they locally fight of insect pests and battle nearby plants for growing room. Those chemical signals are also in the process of being deciphered, and that information is already being used to genetically engineer pest-fighting crops.

While the forms of chemical plant communication we currently are aware of are essentially  non-directed shouts of “Danger!” or “Stay away!” rather than conversations, a recent public Q&A session with Ian Baldwin touched on some more speculative possibilities.

So what about fiction?

SF has a number of examples of tree-like aliens (such as Orson Scott Card’s Pequeninos or the lonely female tree beings in Jack Skillingstead’s “Rescue Mission”) and fantasy creations like Tolkien’s Ents, but I couldn’t come up with any stories with scientifically plausible talking trees.

One big problem is intelligence – or more specifically the lack of it. To truly converse an entity must be able to think, and there is nothing that suggests that trees or other plants have any means of doing that. But once that hurdle is crossed (genetically engineered nervous systems, perhaps?), I think there’s a plausible leap to be made from the current simple modes of Earthly plant communication to full-fledged chemical conversation.

I wonder what they’d say?

More technical information:

Top image: Oak trees in October. Perhaps they are discussing the cooling weather? Photo by me.

Middle image: Methyl jasmonate. According to Baldwin, “Heavier compounds with less volatility, such as terpene alcohols, methyl jasmonate (MeJA), aromatic compounds including methyl salicylate (MeSA), and green-leaf volatiles (GLVs), are more likely to function as signals over longer distances, because their comparatively slower dispersal allows development of plumes of higher concentrations that may be carried farther as intact parcels by turbulent flow.”

Bottom image: “A Criminal Lead By Three Watchmen”, an illustration from Baron Ludvig Holberg’s 1741 novel Niels Klim’s Journey Under the Ground,  involving a visit to the Planet Nazar, which is inhabited by walking and talking trees

The Plastic Economy

Crude oil has been an easy source of energy for human use. It is very energy-dense (a lot of energy produced per unit consumed). So far it has taken much less energy to extract and refine the crude oil into gasoline, heating oil, and so on than we get out of it.

But that’s likely about to change, if it hasn’t already. We’ve used up the easy sources of oil; it’s harder and harder to extract oil, and uses more and more energy, so the return on investment is decreasing. It’s not so much that we’re going to run out of oil, it’s that it won’t be the incredibly cheap energy source that it has been. We’ve probably already reached the maximum rate of production (peak oil). US culture is built on cheap energy, everything from the mere existence of suburbia and shopping malls to the ease of air travel. What happens when that goes away?

That’s a really good science fictional question, one that Paolo Bacigalupi has explored in much of his fiction, including the Hugo-winning The Windup Girl, but it’s not the issue I’m interested in today. My question is what happens to all the other things we make from oil, and especially plastics. Our culture runs on cheap energy, but it’s packaged in plastic.

Crude oil is extracted, then refined into different fractions, things like gasoline, kerosene, wax, and heating oil. Some of these are burned as fuel, but petroleum products go into thousands of items, from pharmaceuticals to lubricants, cosmetics, even food (mostly the waxes), along with the ubiquitous plastics.

All of these uses, even plastic, can be duplicated using plant-based carbohydrates. That includes the energy uses: carbohydrates and hydrocarbons are interchangeable if you do enough work. The return on investment is just so much greater for petroleum than for plants, for plastics as well as energy.

As it becomes harder to extract petroleum, and as effective alternate energy sources become available, will burning petroleum still be the most useful thing to do with it? Burning petroleum releases carbon dioxide into the atmosphere from carbon that has been stored away for millions of years, demonstrably changing the ability of the atmosphere to retain heat and changing the global climate. No other use releases so much carbon.

Plastics are recyclable too. Using petroleum to make plastics can be a long-term investment. Discarded plastics are a major environmental problem in several different ways; increased crude oil costs may force better management of some of our more readily-disposable items. Plastic bags and drink bottles (especially water) may be among the worst offenders.

There are several possible scenarios. We could continue as usual, consuming the petroleum in the same ways as we do now, until we run out or the cost of extraction of the last drops is too great (do you really get all the ketchup out of the bottle?). At that point we no longer have cheap energy, or new plastics, or the myriad other things we’ve grown used to. Not fun in real life, but great science fictional material. Dump mining for plastics?

Or we can work to develop viable alternate energy sources, and save our petroleum for non-energy uses, and especially plastics. A greater focus on more efficient production, proper disposal and recycling could greatly reduce the environmental ill-effects of plastics, and we’d be able to keep making and using them for a very long time. Right now about 5% of US petroleum consumption goes into plastic manufacturing, both as feedstock and as energy source. Not as dramatically dystopian, but still interesting SF possibilities here.

At the other end of the scale, we can look at atmospheric carbon dioxide, the BP oil spill in the Gulf of Mexico, and all the human and environmental health impacts of petroleum extraction and transport and ditch it all as a bad job. There are alternative sources for energy, plastics, pretty much everything. If we made a commitment to researching them, we probably could drop oil completely. There’d have to be some lifestyle changes, I imagine. I’ve already got some story ideas…

I mentioned my April topic to a friend, and he pointed out an SF example from 1979: the novelization of Alien by Alan Dean Foster. (I don’t know whether the set-up was in the movie or not.) Foster writes:

That oil would be finished petrochemicals by the time the Nostromo arrived in orbit around Earth. Such methods were necessary. While mankind had long since developed marvelous, efficient substitutes for powering their civilization, they had done so only after greedy individuals had sucked the last drop of petroleum products from a drained Earth.

Fusion and solar power ran all of man’s machines. But they couldn’t substitute for petrochemicals. A fusion engine could not produce plastics, for example. The modern worlds could exist without power sooner than they could without plastic.

So what do you think? Where are we as a society going to head? Which scenario makes more interesting fiction? Which would you rather live in? Was Mr. McGuire right?

The Science of Red Mars

Mars. There’s something about the Red Planet that gets people excited. Sure, part of it may be that it is the most Earth-like planet in the solar system (except for Earth…) but even more powerful are the stories that are told about it. Mars has been the subject of myths since before recorded history, and more recently has been the setting or inspiration for reams of science fiction.

For those of us who like a little science in our fiction, the good news is that in the last decade our understanding of the Red Planet has grown by leaps and bounds thanks to a whole armada of space probes: Mars Global Surveyor, Mars Odyssey, Mars Pathfinder, Mars Express, the two Mars Exploration Rovers, Phoenix, and Mars Reconnaissance Orbiter.

All of these missions came after the publication of the classic hard sci-fi masterpiece “Red Mars” by Kim Stanley Robinson, so I thought it would be interesting to take a look at how Red Mars holds up.

The short answer is: pretty well! Kim Stanley Robinson did a phenomenal amount of research for the book, and the Mars that he describes is still remarkably accurate. The book is a tome, so I can’t go through and critique every bit of Mars science in it, so I will focus on a few key sections.

First, let’s look at the beginning of Part Three: The Crucible. (If you’d like to follow along, a PDF version of the book is available here, legally, for free) This section begins with a description of how Mars formed, and how it acquired its geography (areography?). The language takes some poetic license, but is generally accurate: Mars did indeed form along with the rest of the solar system about 4.5 billion years ago (I’ll forgive Robinson for rounding up to 5) from the gradual accretion of planetesimals, and it did have a short-lived magnetic field.

What Robinson didn’t know was that the evidence of that magnetic field is still preserved in the ancient rocks of the southern hemisphere! The magnetization was obliterated by the giant impacts Hellas and Argyre, but elsewhere in the southern highlands there are broad bands of opposing magnetic fields. These are similar to the alternating bands of magnetization preserved near tectonic spreading centers on the earth caused by the switching of the Earth’s magnetic field, but on a much larger scale. Some scientists have used this similarity to argue in favor of plate tectonics on early Mars, but there’s not a lot of other evidence for plate tectonics so this hypothesis isn’t very popular these days.

Robinson is also correct that the huge Tharsis bulge and its towering volcanoes probably are caused by convection in the mantle, and that a leading theory for the formation of the northern lowlands is that they are a single gigantic impact basin. This giant impact theory has been making a comeback lately. By using careful measurements of the martian gravity, scientists have been able to figure out how thick the crust is, and effectively “subtract” the Tharsis bulge. What’s left in the northern hemisphere is a gargantuan elliptical crater, 10,000 km by 8,500 km.

Oh how Robinson must wish he had this topographic map of Mars when writing! Blue is low, red and white are high. Tharsis is the huge high elevation area dotted with volcanoes west of the giant canyons of Valles Marineris.

The idea of Mars’ moons Phobos and Deimos as ejecta  from a similar giant impact is still alive and kicking. Mars Express has found evidence of clay minerals on Phobos, which only form when water is available. This, combined with the moon’s low density suggest that it is probably a piece of the ancient martian crust rather than a captured asteroid.

The intro to Part Three is also pretty accurate in its description of water on Mars. We now know for sure that there is water on Mars, and that there is likely a lot of ice beneath the surface. It’s not necessarily all in the form of pure-ice lenses like Robinson describes, but it’s there, and there seem to be lenses at least in some places, like the Phoenix landing site.

Finally, he’s spot on in his description of life on Mars (or the lack thereof) at the end of the intro to Part Three. Even the references to sulfur and clays and hot springs are accurate! Mars Express and Mars Reconnaissance Orbiter have both found evidence of clays and sulfates in the ancient rocks all over mars, and the Spirit rover has dug up sulfate- and silica- rich soil interpreted as the result of hydrothermal activity. But so far, no evidence for life. All the claims of life in Martian meteorites have been met with plausible inorganic explanations, and Phoenix has discovered perchlorates in the martian soil – powerful oxidizers that help explain the confusing results of the Viking landers’ life detection experiments.

Let’s fast forward a bit to page 131 of the pdf. Some of the colonists are on a road trip to the north polar cap to set up some automated ice-mining. Setting aside the implausibility of being able to drive halfway across the planet without any trouble, there is a statement made in passing here that really does reflect a fundamental change in our understanding of Mars.

“The rocks you see here come from late meteor action. The total accumulation of loose rock from meteor strikes is much greater than what we can see, that’s what gardened regolith is. And the regolith is a kilometer deep.”

This is an idea that was carried over to Mars by scientists who cut their teeth studying the moon. It’s certainly true for much of the moon, where there are few geologic processes other than volcanism and impacts. But one of the most significant things that has been learned about Mars since Red Mars was written is that it is not just a big red version of the moon. With the first really high resolution images of Mars returned by the Mars Orbital Camera on Mars Global Surveyor, and the spectacular even-higher-resolution images that continue to stream down from HiRISE on MRO, we can start to see Mars as it really is. Yes, there are lots of craters, and the regolith is made of ejecta from eons of impacts, but it’s not ejecta all the way down like it is on the moon. Mars has sedimentary rocks, and lots of them. Volcanic ash lofted thousands of kilometers by the martian atmosphere and deposited in blanketing layers, sand seas cemented in place by hydrated minerals, sediment settling through the icy waters of short-lived lakes. All of these combine to form thick sequences of layered rocks. Sure, there are also craters interbedded with the other layers, but cratering is just one of many processes at work on Mars.

An illustration of the idea of the martian crust as a "cratered volume" rather than just a bunch of megabreccia. Here, craters are interbedded with various layered rocks, going down many kilometers. (image from Malin and Edgett, 2001)

Even more amazing is how much the landscape has changed. There is evidence that huge swaths of the planet were once buried and have been exhumed by billions of years of erosion. In Gale Crater, one of the potential landing sites for the next Mars rover, there is a 6km high mountain of sedimentary rock that is taller than the rim of the crater it sits in. How far did those rocks once extend? In some places, erosion has partially uncovered craters that look for all the world like they should be freshly formed. Except that they are half buried under a billion years of rock.

It is difficult, even for those of us who study Mars, to look at the surface as it is now and remember that we are just seeing the upper layer of an intricate intermingling of processes, and that kilometers of rock may have been stripped away from above the present surface. It’s amazing what four billion years of erosion can do to a planet. Even though Robinson isn’t quite right when he writes that the regolith goes down a kilometer, he was right about the most fundamental difference between Earth and Mars:

“It’s billions of years. That’s the difference between here and Earth, the age of the land goes from millions of years to billions. It’s such a big difference it’s hard to imagine.”

Later in the same section of the book, Robinson reveals another case where the information available when he was writing pales compared to what we have now:

“Ann was crouching, a scoop of sand in her palm.

“What’s it made of?” Nadia asked.

“Dark solid mineral particles.”

Nadia snorted. “I could have told you that.”

“Not before we got here you couldn’t. It might have been fines aggregated with salts. But it’s bits of rock instead.”

“Why so dark?”

“Volcanic. On Earth sand is mostly quartz, you see, because there’s a lot of granite there. But Mars doesn’t have much granite. These grains are probably volcanic silicates. Obsidian, flint, some garnet. Beautiful, isn’t it?”

I thought this was quite telling because these days we have a very good idea of what the sand on Mars is made of, thanks to the spectrometers on Mars Express and MRO, and the results of the MER rovers. The nice thing about sand dunes is that they are self-cleaning: the saltation of the sand grains knocks the dust off of them, so the dunes on Mars often have nice clean spectra revealing a basaltic composition, with lots of minerals containing iron and magnesium. Robinson shows his earthly biases when he lists things like obsidian, flint and garnet – these all have much higher silica and aluminum than basalts, a good sign that the rock containing them has been recycled by plate tectonics. On Mars, just about everything is basaltic, or the result of weathering basalt. The same spectrometers that found the composition of sand on Mars have also found hundreds of examples of minerals formed by the interaction of water with basaltic rocks, but there are not many places where more processed, high-Si and high-Al rocks are found.

Jumping forward again to page 241 of the pdf, there are some interesting comments about glaciers and oceans on Mars:

“The glacial theory, however, and the oceanic model of which it was part, had always been more persistent than most. First, because almost every model of the planet’s formation indicated that there should have been a lot of water outgassing, and it had to have gone somewhere. And second, John thought, because there were a lot of people who would be comforted if the oceanic model were true; they would feel less uneasy about the morality of terraforming.”

We aren’t too concerned about the morality of terraforming yet, but the rest of this excerpt is pretty spot-on. The ocean hypothesis for Mars still lives on, partially because of new discoveries, but partially because people want it to be true. One interesting recent result took a look at all the features on Mars that might be deltas formed by rivers dumping their sediment into a standing body of water. Many of these are in craters, so you only need to invoke enough water to fill the crater, but there are some that empty into the northern lowlands, and they are all at about the same elevation. Likewise, the density of drainage channels on Mars has been mapped and it shows a similar cutoff with elevation. Are these results evidence of a northern ocean? Maybe, maybe not.

A map of the density of drainage channels on Mars, in relation to a hypothetical northern ocean. Image credit: Wei Luo/Northern Illinois University/PA Wire

As for glaciers, this is another area that has made a lot of progress since Red mars was published. Mars Express and MRO both carry ground-penetrating radar instruments designed to look for ice on the surface of Mars. These have given some spectacular cross-section views of the polar caps, but maybe even more important is the discovery that there are huge lobate masses of ice – some might call them glaciers – buried under thin layers of rocky debris on Mars. I’m a little surprised that Robinson did not mention these because they had been seen even before MOC and HiRISE sent back high-resolution photos. The radar results just confirmed that these lobate features were mostly ice rather than mostly rock.

A map of glacial ice (blue) discovered in the mid-latitudes of mars by ground-penetrating radar. The lobes of ice are buried under a thin layer of soil which protects it from sublimating away.

Overall, the science in Red Mars is remarkably good even today. If you want to get a good basic understanding of Mars science (or if you want to read an epic story of colonization, human drama, etc.) Red Mars is a great place to start. Still, we know a lot more about some things than we did when the book was written. We know that Mars has honest-to-goodness sedimentary rocks and a stratigraphic record that is more complex than just craters and volcanoes. We know a phenomenal amount about the composition of the surface thanks to orbiting spectrometers and the Pathfinder, MER and Phoenix landers. And we know that there is ice, not just at the poles, not just beneath the surface in the arctic, but in vast buried glaciers even in the low latitudes.

With all that we do know, it’s striking to me how many of the big questions about Mars that Robinson mentions in the book are still open to debate today. Did Mars have an ocean? Maybe. Was it ever warm and wet? Maybe. Is the northern hemisphere a giant crater? Maybe.

Is there life on Mars? Maybe. Maybe not. Maybe not yet.

Dreaming Robot Can’t Wake Up

ZaZa can't wake from dreams of being splashed.

Do androids dream of electric sheep? Apparently not, according to researchers at the Interdisciplinary Technology Institute in Boston. “Most of ZaZa’s dreams are about getting splashed.” Whether that’s the result of oversight or foresight, ZaZa’s vulnerability to liquids has been a boon to the scientists at ITI from the beginning of this uncanny project.

As part of their research into the relationship between dreaming and memory formation, ZaZa was created to be a learning robot. Scientists expose her to new stimuli and information every day and then assess her recollection over time. According to one researcher, ZaZa came in contact with an uncovered cup of coffee during the first week of the study, and immediately afterward, her dreams became less like randomized input logs and more recognizably dream-like. “After the incident, we instructed her to avoid all moisture in the future. We expected to see the event reflected in her dreams but we’re still surprised by the extent of its impact.”

Because organic brains are still far more complex than even the most advanced computers, scientists at ITI had to overcome major hurdles while designing the project. In order to construct a useful model of a human mind, they had to give ZaZa several ‘brains.’ In addition to the central unit in her chest, she has a computer to regulate and monitor each of her six sensor-types, another to coordinate the senses and simulate short term memory and recall, and a ninth computer dedicated to communication and dreaming. One would expect a robot brain composed of so many computers to be cumbersome and awkward, but ZaZa is surprisingly small; about the size of a kindergartner. Because ITI’s dream research requires that ZaZa be able to move around and interact with scientists, they took advantage of existing, inexpensive broadband mobile technology rather than reinventing the wheel for the project. As a result, little ZaZa is completely wireless and has a remote brain.

Wifi is only one of the technological advances that researchers at ITI have incorporated into the design of their dream-bot.  To give ZaZa the ability to learn like a human, they applied developments in self-organizing computer networks, simulated cognition and artificial intelligence, and even language acquisition and physical creativity. “The ZaZa Project is really a collaborative effort between ITI and dozens of other institutions. The individual advances made in their labs are brought together in ours.”

Considerable effort went into ZaZa’s outward design, as well. In order to inspire more ‘life-like’ dreams, they’ve equipped her with the social skills necessary to recognize human emotions and respond appropriately. For day-to-day interactions between ZaZa and researchers to be as normal as possible, they’ve even given her human mannerisms and appearance. One scientist said, “When all her systems are functioning optimally, you could almost forget she isn’t someone’s little girl.”

Of course, any system as complex as ZaZa’s is bound to malfunction at times. Because most of her brains are located outside her body, she slips into standby mode whenever the local wifi signal drops and must be woken manually. If even one of her computers crashes, scientists must shut her down completely and repeat the day’s research from the beginning. Simple physical problems, like replacing worn sensors, can be dealt with more easily because ZaZa doesn’t technically feel pain. However, every time she gets wet – a month after the coffee incident, poor ventilation in another lab at ITI triggered the fire sprinklers – ZaZa’s body suffers catastrophic failure and must be rebuilt.

When everything goes according to plan, ZaZa is still only awake for eight hours a day, five days a week. “ZaZa can’t be left unattended while she’s awake, so she has to dream while we’re all home on nights and weekends,” explained the project’s lead scientist. That’s perfect for their research because it means that during periods without major malfunctions, they still acquire enough dream logs to make up for the time they spend rebuilding and repairing her systems.

Scientists are naturally reluctant to offer much speculation about the results of this study so early in the project, but many researchers are already planning future studies involving ZaZa and conceiving new robots based upon her design. One such project has already been green-lighted by ITI, but the only details scientists would divulge about it were that the next generation of ‘dream-bot’ will be adult-sized to accommodate internal, self-contained computer brains. Also, unlike ZaZa, who spends most hours lying under a tarp unable to wake from dreams about getting splashed, their next prototype will be able to swim if necessary, and may rest, but never sleep.