Sunday, 27 December 2009
But there are quite a few creative people who design life forms for fun without all the rest of it. While a scientific background adds intellectual spice, not having one does not detract from the more primary, emotional type of fun of looking at a well-drawn animal. One example of this type of fun is the 'Diary of Inhuman Species' by Stan, who draws one species a day, as I wrote here earlier. Stan is still going strong, so do not forget to visit his site from time to time.
I came across another site with a constant stream of new odd animals, and like Stan's these animals should not be taken overly seriously. This is the 'Creature Journal' with the explanatory subtitle 'It's a journal with creatures in it'. It is written by 'Fungi' or 'misterfungi', also known as Mark A. Facey.
Here is one of his creatures to start with: the 'mensblodder'. You can see it shouldn't be taken too seriously, can you? I asked Mark about any systematic biological background; there doesn't seem to be an intricately worked-out one, but he was curious to hear what I made of it. I'm ready to make a remark here and there, but do not want to spoil the fun by being too intellectual about it. At first I thought this might be an animal with radial symmetry, based on the legs. Then again, the upper torso and head are clearly bilaterally symmetric, so that probably holds for the entire animal. It seems to have an internal skeleton, so it certainly is no Earth insect. Not that anyone would have thought that anyway. Seeing it's legs bent this way and that, it is either not very large or must live on a low-gravity world. Mark, is that anywhere close to what you had in mind?
It's a bird! It's a 'Cluckadon Tuft Puncher'. If you have seen films of birds of paradise, with their bizarre mating rituals and plumage, you can not think that this animal is wholly unearthly. Its posture reminded me of such birds, but I might be wrong: perhaps this is its normal standing posture. Then again, its name suggests a more pugilistic attitude: a threat posture? I would guess it is flightless, judging from the shape of its wings and its tail.
Click to enlarge ; copyright Mark A. Facey
The 'emerald nitpicker' is a tetrapod animal with an exoskeleton (look at the first joints of the hind legs); and why not? There is no rule stating that any animal with more than four legs in its body plan must be an arthropod and therefore have an exoskeleton. If larger animals can get away with walking on four legs, why shouldn't small ones be able to do the same? I can't help but wonder why its legs are in the position they're in. Are the front legs designed to catch prey? Is it a jumping predator? Regardless, it is very eye-catching.
The 'knuckleheaded guppy goblin', or, as I would label it, a fish. This certainly is a predator. I like the way its salmon-like head bump adds a sense of power to the animal. It's also nicely fleshy. It's not found in local waters, I think, as there anatomical clues why this is no mere Earth fish.
I hope you like Mark's animals as much as I do: they are fun and make me want to sit down and start painting immediately. In my case that usually involves oil paints, as I still have to make the -for me- difficult transfer to digital art. If any readers are in a similar stage, or wish to take up painting with Photoshop, Mark has posted a few videos showing how he paints a 'hulking shipwreck creeper'.
This is probably this year's last post. Then again, I might decide to post some more attempts at videos showing Furahan landscapes. Have a nice 2010!
Friday, 18 December 2009
Looking at the program makes you realise how fast computer graphics have evolved. Admittedly, the designers at the BBC probably did not have an enormous budget available, so they may not have been able to achieve the very best results technology could offer in 1997. In that period, 'Jurassic Park' was probably the yardstick you could get if you threw lots of money at the problem, and 'Jurassic park' dates from 1993. Still, the computer effects were certainly better than what an amateur could achieve.
I do not think that this means the program is no longer interesting to watch, so I decided to show some more fragments of the program. The one for today concerns life on high gravity planets. You will see an interview with Jack Cohen, a biologist with a strong interest in biology in science fiction. He has written a few books that all people who wish to design worlds should find interesting. One I particularly recommend is 'Figments of reality'; a search on Amazon should result in several others.
In the video, Jack Cohen goes into the mechanics of legs for heavy worlds. He compares land-living crabs with sea-dwelling crabs to make the point that higher loads require stronger and more columnar legs, an effect encountered in this blog more than once. The resulting animation is quite nice. Another point that should be kept in mind is that high gravity is largely irrelevant under water. If your body mass is close to that of water, it will not take much effort to keep floating at the same height, and a relatively small swim bladder should allow you to change height at will. There's no risk of broken limbs from tripping under water.
On land, of course, things are quite different. In a truly high gravity the simplest trip could shatter your legs, so falling is something to be avoided at all cost. Even staying upright and walking requires legs that look different from those of animals of similar size on a low gravity planet (that's why I thought that Alex Ries' Birrin must live on a low-gravity world).
The video fragment shows a vaguely arthropod-looking animal, shown above, with a large number of vertically placed columnar legs. This makes excellent sense. The animal has large wings though, and that may seem surprising. Wouldn't high gravity make it more difficult to become airborne? It would, as a moment's thought reveals: staying aloft requires that weight, dragging an animal down, is exactly countered by the amount of lift pushing the animal upwards. If you double gravity and keep everything else the same, the situation is no longer in equilibrium, as weight is now twice as large as lift. Down you go.
But Jack Cohen makes the point in the video that high gravity may also make it easier to fly, by increasing the density of the air. It is indeed more easy to achieve lift in a soupy atmosphere than in a rarefied one, and vice versa. Disney's people knew that in 1957, as evidenced by the enormous wings of his Martian flying animals, designed to fly in the rare Martian atmosphere.
I checked some books and found that the amount of lift provided by wings is directly proportional to the density of the air. Here is the formula:
lift = 0.5 x density x wing area x velocity squared x lift coefficient
What that boils down to is that doubling the density of the air will double the amount of lift. That is nice: in the example above gravity was supposed to be twice as much as on Earth, so a doubling of lift is just what we need to keep the same animal in the air. Not that is at all likely that an animal living on a planet with twice the gravity and twice the air density could be the same as one living on a lighter world, but never mind that now.
So, to make things work, the only remaining question is whether doubling the gravity a terrestrial planet is compatible with doubling its air density. I have no idea. Comparing Venus and Earth suggests that similarly sized terrestrial planets can vary widely as far as their atmospheric density is concerned, so I guess a double air density is feasible. If anyone knows more about the relationships between gravity and likely atmospheric density of Earth-like planets, feel free to comment on this post.
Sunday, 13 December 2009
The thing to remember about Eponan terrestrial life forms is that they left the sea fairly recently, so adaptations to a land-based existence have not yet reached optimal solutions yet. That holds for Eponan trees, whose stems have not yet evolved anything as suitable as wood, and it may also hold for the springcroc. Its general design is very nice: in essence a springcroc is just a large stomach enclosed by two half shells. It lies in waiting in some swamp, and when a suitable prey arrives in striking distance the springcroc catapults itself towards the prey using its own froglike leg. The prey is engulfed by the stomach and is slowly digested. Simple, but simple solutions work.
This is the springcroc as shown on the Epona site. Steven Hanly, one of the people involved in the Epona project, produced many 3D Epona images at the time, many of which can be seen on his web page. For this purpose he had also built a 3D springcroc computer model. A few months ago he sent me his 'obj' file to have a look at. I was also trying out ZBrush, a 3D 'sculpting' program that is extremely well-suited to produce organic looking animal shapes. I imported the springcroc shape, and used it to try out some embellishments, as ZBrush allows you to push and pull at objects at will. As you will see this ability is the reason why the poor animal now has so many bumps on its head.
I also decided to 'bodybuild' its musculature somewhat. With just one leg it must be difficult for the springcroc to control the direction of its jump in a lateral direction. While a jump in the general direction of the prey can work for extremely slow prey animals, a jump with some more precision should help the springcroc to rise to the pinnacle of the food chain (or at least to stay in plaavce with more ease). The only way the springcroc can exert lateral control is by pushing harder or less hard on either of its two toes while jumping, so these are fairly wide apart. For similar reasons the joints between the segments of its leg were broadened: to provide more joint stability as well as a bit more control.
Having done that, I exported the model again, and after some trouble loaded it into Vue Infinite, where I embedded it in a meadow-like environment of Eponan plant (well, actually one plant was designed for Furaha, but these images are sketches, nothing more). The springcroc should really be coloured a bit more interestingly, but this is just a work in progress. The white leaves reminded me of springtime, so there you have it: a springcroc in springtime...
Sunday, 6 December 2009
In the 1950s the Disney studios produced a weekly television series called Disneyland. One episode was called 'Mars and Beyond', which aired in 1957. It contains experts with heavy accents explaining things such as geosynchronous orbits to very attentive serious looking young men, but it also contains a short gem showing possible Martian life forms.
If you look at that part of the episode, reproduced below, you cannot help thinking that Disney's animators must have had a great time producing these scenes. Perhaps you have to overlook some of its now outdated aspects, such as the deeply sonorous voice. After all, this footage is over 50 years old. But if you look past that there is so much creativity that it is simply contagious. Some of the life forms in there look very far-fetched, such as the crystal ones that grow overnight and are shattered each morning. The daily cycle is a very nice and dramatic notion, but crystal life forms do not seem to have outlived the fifties and sixties in science fiction. I have always wondered in which ways a crystal would be said to be alive. Thought and even intelligence are not impossible; after all, neither neurons nor computer processors appear to do anything if you just look at them. It is simpler things such as movement that cause doubt, as well as procreation and selection. But never mind that; crystal life forms seem to belong a past concurrent with Star Trek's original series (which started in 1966, just 9 years after Mars and Beyond).
The plant that eats itself also seems impossible, because of problems with energy efficiency. Some readers might point out that one's own parts might be put to better use when the need arises, such as under extreme duress. Possibly, but there might be easier ways of recycling body parts than actually digesting such parts.
I really like the scene shown above, in the beginning, in which the camera pans over a landscape, and we see rocks over which luminous threads glide along in parallel. I do not know what these are or what they are doing, but I like the air of otherworldliness of the scene. Later on, there are shelled creatures that can 'clamp up' to protect themselves from sand storms, and those seem quite likely. The animals that sieve the top layer of the soil for something are a nice concept. You could imagine a thin layer of bacteria or unicellular plants living in a few millimetres of otherwise barren ground, and this biome would definitely require specialised animals to get at this source of food.
My favourite, I think, is a small ballont that hangs from, well, from something. When it lets go it first inflates and then seems to fly by jet propulsion, until it is -how sad!- speared by a sessile predator. Jet propulsion with stored air, now that is a nice thought! Disney's animal looks like a simple toy balloon that is let go, but there must be ways of making it more interesting. How about storing the air under high pressure, so the amount of air will last longer? That would take a fortified bladder, the walls of which must be capable of withstanding high tensile strength. Possible. The thing is how to pump the air in. Perhaps a series of muscular 'hearts' would do, each of which would increase the pressure to compress air into chambers separated by valves? Such an animal would run out of compressed air in flight, so this mechanism might work better as an additional power source than as the sole one. Food for thought...
Sunday, 29 November 2009
Saturday, 21 November 2009
One of the things that I am a bit disappointed about is Vue's plant editor. There is one, but it is fairly limited: it will let you alter existing designs, but you cannot design completely new shapes with it, and if you want alien forms, you need more freedom that Vue gives you. Of course, there is XFrog: it will allow you to do that, but it is difficult to learn and for several years now all development efforts have been directed at versions to be used with major 3D packages, leaving general users like me with the 3.5 version, that is by now rather old. Still, you can design very interesting shapes with it.
Animation is another subject that Vue must be able to do, as there are breathtaking demonstration videos available, but unfortunately most general users find it extremely difficult to get good results. In experimenting with animation I was not too disappointed, but my standards for animation might not be that high. It is possible that the latest version of Vue is better, but I am at least one version behind.
So here are two scenes from a very quiet swamp. The reasons it is so quiet is twofold: I should add some sounds, but I have never create an alien nature sound track yet. I do have ideas on how to do it, but it does not have a high priority. The other thing you will notice is that the plants and the water do not move at all. Vue can actually produce plants that move in a breeze, but that works only with its own type of plants, not with imported objects.
You can find the same swamp in the plants section by the way.
You may well find that the scene isn't that alien, and you would be right. I am guessing that branching plant shapes would converge in design across the universe, but I could have thrown in a few mixomorphs or ballooning plants to spice up the scene. Then again, there are items you cannot see that well. The 'spirflower' is a case in point. Flowery things are probably universal, in that it makes sense for sessile life forms to entice mobile ones to help with procreation. A flower is just an advertisement. There is no need for them to look like Earth flowers though: any form might do, I guess. The spirflower has two brightly coloured blade-like leaves in a double spiral, with small bulbs on top that exude the reward for landing there (while secreting some sexual cells, of course). Here is one in a close-up, done with Vue.
Sunday, 15 November 2009
Click to enlarge; © Alex Ries
This one image speaks volumes. The first is that Mr Ries really knows his business as an artist (I wish I could paint in such a assured manner). Obviously, you can also see that it is an intelligent species (or at least it has intelligence in the toolmaking sense, and I am not certain that that is enough to qualify). Something else that struck me is what the body plan of the Birrin reveals about its planet. There is no indicator of scale, but the objects and choice of perspective suggest that the Birrin is at least one meter tall. It must live on a low-gravity world. I think so because its legs are rather spindly and stick out sideways, instead of being held vertically underneath the body. On Earth such limb positions only work for animals that are rather small, up to the size of a coconut crab, but most animals with such limb designs are smaller that that.
The reason for this is that gravity affects animals of different sizes in different ways, a subject known as scaling. It is less complex than it sounds. Suppose you make an animal twice as large in the sense that its height, width and breadth are all twice the original amount. The large one will weigh 8 times as much; that is because weight relates to mass, and mass relates to volume, and volume relates to length by a power of three. Now the cross area of its legs will be four times as much as in the original animal, because area relates to length by a power of two. The strength of legs is relates to their cross section, so what we have is an imbalance: the animal's weight has increased more than the strength of its legs. The solution? Increase the cross sectional area of the legs out of proportion. That's why elephants have thick columnar legs held under the body, and spiders have thin ones that can stick sideways. Can you have a large animal with spindly legs sticking sideways? You can, on a low gravity planet. Alternatively, the material the animal is made of are incredibly strong (how about a skeleton of biological carbon nanotubes?). The Birrin doesn't look very small but has thin legs, so I assume it lives on a low gravity world. I wonder what really small animals look like: hair-thin legs?)
Anyway, I cannot resist plugging the concept of 'centaurism' once more; the Birrin looks like its manipulative front legs have evolved from walking legs, so there we are again...
Here is another fine animal, one with (largely) radial symmetry. It is good to know that tetropters and spidrids are not the only animals in the fictional universe with radial symmetry. They have their counterparts in the known universe, with anemones and starfish and the like, but sadly we know of no animals walking around with any degree of elegance. I like the anatomical details of this one. I have no idea whether or not it is supposed to live on the same world as the Birrin.
What an intriguing shape. It is probably so intriguing because it is not immediately obvious what part does what, or why it is where it is. That is what makes it convincingly alien, I think. Is it a passive floater? It has a rather large bladder, apparently larger than a mre swimbladder would require. What are the membranes for, I wonder; perhaps they are a sea anchor to make it fave waves head-on?
This one I found on Deviant Art. This animal is an excellent example of convergent evolution. I do no just mean that it is similar in some ways to seals, turtles or plesiosaurs, with its apparent 'swimming with wings' design. I was thinking about 'convergent speculation', meaning that it resembles a design that someone else has also come up with. In this case that someone is me, but you see this happening everywhere where people sit down with a sketch pad and create new animals (while writing this I hesitated a bit with the word 'create', because creationists have tainted it to such a degree that it is difficult to use without evoking wrong connotations). The animal I was thinking about follows:
Click to enlarge; © Gert van Dijk
See the resemblance? Mine was just a very rough sketch, but it conveys the general idea; they are 'AYUS' (As Yet Unnamed Species) from the 'Fishes IV' class. There are differences too, such as the apparent size differences, with mine at about a meter, and his perhaps at humpback size. But look at the similar design of the mouth parts. Before anyone thinks otherwise, I am not saying that either one of us took the idea from each other's work. That cannot have been the case anyway, as mine was done over 10 years ago and has never been published.
It's a simple case of convergent speculation! Of course there are clear influences to be seen in some people's work pf others'ideas, I think that Alex' work looks all his own. Anyway, there are a limited number of biological principles to go around, so all of us tend to arrive at the same ones, having all been subjected to similar ideas. Luckily, there are infinite ways to arrange such similar ideas (and if that sounds a bit like Mr Spock, so be it).
Be certain to have a look at the websites I mentioned, as there is more to see there. But not enough to satisfy the appetite for more... I hope Alex Ries will be successful in getting his book published, because his work makes me very curious to see more of it.
Saturday, 7 November 2009
In other words, neural control is probably the prime difference between animal locomotion and man-made machinery. 'Control' goes much further than just standing upright or thinking of where you are going. It also affects leg design to a very important degree. Have a look at the following graph.
This is the result of one of my Matlab programs to animate fairly simple legs. First suppose that a leg is suspended, so when it moves its hip will stay in place and the foot will described a movement in the air. The blue dots show 100 points of just such a cycle: in this case, 50 points describe how the foot moves forward (to the left) through the air, and the bottom 50 points describe the part where the foot is supposed to go over the ground. In that section, the foot has to move the exact same distance from dot to dot, and the movement should be in a perfect straight line (anyway, if you do it this way the animation is much easier). The brown lines show a variety of ways how you could position a leg with just three 'bones' in it (thigh, leg and ankles) to link up the same hip and foot positions. Obviously, there is an infinite choice here, and in biology the nervous system decides on the best one, taking into account anatomy, gravity, lengths of bones, etc.
If you haven't got a brain, such as holds for mechanical designs, but you want a walking leg nevertheless, you will have to find a way to get the leg to move through a similar movement arc as shown in the figure above. In short, the degrees of freedom a nervous system can easily deal with must be abolished altogether. The trick is therefore to start with a defined movement provided by a motor, such as a rotary movement, and to devise a system of links and levers to end up with a foot moving though a suitable path. Some people actually solved that problem. Let's have a look.
One of the first must be the Russian engineer Chebishev, brought to my attention by Pavel Volkov (thanks Pavel!). Pavel also pointed me towards the video shown above, an animation of how the system was supposed to work. Here it is in its YouTube home if you prefer that. I have no idea of how this engine was supposed to be powered.
The impressive machine ambling along on the video above is a strandbeest. Theo Jansen's 'strandbeesten' (which is Dutch for 'beach beasts') must be the most famous of this type of walking machine. His designs are marvels of engineering as artistic wonders as well. They have to be seen to be believed (before anyone asks, no, I have never seen them with my own eyes, which is something I should rectify one day).
Personally, I have found that I had to watch it, and others like it, quite a few times before I began to understand how the legs move. Apparently Mr Jansen made use of an evolutionary approach to work towards the optimal proportions of all the struts and links that make the legs behave as necessary. If you type 'Jansen linkage' into Google, you will find that many people are equally fascinated, so the 'Jansen linkage' seems, like any good meme, to be spreading and evolving. If you wish to se it in more detail, have a look at this site, where you can even play with design to see if you can improve the output. His devices have been copied in wood, cardboard, and other materials. There are Lego examples as well.
The one shown above is made from wood. It has a very clever gear system that ensures that only one leg is off the ground at any time. The YouTube text says that this is a stop-motion animation. Its website is here.
There are other approaches as well, such as the Klann linkage. It results in a more spidery walk, as can be seen by a direct comparison of the two linkage systems. This system has spawned several large mechanised walkers, to be found through Google or through the Klann site.
Do these designs lend themselves to 'biologification'? In other words, could I or someone else use them for a fictional animal? I can think of no reason why it should be impossible to have a pantograph-like leg. But why would you want a leg that can describe only one movement? All adaptability and all flexibility are thrown out of the window. If you throw in a fairly decent nervous system instead, you can solve the walking problem and do much more besides. So no, I do not think that this is a mechanical design that would work well in biology.
But that doesn't stop me admiring and enjoying the ingenuity of designs such as the strandbeesten!
Saturday, 31 October 2009
So imagine my surprise and delight when Josh, a regular commenter, alerted me to a new project: the Morae River by Brynn Metheney. Browsing through the Morae River website revealed that the site came into being about half a year ago, so it is fairly new. What is it about? Well, one of the first pages shows a map of a large geographical region around the river Morae. The area covered is 300,000 square miles. After conversion to a more sensible length measure this conforms to an area of about 770,000 square kilometers. The closest match for countries I could find was Turkey. That is a big playing ground. This shouldn't pose too many limitations to the designer's creativity, as there are mountains, plains, hills, swamps, an estuary and a sea. I did not immediately spot a desert though, but there might be one. The site discusses animals, plants and biotopes. Let me show a few examples. There are more on her site, so be certain to visit it.
The first animal I will show here is a recent addition to the site: the 'Sabulo'. It is described as a fish. Take a good look: that does not look like a contemporary Earth fish, does it? Its body plan is neither that of a teleost fish nor that of a cartilaginous fish. And it also doesn't look like any of the various extinct classes of 'fish' on Earth. I see no gill slits and no clear gill covers, and there are three pairs of paired fins, looking suspiciously like redesigned legs. Are we not on Earth? By the way, I have no objections at all to using the word 'fish' in a loose sense. On Furaha there are six classes of 'Fish', all of which have proper names such as 'Clavifluitati', which probably explains why they are usually labelled 'Fishes I' to 'Fishes VI' instead. The English language is biologically extraordinarily careless with the word 'fish' anyway: apart from animals such as salmon, there are crayfish, cuttlefish, starfish and shellfish. This motley collection makes you think that the word 'fish' originally may only have meant 'edible water animal'.
Here's another fine drawing: a blue-throated hulompolus. I love the contrast between the gaudy dewlaps and the otherwise relatively boring dull gray exterior. The 'BTH' is a reptile according to the text; it lays eggs, but a reptile with external ears? Its hearing is said to be good, so it having ears is no mistake. Obviously, we are not in Kansas anymore. So where actually is the river Morae? Is this alternate evolution on Earth, or are we somewhere else entirely?
A quick glance at the two animals shown here betrays how they get their calorie intake: these animals kill for a living. They are red-tailed mardiks. The scars on the nearest animal, with its one blinded eye, are a brilliant idea. I think that this is the first time that I have ever seen a recognisable individual of an imaginary species instead of just the general one. I wouldn't be surprised if people pick up on this notion and start adding things such as nicks to ears and broken teeth to their creations from now on. The mardik looks like a mammal and might be one; the spines and the apparent bony scutes on its neck could be explained away while still keeping it an Earth mammal, but then again, it might just be called a 'mammal' as shorthand for its general form. An other word might be used, such as 'mammaloid', but that sounds pretty horrible. 'Mammalian' could do; I once came up with 'mammalien' as a pun to use for a similar purpose. Anyway, none of this solves the riddle of where and when to situate the river Morae any smaller; quite the contrary.
The author prefers to keep us in the dark regarding how all of this fits together. I do not think this makes a big difference. After all, one of the tricks of a good science fiction novel is that it should leave you wanting to know more about the world you've just read about. Speculative biology is no different. A certain way to spoil that thirst for more is to write lengthy essays explaining absolutely everything about how a particular world works. That gets boring quickly. The river Morae doesn't do that at all. In fact, it is at the opposite point where I think I haven't seen enough, so I want more! Luckily, there are remarks in the text suggesting that there more is to come. Good! You can already order a book, published by using one of these novel 'lay out your own book and we print it' firms. It looks attractive, and I will certainly order one, right after posting this blog entry.
Saturday, 24 October 2009
And now for something rather different. I found the website of Mike Bruinsma rummaging though other sites' links. His site informs me that he is a professional designer and illustrator. Luckily, his interests include 'Character / Creature design', under which heading you will find the following images, and more besides. I have no idea whether there these animals have a common background story or whether they all stand on their own.
I like this hunting scene. There might be some common parentage between the hunters and the hunted in view of their jaw design. Then again, the large hunters appear to be bipedal with a basic tetrapod design, whereas the small creatures in fact seem to be running on three legs, as far as I can make out their anatomy. It seems like they have one strong hind leg and two more slender front ones. The front ones move in unison. Well, well, I should have incorporated these when I discussed tripedal walking designs in a previous post.
A head... Clearly, Mr Bruinsma has a sense of humour and is not afraid to show it. Too many people take speculative biology too seriously, and then it quickly becomes boring. The whole field is an intellectual exercise, nothing more. Like science fiction it should be entertaining (OK, as well as thought-provoking).
Another head. Now this one immediately makes you wonder what the gaudy colours are for. Sexual selection immediately comes to mind. Many things in Earth biology that do not make sense from a simple and austere view of 'fitness' turn out to have to do something with sex, and why should the rest of the universe by any different. I wonder what the other sex(es) look like?
I will end with this one, because it is my favourite, not because there aren't any more. There are! It is a bit difficult to say why I like it so much. Is it because of the relative calm of its position or the calm composition? Its well-designed body position? By the way, I suppose everyone immediately saw that we are dealing with a pentapod here: there is one big leg at the aft end of the body and two pairs of legs very close together at the front. One pair of these legs hold the body in position by grasping the branch, while the other pair is held in the air. Are these dextrous manipulators? Is this another example of centaurism? It seems so. I guess I do know why I like this one so much: it's biologically interesting and artistically very pleasing. The only thing missing is more of the same!
Tuesday, 20 October 2009
First, here's one for Anonymous. It is a tripod walker with two legs moving in phase and one acting on its own. In this case, the leg moving on its own is the front one rather than a hind one. Please note that the hind legs do not just move in a pure front-to-aft direction, but swing in a circle. That's a result of their radial design. At any rate the body should swing to kep the centre of gravity balanced over the legs, but that hasn't been programmed in yet.
And just for fun a leggy spidrid. NOT a spider! A SPIDRID!
Sunday, 18 October 2009
Why not? To obtain a first look of how a pentapod (five legged) animal might possibly look like, I adapted the Matlab program I had used to animate the octapods on my site. (you will find them on my site: go to it here, chose the yellow 'land' icon, and then go to the 'walking with...' icon). It was simple job to change the number of legs to five. Obviously, there is gait to consider: what should the phase differences between the various legs be? The first choice would be to have a 'skipped walk' , in which one leg is at 0 degrees (the same as 360), and the others are at 72, 144, 216 and 288 degrees. It's just a question of assigning a phase to a particular leg. Anyway, there it is.
I then thought I would experiment with legs moving in pairs as well. Of course, there will be one left to move on its own, so what you get might be two pairs and a single. So here we go:
Odd? Indeed. There is an animal on Furaha with a similar gait pattern. I do not remember mentioning 'secondary bilaterally symmetrical neospidrids' before, even though they are quite common. What happened is that some spidrids, octapods and therefore without a left/right symmetry axis, started lifting some of their legs to catch prey. They used three legs for this purpose, so these three 'raptorial appendages' are an example of centaurism. This leaves them with 5 to stand on. This induced bilateral symmetry, but with the plane of symmetry going through one leg!. This leg is in the median plane, and is noticeably bigger and stronger then the others. It is the neospidrids' jumping leg, providing most of the force of its jump. The adjacent legs help with propulsion and with steering the animal while jumping. In slow walks you get a gait more or less as shown above.
You might think that no animal on Earth walks like this, but you would be wrong. True, there are no animals with five locomotory legs, but there are several using five appendages for locomotion. The following video, from YouTube, shows one. Have a look at the adult kangaroo. Moving slowly presents kangaroos with a odd problem: their legs aren't exactly designed for that, and for some reason they do not alternate the movements of their hind legs. These move in a pair, and so do the front legs. It is the tail that does the trick. Look very carefully: when the hind legs are swung forwards, the kangaroo rests on a tripod formed by its tail and the two front legs. This tripod alternates with a phase in which the tail and front legs move forwards while the animal rests on the stable area formed by the large feet. A pentapod on Earth!
And to make it even more wonderful, consider the tail. It is of course a stack of vertebrae, but it must take some strength to keep it from buckling. Isn't this an example of 'walking on tentacles', in particular the Mark II Walking Tentacle?
Now it is time to reduce the number of legs to three. Quadruped animals lose a leg if unlucky, and there are many videos to be found on the internet of dogs and cats who seem to manage quite well as three-legged animals. But I know of no animal on Earth that uses three similar legs for walking, and for once there seem to be nu Furahan alternatives either, or at least they have not been discovered yet. So I whittled down my 'octapod' design to only three legs, and introduced a phase difference of 120 degrees so the legs are not in phase. Here it comes:
Could it walk? Certainly not as shown here. This model was designed for octapods in which there are always legs on the ground, which means the legs can be placed wide apart. If you have just two legs, or three for that matter, the feet should be placed much closer to where the centre of gravity projects on the ground. Just try to walk with your feet at least 60 cm apart and see where that lands you. I could adapt the program, and may, but that will take time.
The only recourse left are the worlds of science fiction and of mechanics. In SF a 'tripod walk' can only be associated with one thing: Well's War of the Worlds, and the tripod mechanical marvels in which the Martians strode around eradicating anything human. For good engineers they were remarkably poor biologists, but never mind that. So how did the tripods actually walk? Somewhat to my surprise I could not easily find clips of the Spielberg movie. Why is this? Aren't there any? Surely Spielberg's computer people solved the problem of having them walk in a believable fashion? I did find a very entertaining video made by 'mrgrotey' of a tripod as shown in Jeff Wayne's adaptation of War of the Worlds. Its original location on YouTube is here, but there is a more elaborate website as well. Have a look:
Before the tripod starts to dance, you will see it walk. Note that it moves with 120 degree phase differences between its legs. Is that they only way to move with three legs? Not really. You could have two legs moving as a pai with the other one as the odd man out, or have all of them move together. Someone has already worked that out. On Peter Balch' site I found three animation showing just that, and here I will only show one, so you will be tempted to pay his site a closer look. The support diagrams are very nicely done.
Note that the feet are planted very close to the midline, so there should be no problems with keeling over, or at least none that cannot be solved by a suitable brain, biological or otherwise. It seems to be the only design in which the legs are not attached to the body in a triangular pattern but along a line.
Finally, you may wonder whether someone has built a machine that walks on there legs. In fact, one such has been shown earlier on this blog, but I have found another. Here is where I found it. Unfortunately, I can't seem to copy it for you here, so you should follow the link. . You can see that the designer chose to have the legs wide apart, so for the beast not to fall it has to move the projection of its centre of gravity close to the legs that remain on the ground. Only then can it afford to move the third leg. The only other solution would be to actually build something like the tripod animation above, but I am certain that taking care of what an animal brain does naturally (sensing, adapting and correcting) is extraordinarily difficult to do with a computer. So the little machine shown through the link is quite brilliant: it is a walking tripod machine!
Sunday, 11 October 2009
Marc Boulay and Sylvia Lorrain, who were responsible for my invitation (merçi!) and who live nearby, were kind enough to help me with the French text. Just as well, as it turned out, because one my translation of the word 'seasucker' (you will find them on the 'swimming with...'page) in its literal form turned out ot have unfortunate connotations. And no, I will no mention it here either. Doing the talk in French was quite an adventure, but I think it well fairly well.
During the visit Marc and Sylvia were kind enough to invite me to their home, where they demonstrated the process of designing animal shapes in ZBrush as well as texturing them. It is clear to me that this process requires considerable expertise, and also that they have mastered it. Anyone interested should keep an eye on their sites.
By the way, all this traveling means that I haven't had much time to work on this blog (or on anything else). Still, I am collecting material on walking with odd numbers of legs. 'Odd' here is used as the opposite of 'even'; most what you find here is odd in the other sense anyway.
Sunday, 27 September 2009
Those of you who visited the sites of Marc Boulay and Sylvia Lorrain may have noted that the bulchouk, a decidedly Furahan avian, has flown onto their sites. Just for fun I will repeat some of the images here. The bulchouk itself is only visible on my site as an illustration on a book cover, so here is a bit more of it for you to see.
The next stage was that Marc Boulay used ZBrush to model it in 3D, resulting in images like the following:
And then Sylvia took care of the textures and colouring and put the model against a good backdrop:
I am also now fooling around with Zbrush, which is fairly easy to get into. But if you want to see how it ought to be done, Marc has put a video on his site on which you can see how he modelled the bulchouk starting with a few simple spheres. Just go to his site, click 'FUN' on the menu at the top. Alternatively this will take you there directly (but you will miss the Triceratops!). Just click on the play button on the second window, and be prepared to be amazed.
Sunday, 20 September 2009
So, are there interesting mechanical contraptions out there that deserve to be 'biologified'? (I just invented that word but checked it on Google to be certain. Unfortunately, I was not the first: 'biologify' has 3 hits and its derived noun 'biologification' already has 91. Oh well...).
Well, the result of my search is a bit less dramatic than held for the flying animals, but there are some intriguing inventions out there. If you type in words such as 'walking machines' or 'robot insect' into Google, you will find many hits. Most concern toys with usually a high number of legs, of which only a few are lifted at a time. Most are not at all sophisticated in the sense of having integrated sensory and motor systems with balancing reflexes. No neural control at all, sadly. Instead there is just a motor and some mechanical bits and pieces that turn a rotary motion into steps. If you look at them, you realise how complicated and advanced biological walking really is. Still, that does not mean that people cannot have fun with these machines, and watching them is good fun as well. Just have a look at the following clunker:
I found it on YouTube, where it is labelled as a walking machine at "Burning Man '07" You can see that there are at least four legs on the ground at any time, so no delicate balancing tricks here. There doesn't seem to be much in the way of a suspension either, so it might pay to bring a soft cushion.
A more advanced machine is the so-called 'walking tractor'. From what I read, it was a design by a Finnish company meant for the logging industry, but the company apparently no longer exists. You can see they followed the double tripod design, in which three legs are always on the ground. This one apparently had advanced computerised controls. Here it comes:
A walker that really is beginning to look like an animal is the 'Big Dog' by Boston Dynamics. It is supposed to help soldiers cross difficult terrain. A very convincing demonstration occurs halfway in the video: someone kicks it, and it obviously has the reflexes to deal with that. If it steps in a hole, it can even deal with that without falling too. It is lengthy, but worthwhile:
I found it extremely impressive. Well, for a machine, that is. It is not impressive for an animal, which shows how much cybernetics still have to catch up...
None of these machines provide new inspiration in the sense of something that biology hasn't come up with yet. Surely there is something of interste for those who do speculative biology? Yes, there is: in the first place, machines such as the clunker shown above do hold some interest, as their legs work as 'pantographs': there is a system of bars linked together with movable joints, and no biological leg works like that. I will keep that subject for another entry, and that will also deal with Theo Jansens 'standbeesten'.
I will close with something for which I do not think there is a biological analogue, and I rather doubt the design idea lends itself will for biologification. It is a tripod walk. You will probably be disappointed know, seeing that tripod walkers go back as far as HG Wells in 'The war of the worlds'. (By the way, walking with odd numbers of legs might also merit a blog entry one day: there are pentapod walkers on Furaha, not to mention Epona!) But the design here has a twist. Almost literally, in fact. Its home page is here It is very creative and very crazy at the same time, so I cannot help but like it! Does anyone think it makes sense for an animal to move like this?
Sunday, 6 September 2009
Saturday, 29 August 2009
I like to use the word 'ballont' as a general term for lighter than air flying forms, and have devoted some attention to ballonts previously, once while discussing Edd Cartier's work, and once in more general terms. Ballonts are generally large; how large they have to be depends largely on the density of the gas they are flying or floating in. The denser the external gas is, and the lighter the gas inside the ballont is, the more you can lift. It is therefore no wonder that most science fiction authors who come up with ballonts drop them in very heavy atmospheres, such as in gas giants. The more I think about it, the more I am convinced that I cannot really get away with ballonts on Furaha. I have made the atmosphere denser than on earth, but it still is no Venus. In the end I will probably have to restrict ballooning lifeforms to small balloons for seed dispersal, and write off the truly large beings altogether. A shame, but what can you do? The laws of physics yield for no one.
Anyway, back to ballonts. My inventions were rather passive, in contrast to the inventions of other inventors, who did not hesitate to turn their creations into actively moving animals. There are even active predators out there. The reason mine were designed as relatively passive animals was that I always worried about the balance between lifting capacity and 'cargo weight'. The 'zeppeloon' on the Furaha site is a good example. In this context, any part of the animal that does not contribute to lifting capacity is cargo: eyes, jaws, a brain, a gut, flippers and muscles to move those flippers. The fewer of those you have, the more likely you can get away with a ballooning design. Besides, how believable are flippers anyway: wouldn't they need to be incredibly powerful to fly against the wind?
Those of my colleagues who design actively moving ballonts seem to prefer manta-like shapes, to the extent that a ballooning manta is now more or less the staple image of science fiction. Man-made balloons use propellors and the like for propulsion, making use of the one invention that is taboo in biomechanics: true rotation. So are there no mechanical manta-like balloons?
As the above video proves, there is one! The German firm Festo seems to revel in amazing biomechanical wonders, and they could not resist making a flying manta balloon. Here is their website. Just click on the various entries saying 'Projekte' to find more gems. Amazing, isn't it? This thing is really flying inside a building, which makes you think that perhaps I am too critical about ballonts: if this thing can fly on earth, couldn't a ballont fly on a terrestrial planet as well? I wonder... But what would a breeze of wind do to it?
The next question is why all my fellow 'exocreators' settled on the manta shape. After all, among swimming lifeform it is not exactly the most common design. In fact, manta shapes form a definite minority. Fishes and squid are the norm in Earth's oceans. So can balloons be propelled in such a way that they resemble the most likely shape, that of a fish?
And once more the answer is yes... This particular film was not derived from Festo, but found on YouTube; here it is on the YouTube site. Once we're at it, some animals swim with flippers. Can you have a balloon propelled by flippers?
Yes, you can, and Festo did it, with their 'air penguin'.
And an 'air jellyfish'? No problem for the people at Festo.
Enough for today, I should think. My conclusion is that there is no need to shape ballonts as manta's. I rather like the 'air jellyfish' design. For those who want yet more, there is an intriguing clip on YouTube showing a balloon lifting a young woman strapped underneath. She moves about with wings attached to her arms in a hangar. As the commentary rightly says, what would happen in a breeze? I guess that the rather neat idea illustrates the limits of ballooning on a terrestrial world...