Swimming in Sand II: some facts, more fiction ('Tremors' & 'Primeval')

The previous post and the appendix dealt with Dune's sandworms, and how difficult it would be to getting millions of tons of sand out of the way to make such animals move. While the hard-boiled scientist in me rejected them as utterly impossible, the somewhat more romantic SF fan, also inside me, decided not to care one bit.

The size argument probably means that any real sandswimmers, by which I mean those on earth and in serious speculative biology projects, had better be small. Are there any other limitations on what they can do? Can sandswimmers dive as deep as they like?

I searched for an answer by looking at the physics of soils. Not surprisingly, the pressure in sand or another type of soil gets deeper the deeper you get, the same as pressure increases with depth in water. Typical soils contain not just grains of sand, but water as well. That complicates matters because there are separate pressures of the grains and the water between them. Luckily we can forget the water component as we are dealing with pure, dry sand. Comparing the effects of depth in water and sand reveals that sand isn't really a fluid.. They have in common that pressures increases with depth, and more so in sand, as it is heavier. But in water the extreme pressure at the bottom of an ocean trench does not stop fish from moving at all, whereas I imagine that movement is impossible under even two (maybe even one) meters of sand. While this seems intuitive, I found no readily available physical explanation. I suppose it has to do with the internal friction between grains of sand.

Click to enlarge. From: Baumgartner et al. Investigating the Locomotion of the Sandfish in Desert Sand Using NMR-Imaging. PLoS ONE 3(10): e3309. doi:10.1371/journal.pone.0003309

Loosely packed sand can be shaken, and then it sort of acts like a fluid. The image above is in fact from a study on sandswimming lizards, in which the authors speculated that decompacting sand might make it more fluid.

Click to enlarge. Copyright Gert van Dijk

But simply adding more sand on top would cause the sand to become impacted, and then no amount of shaking is going to create spare room. That is what is shown here. If something (a sandswimmer!) starts pushing a number of grains upwards, an entire column of sand above needs needs to be shifted. In fact, initially that column might look more like a cone, until the grains start shifting. At any rate this is real work.

What all this suggests is that pressure limits swimming in sand to superficial layers. A consequence of that would be that you would see the surface move when the swimmer is passing. It does not seem likely that sandswimmers can swim up to a potential victim without that victim being aware of the sand apparently moving of its own accord. Obviously, if the sandswimmer is a herbivore, any plants it is creeping up on wouldn't notice that. But sandswimming predators that wish to devour surface-walking prey had better do so from an ambush. Having said that, let's have a look at more fictional sandswimmers.

'Tremors' is a film about monsters ('graboids') that beleaguer a small community in a desert environment. The graboids swim under the sand at an amazing speed. As you can see from the video clip, they do break the soil above them, so the filmmakers gain some points for that. The speed at which they move is ludicrous, I am sorry to say. I couldn't see how the animals move: no bristles or legs or anything else I could find. The scene in which the graboid crashes into a concrete wall is wonderful from a story-telling point of view, but less so from a biomechanical point of view. It's not that the animal wouldn't get hurt, hitting concrete at that speed, but that the packed sand it moves through with ease would in reality provide a similarly unyielding obstacle. Anyone who ever took a failed dive and belly-flopped on water knows how hard water can be when struck at some speed. Now take the same dive on sand: there wouldn't even be a dent in it. The same principle is at work with sand sacks: they stop bullets. So I am sorry once again, but graboids are not feasible as shown. As was the case for Dune, I do not think that this harms the enjoyment of the film in any way. Apparently, the needs of fiction outweigh the needs of facts (Mr. Spock might have said that, but I did). Luckily 'Tremors' has a lot of humour in it, so I feel the same about it as I did with Dune.

The scene above is from a British television series called 'Primeval' in which time portals come into life now and again, allowing past and future wildlife to blunder through and run amok in England. In this scene a villain has captured some Silurian scorpions and uses them to terrorise a beach. The scorpions are a lot bigger than they were in reality and are supposed to be excellent sandswimmers, with lots of long limbs sticking sideways. Hmm; that can't really help their sandswimming abilities. When they approach, sometimes you see the sand move, particularly when the scene require drama to be built up, while at other times the scorpions strike without causing as much as a ripple on the sand.

There is a delectable irony in the Primeval scene. A man has been buried in the sand by his children. This is what people do at beaches, and if you search Google or YouTube, you will soon find examples of people being unable to free themselves, especially when the tide comes in: one wave of water can undo a minute or two of frantic digging by bystanders. In the Primeval scene, the buried man cannot free himself, and through this nicely illustrates that humans are very poor at sandswimming. And then the scorpion swims in, from deep beneath the ripples, and sucks the poor man under. Unfortunately, there is nothing about a man-sized scorpion that would make it a better sandswimmer than its victim. I guess the reasoning was once again that "The needs of fiction outweigh the needs of facts".

Swimming in Sand 1a: Dune appendix

Strictly speaking this post has no exobiology in it, so has no place here. But I could not resist digging up the only painting I ever did of an existing work of SF, and that was Dune, the subject of the previous post. So here it is. The painting is (shockingly) old, but the lettering is all new.

(Until now New Hades Publishers specialised in nature books -have a look at the Furaha site-, so this must be a new approach for them.)

Click to enlarge; copyright Gert van Dijk

Why no sandworms? As I said before, for me Dune was about people foremost, and sandworms second.

Swimming in Sand 1: the Sandworms of Dune

Sand is an odd material. In some ways it is like a fluid, as you can scoop up a handful of it and let it run through your fingers. Still, hills and dunes of sand will hold their shape, which water cannot do. You also cannot stand on it, and if you are buried underneath even a few decimetres of it on a beach, you will find it is much more resistant to movement than water is. Some animals 'swim' in it though, both real and fictional ones. There seems to be enough material for more than post, so this one is just the first. To start, let's begin with SF's biggest sand swimmer.

Click to enlarge; painting by John Schoenherr

Click to enlarge; painting by John Schoenherr

This is Shai-Hulud, the sandworm of Arrakis, the spice planet! These paintings are by John Schoenherr, a brilliant SF illustrator who died in 2010. Sandworms started life in Frank Herberts's Dune, an SF classic. I loved it when I first read it, several decades ago. I think I read the original novel more than once, but cannot say the same for the sequels, of which I may have read two, or perhaps even three (I tend to dislike trilogies with more than three volumes).

Much has been written about just about any aspect of the Dune books, and the sandworms are no exception. In fact, there is an entire book devoted to 'the Science of Dune', and one chapter was devoted to 'The Biology of the Sandworm'. You can download that chapter for 1 US $ here. I liked it, as it explored sandworm biology by comparing it with Earth biology. Sybille Hechtel, the author of the essay, had this to say about sandworm movement: "Herbert never describes precisely how the worm moves, only that it looks like a fish that 'swims' just under the surface. He frequently describes the worm’s motion in sand as 'a cresting of sand,' or mentions the 'burrow mound of a worm'. The worm primarily comes above the surface when it’s eating a ’thopter or crawler, or when the Fremen catch one and put their hooks in its scales to drive it up out of the sand." Well, that means there is no information whatsoever in Dune about how sandworms move. Starting with the word 'worm' there seem to be two major Earth modes of movement to compare it with.

Earthworm movement; click to enlarge; copyright Gert van Dijk

The first are earthworms. These move in an ingenious way, as the segments of their bodies can change shape: when they are short and wide, they press against the soil and anchor themselves to the soil. Any segments behind them that are long but narrow can be pulled up by shortening them in turn. The beauty of the system is that any segments in front can be pushed forwards by narrowing them. In this way, shortened segments function as anchors for thinner segments in front and behind. I have no idea whether or not sandworms are supposed to move like this, but one thing is certain: to move forward, earthworms have to force the soil aside to make room for their body.

Undulation; click to enlarge; copyright Gert van Dijk

The second way is by undulation, that way snakes, eels, and lots of Earth fishes move. the body moves in bends, and each bend pushes against the material around it. Those forces have sideways (blue) and backwards (red) components. The reaction forces of the material push the animal forward. Again, one thing is certain: whether in water or soil, the animal has to push that material aside to make room for its body in front of it.

So however sandworms move, they have to make room for their bodies. There are only two ways to do that: if the stuff around you is compressible, you can compress it, and otherwise you have to shift it. Water is almost not compressible at all, and sand doesn't compress well either. That leaves shifting it, and the only direction to shift it in is upwards, which sounds like a lot of work. Moving aside water is fairly easy; the fact that the largest animals on Earth, whales, live in water proves this. But the energy costs of shifting sand upwards are probably much higher, something that will probably recur in future posts.

Sandworm scale; click to enlarge

One thing is certain: more sand means more work. So how much sand must a sandworm shift? Well, the biggest sandworms are supposed to be 400 m long with a 80 m diameter. That is big. Very big. In fact, that is longer than a US aircraft carrier (only 333 m) and in the same league as the biggest super oil tankers (458 m). The Wikipedia page on tankers had a very nice scale drawing showing that tanker as well as some of the world's largest buildings, to which I added two sandworms: a puny 200m one and a fully grown 400 m one.

The clip above (taken from YouTube) is from the 1984 film adaptation, and nicely conveys the scale of the worm. Also look back at the paintings and look at the humans, giving a sense of scale. If such an animal is to move one body length forward, it will have to displace the volume of its body in sand. Assuming a completely cylindrical body, the volume of a 400 m sandworm comes out at a bit over 2 million cubic meters. I found figures for the mass of various forms of sand. The lowest density concerned loose sand, so let's use that. One cubic m of loose sand has a mass of 1442 kg, so the mass of the sandworm's volume in sand is 2884 million kg.

I hope these numbers convey the nerve Herbert had in thinking up such a monster. I must say that they impressed me. Regardless of whether a sandworm moves like an earthworm or undulates, displacing all that sand is serious work! Aircraft carriers run on nuclear reactors, and supertankers take ages to turn around. That is in water, a much more forgiving medium than sand. Simply pushing against sand with big muscles isn't going to do the trick. In this respect it is intriguing than no illustration of a sandworm I've ever seen shows anything in the way of a propulsion system. No limbs, no bristles, no segmental thinning, nothing. That goes for paintings well as the film and TV adaptations. Perhaps there are workarounds...

• One solution would be to give Arrakis, the sandworm's planet, a very low gravity: moving the sand would still require overcoming its inertia, but at least it would weigh a lot less. But reducing gravity has other effects: humans on Arrakis could jump around a lot, but the story doesn't mention that, so that's off.
• Perhaps the sand could be made lighter? The website I mentioned above states the density of lots of materials. Powdered carbon only masses 80 kg per cubic meter, and pulverised kaolin (china clay) weighs in at only 352 kg. Better, but still...
• Perhaps the friction between grains of sand can be reduced, but you wonder whether that is possible while still allowing people to walk around on sand.
• Are sandworms hollow cylinders? If so, then the sand inside their bodies could more or less stay in place. That would reduce the volume needed to shove aside. Perhaps their large size is a way to enlarge area without necessitating a large volume; who knows. It would not do wonders for friction though.

I am afraid that the only way out is to use a lot of 'handwavium', which basically means not worrying about the impossibility of sandworm movement. After all, suspension of disbelief is what keeps SF going. Does this make Dune a silly book? Not really, I think. I liked it very much when I first read it, and countless others did and still do. I only get irritated when authors or film makers pretend to be accurate and then blatantly are not. It is like the difference between someone who says he can bend spoons with psychic powers and someone who won't tell you how he does his tricks but acknowledges that they are tricks. Sandworm movement is such a trick...

It's a 'Fish'!

One of my good intentions for this year was to cut back on blogging. I did have my doubts whether this was really a good idea, as I like writing. Still, blogging keeps me from painting, and I had been postponing that for too long. I had decided to switch from brushes and artists' oils to digital painting about a year ago, but my first attempts proved a shock: I was used to applying paint where I saw the tip of the brush, and now there was a large distance between the graphics tablet and the screen. There were other mishaps as well. Even after changing Photoshop for Painter (more on that here) I still procrastinated, until I put aside enough time to really play with the brushes. Once I managed to forget what I was doing, my visual and motor skills, such as they are, met again and renewed their friendship. To make a long story short, here is my first digital painting I feel I can show the outside world. It's a fish. Sort of.

Click to enlarge; copyright Gert van Dijk

To be more precise, it is a Fusus rostrauctus of the Clade Fishes IV (Proculcapiti). I may have to check naming conventions here though. Anyway, I revealed a glimpse of Fish evolution previously, which I will not repeat. You may observe the typical traits of the Clade, but I will focus on artistic matters here (just as well, as there were some sudden changes in their anatomy compared to the rough sketch in the earlier post!). Having done a fairly large number of full paintings in oils for the eventual Book, I felt I needed additional illustrations, highlighting individual species, cladograms, things like that. This is the first of those. I wished to keep the painting style more or less the same as that of my previous oil paintings, and think I managed. After messing about with Painter's very large assortment of brushes, I settled on just two, and used those throughout (for those in the know, I used a detail oil brush and a blender, but tweaked size, opacity, 'resaturation' and 'bleed' continuously).

Just for fun I will show some layers of the final painting. The nice thing with digital painting is that you can use layers of colour that stay separate, so you can go back to a deep layer even after you painted others over it. In a 'real' painting ('physical' painting?) the only way to correct a deep layer is to scrape it, and everything on top of it, away altogether.

Click to enlarge; copyright Gert van Dijk

So here is the start of my project (it's not a tutorial: I'm not good enough for that). I started with a rough sketch and simply changed lines and shapes until the concept became more or less ready; that is the image on the left. I then drew a much neater line drawing on another layer, and used that as a guide for the painting job: the one on the right. In old times, I would have done exactly the same, but using various sheets of paper for the sketches on the left and one sheet of transparent paper for the one on the right.

Click to enlarge; copyright Gert van Dijk

After that you start painting. In this case I chose flat colours to start with. With oils, this basic colour layer would have obscured the line drawing on the board. Digitally, things are different: you can paint underneath your sketch, so that stays visible. Very odd at first, but extremely useful. The base colours are on the left, but without the line drawing. After that, another layer was added (on the right), and that is where it becomes interesting: that one modifies the base colours with shadows and highlights, as well as with some subtler colour changes here and there.

Click to enlarge; copyright Gert van Dijk

After that I decided to add another colour layer (I should have done that before, but, as I said, I am new at this). The rest comprises adding some reflections, details, some final shadows etc., and there we are. Mind you, the original is almost 7 times bigger, so some detail is lost. Anyway, here's my first digital painting. I hope you like it.

Birds with clubs and other smashers: clavigerism

I intended to write just one blog entry every two weeks this year, and am already breaking that rule. I could not resist, after reading a paper on an extinct Terran bird. The similarities to some Furahan creatures were simply too interesting to leave it alone, so there you are.

The bird, a flightless ibis, was described in a paper entitled 'The bizarre wing of the Jamaican flightless ibis Xenicibis xympithecus : a unique vertebrate adaptation' (Longrich NT, Olson SL; Proc R Soc B 2011, online 5 January 2011).

Click to enlarge; Longrich NT, Olson SL; Proc R Soc B 2011, online 5 January 2011

And here you see a reconstruction of the bird (top) and a comparison of its wing bones (bottom) with that of a still living ibis species. The authors make a case that the bird was flightless, and go on to say that the wing bones are odd for flightless birds. That holds for the hand in particular, with its thick and curved bone. The authors think it functioned as a club, and provide various anatomical reasons why they think so. After that, they discuss the club some more:

"We therefore propose that the wing of Xenicibis functioned as a club or flail. Several features of the limb would have facilitated this function. Kinetic energy is the product of mass and velocity squared; accordingly, weapons such as clubs and flails have a long handle to increase the angular velocity of the club, and are heavily weighted to increase the mass accelerated by the swing, and the centre of mass is near the end of the club, where the angular velocity is highest. Precisely this design is seen in the hand of Xenicibis, where the end of the wing is massive, and the proximal metacarpus and long forelimb could act as a handle. "

The authors of the paper also compare this odd ibis design with the front legs of mantis shrimps (Stomatopods), that function in a similar manner. The video above shows a slowed down version of a strike, and incidentally allows the shape of the club to be appreciated as well. It is taken from the lab of Sheila Patek, whose work on the biomechanics of their legs featured in this blog previously.

Click to enlarge; copyright Gert van Dijk

A long time ago mantis shrimps were the inspiration for Furahan neocarrnivores. You will find more material on them on the Furaha site (go to the land page). One of them is shown here (one of its commoner names is 'pugile'). Compare its front legs to those of mantis shrimps and to the ibis; I think that the ibis still had a long way to go before its clubs measured up to those of other club bearers. Then again, they were probably meant to hit other ibises, not kill prey animals, and it might not be advantageous in the long run to kill fellow ibises; merely sending them off might be good enough.

Stomatopods, Xenicibis and Furahan neocarnovores may all be said to have developed their clubs from what originally were locomotor limbs. In the Stomatopod and Neocarnivore cases, the limbs in question were used to walk with, and in the Xenicibis case its ancestors used them to fly with. In all cases their freedom from locomotion opened the door for a new function, and interestingly the new function was a weapon in all three cases. I think that Xenicibis therefore qualifies as much as the other two as an example of 'centaurism' (more on centaurism here and here).

I am delighted that we now have an example of 'raptorial centaurism' concerning a fairly large animal on Earth. Both Stomatopods and Furahan Neocarnivores have evolved various kinds of front legs, functioning as different types of weapons: there are 'smashers' and 'spearers' in both cases (Neocarnivores have webs or basket-like thingies as well). It would be great if more diligent paleontological work would uncover a 'spearer' on Earth as well, but I will not hold my breath. Meanwhile, perhaps it is time to coin a phrase to start differentiating between the various kinds of weapons limbs may turn into. 'Smashers' sounds good, but is limited to English, and that won't do. Luckily we still have Latin. A 'claviger' is an existing word for club carrier, with the plural 'clavigeri'. Turning it into a principle would result in 'clavigerism'. I don't expect a follow-up paper on Xenicibis to use the word; then again, the authors used the interesting phrase 'volant species' for birds that actually fly, so perhaps they can appreciate a bit of biogeekery...

Nereus (or how you can have radial flight with an odd number of wings)

As regular readers know, I am always on the lookout for creative projects concerning speculative biology. On places like Deviant Art you will find many interesting alien or alternate animals. Some feature new traits, others rework well-known themes; some are professionally drawn, others are less so. But what interests me most if there is a background: are there biotopes, is there a food web, do the predators match the prey, etc. That shortens the list considerably.

Some large projects have been in existence for very long times, and it does not feel entirely right to discuss them here. But there is one project, Nereus, that is relatively new. Its creator, Evan Black, does not mind, so that helps. Apparently Nereus received its name because humans first thought it was a water world (Nereus is a being from Greek mythology). The earliest post on the Nereus project on the Speculative Biology forum dates from May 2009. Evan has already produced 100 species and aims to achieve no less than 200 species. That is a lot or work: creatures have to be designed and described, and also drawn. I like the way Evan draws animals: while a bit stylised, they are very energetic, and as design they work: what you see are lively animals.

Click to enlarge (VERY much so!) Copyright Evan Black

Here is a start: a rather large cladogram of current Nereid species. Don't be surprised to find that the one on Evan's site differs from the one here, because he might have added a new species by the time you go there...

The Speculative Evolution pages contain discussions and comments on how Nereus develops, but I much prefer to see the result on Evan's own site. There, you can work your way through the menu, clicking on the Latin names of the various groups until you get to individual species, but you do not see what you are aiming for until you get to the species pages. Once there each species has two pages: one with text and a thumbnail, which leads to a much larger image with additional text. But there is another way to browse Nereus that I much prefer, and that is to choose 'world', and then 'cartography and climates'. That will take you to a list of 7 biomes, and clicking on them rewards you with an overview of that biome and small images of the species in it, that you can then pick and read at will.

Click to enlarge. Copyright Evan Black

As an example, here is the 'Sog Basin'. Sog "carpets the landscape like a thick tangle of spongy red veins", which sounds a bit like Well's Martian weeds. Luckily, there are no intelligent aliens around to regard Earth with envious eyes (or not yet). Sog sucks up water from the few available sources, and transports it across the otherwise dry biome. Leaks in the sog create watering holes, on which many species depend. Now that is why I prefer creations with a background: you immediately start to think how that works, how such species might look, etc.

Click to enlarge. Copyright Evan Black

Here is one such species: the kappa (Nothorana pratensis). It is a predator lying in wait in sog ponds, with just its dorsal eyes and its nostrils above the water. Take a good look: the kappa has three legs: two paired front ones and one unpaired jumping leg in the back. The illustration also contains a classification list containing the familiar Linnaean scheme, which starts at the species level and goes all the way up to the phylum Tetrabrachia (that would be 'four arms', if I remember my Greek correctly). One of the nicest things about Nereus creations is that it all fits together. Look up the Tetrabrachia, and you will find a page devoted to their anatomical Bauplan.

Click to enlarge. Copyright Evan Black

And here it is. The four arms in question concern four major nerve trunks emerging from the central brain. One trunks goes upwards, and that one deals mostly with sensory functions, which in modern Tetrabrachia has caused them to develop a head. The other three trunks control movement. In effect, what we are seeing here are radially organised animals, and I like the idea of taking radial animals rather further than they have managed to do on Earth (see the discussion on tetropters here, here, here and you can more on tetropters yourselves; here is something about radial symmetry; if that is not enough, just search for spidrids on this blog). But the kappa does not show radial symmetry; it is blatantly bilaterally symmetrical, and the legend includes information just when that happened.

Click to enlarge. Copyright Evan Black

I cannot resist showing one particular specimen, and that is because Evan and I discussed its s flight mode. Again, this is a radial life form. Most flying forms on Nereus are bilaterally symmetrical, resulting in flight plans that are superficially similar to the ones on earth. Not so the Cliff Whistler (Cadosmilos Aetopsis).

As you can see, it flies a bit like my tetropters. The tetropter discussions may have helped inspire the Cliff Whistler, which is flattering. Anyway, the Whistler flies by beating its three wings horizontally to and fro. Diehards out there may remember that I made extensive use of the 'clap-and-fling' principle to explain tetropter flight. The 'clap' involves two wings beating against one another at the end of their movement, then sweeping back to the other end of their range, where they then clap against another wing. Etcetera. That works with two wings (Terran insects and some birds), four wings (Furahan tetropters) and would work with more wings too, although no-one has yet invented any of those yet as far as I know. Besides offering increased lift through 'clap-and-fling', an even number of radial wings neatly solves the problem of torque: if a wing moves clockwise it pushes the body counter clockwise, which is useless. With two or four wings these forces even out.

Three-winged radial flyers run hnto problems. There is no clap-and-fling mechanism, and the wings move in unison: all three clockwise, and then all three counter clockwise. That leaves torque to be solved. Well, evolution, in the form of Evan, designed an adaptation of the Whistler's mouth parts at its bottom: these evolved into winglets beating in the opposite directions of the main wings, countering to a degree. Enough for the Cliff whistler to be a viable organism, or so Evan and I thought.

Recently I came up with a way to have a clap-and-fling mechanism with just three wings though. It would increase lift but introduce some new problems. Again, Evan and I thought that it might work, but not necessarily better than the Cliff Whistler approach. Perhaps one species will emerge on Nereus with this particular mechanism, we would have to ask Evan. I am not going to tell you how it works, merely that it can be done: each of the wings A, B and C claps against another wing on the extreme ends of its movement range. I wonder if anyone will take the bait...

The woolly-haired Shuffler: Splendid Insulation

It is cold outside. Then again: there will be a white Christmas, which is largely nice. All that snow led me to choose a wintery scene for my long overdue update of Furahan animals. The update follows the same pattern as previous ones: if I show a new animal, an old one leaves the scene, and that is exactly what has happened. After all, if the Furaha Project is ever to become a book, there should be things in it that are not freely available on the internet.

Click to enlarge; copyright Gert van Dijk

Here is part of the map of Furaha showing the usual covering of snow in Winter for the Northern hemisphere. This is part of the area where the woolly-haired Shuffler lives.

Click to enlarge; copyright Gert van Dijk

You will find the Shuffler on the land page, but here it is again. I could not resist adding some additional information here. At first glance you may wonder where the woolly hairs are, as the animal looks somewhat naked. Well, the hairs are underneath.

There are various ways in which animals can combat heat loss in a cold environment. Behavioural solutions are to stay indoors or sleep through the winter. There are anatomical tricks as well; a good principle is to be as round as possible with as few protruding parts as possible, in order to get a small surface area for a given volume. So, expect small ears, short tails and thick legs for animals in cold climes. A second anatomical trick is to be large, as it is easier for a large animal to conserve heat. There are metabolic and circulatory tricks as well, but a good theme is insulation. Layers and layers of fat wrapped around the more costly parts of the body will help, and as an aside these can store food as well. One of the best insulating materials is air. Fur works because the hairs trap air near the body, preventing the freezing effects of wind to reach warm parts of the body. Fur on Earth works quite well, and various animals have such sophisticated fur designs that they can withstand horrible conditions. Just consider hair that traps sunlight, leading the warming radiation into the body; hairs that are fairly thick but hollow, so they trap even more air; or consider fur made of layers of hairs with different characteristics. But such furs can still get wet, and while even that can be solved -think of polar bears- there is another way to protect against wind chill, and that is the ways humans do it.

Humans? Naked apes? I am talking about clothing. Animal pelts must have been among the first items of clothing, and among women of a certain class, a certain age and a certain cultural background fur coats are still in vogue (I cannot help but think -and sometimes say- that all fur coats are second-hand clothes, and that they invariably looked much better on the first owner). Fur coats work, but modern polar clothes are a miracle of ingenuity. They invariably have fibres to trap air much as hairs in furs do. But there is usually an outer layer of wind-breaking material to stop the trapped air from mingling with the really cold outside air. Animals don't have that, for the simple reason that it would not be easy to enclose large areas of air inside the body (oh well, Furahan tetrapterates do, but that is another story).

Once again, humans solved that particular riddle. Some brilliant Eskimo / Inuit must have realised one day that coats made of fur work even better when you wear the furry side of the pelt against your skin instead of on the outside. That was a stroke of genius, I think, but it is not listed among other great humans inventions such as fire, wheels and gossiping (the probable reason for the evolution of speech). I expect that women who like fur coats do not know this, and suspect they would ignore it anyway.

That Eskimo's idea is behind the fur coat of the Shuffler. Its skin forms folds, and the inside of the fold is covered in woolly hairs, while the outside is devoid of hair. The fold is dead, in fact. This might be as near as the 'Eskimo Invention' as biological evolution can get starting with hair on the outside of a body. The main downside is that investing in large amounts of skin and hair for just one season's worth of protection is costly in metabolic terms, so I played with alternative ideas, such as letting them keep their folds all year. Or perhaps they eat the skin when it falls off, in a rather unappetising manner.

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As you can see, I made some other changes to the web site as well:
I added a new book, on Warren Fahy's 'Fragment'. This is probably the only fake book in the entire New Hades catalogue of fake books that will one day likely be turned into a real book!. It is on the book page, of course.
The list of links has been reworked too, see the 'about' page. Snaiad is gone, but I will put the link back again when Nemo chooses to find a new host. Then again, Nereus is there now...
The illustration on the site's front page has been changed as well; no new items there, but I think it looks better now.

Finally, I have written too many posts on this blog: it keeps me from actually painting new Furahan life forms. Next year, I will probably reduce the frequency of posts to perhaps once every two weeks. We'll see. I do have some ideas for good subjects though. Meanwhile, please consider telling all women with fur coats, except for the ones you really like -the women, not the coats-, that they should wear their coats with the fur on the inside.