Gecko

In the Mozilla project, gecko is the marketdroid name for NGLayout and XPFE. Mozilla is not netscape, so the still call it NGLayout and XPFE.

I recently discovered something interesting about the common gecko. That is, I guess we've finally discovered how geckoes stick to walls.

In case you didn't know, the common gecko can walk up walls and across ceilings, even if they're made of glass (the walls, not the geckoes). In fact, science hasn't yet been able to create a surface that a gecko can't stick to; they can even stick to molecularly smooth surfaces.

I, like most people I think, always figured they had suction cups for feet or that they excreted some sort of goo, but apparently neither is true. Turns out their feet are incredibly smooth, being covered by several layers of increasingly fine hairs. Their ultra-smooth feet mean that, when they touch something, they're able to put more of the molecules in their feet actually ON the surface than is strictly normal. And molecules, as every ameteur physicist knows, generate a charge when they touch, similar to a magnetic field, that sticks them together.

Why don't we stick to things we touch, you might ask? Because apparently, the human fingertip looks like a mountain range when viewed at a molecular level. So we only actually "touch" things with the tips of those mountains--not enough to generate a significant charge.

But think about it...what if we were to develop very smooth shoes? You'd think it was possible, if the scientists have already made a molecularly smooth surface to try to make a gecko fall on its head. (That's pretty funny; if you think about it, the "molecularly smooth" surfaces must have been even easier for the gecko to stick to.)

Anyway. It's a little tricky outside of theory, I imagine, but I say let's go for it! It's time for the human race to get vertical!

The only problem with humans using "super-smooth" shoes to walk up walls is a matter of surface area/mass ratios. It's a similar problem to the one of why humans can't walk on water even though water striders can do it. A water strider's mass is so low relative to its foot size that the pressure of the foot is insufficient to overcome surface tension; to dupilcate the effect, a person's foot would have to be about 5 square kilometers large. A gecko's feet, compared with the rest of its body, are huge -- each toe is about the relative size of a human's whole foot. So in order to make this work for humans, you'd have to use a whole lot larger area than just the foot, or drastically increase the size of one's foot.

It's still an interesting node about geckoes, though.

I heard this news story on NPR some months ago, with equal amazement, and remember a few additional details. The force which geckoes use is not the electromagnetic, but Van der Waals force. This force is so strong that it was a mystery at first how the geckoes could remove their feet from the surface once they were attached. Apparently, they accomplish this by stiffening the hairs, reducing the area of contact. In essense, peeling their feet off the wall.

Already robot developers are working on prototypes which employ this principle to climb, say, the insides of pipes. This can be taken as a hard-nosed, commercial argument for biodiversity. Who knows what potential advances will never be realized because a species goes extinct before we divine its secrets?

Gecko is a ship in the 1980's computer game Elite. The Gecko is one of the so-called Pack Hunters, which means you'll never encounter one of these on their own. Pack-Hunters are space pirates, and they want to your precious cargo more than anything else. The Gecko carries no missiles, it earns you 5.5 CR in bounty and it never ever carries anything you can loot after blowing it away.

It's also slightly faster than your Cobra Mk I, meaning you cannot outrun it, only blast it with whatever laser you've got for the moment or rely on your hard-earned missiles.

A gecko is a small or medium-sized lizard of the family Gekkonidae, part of the reptile class. Geckos live in warm areas of the world, most usually in or around the houses of humans. Geckos apparently lack movable eyelids, which must make it difficult for them to catch a bit of shut-eye, poor things. They have pads on their feet with backwards-pointing hooky things (ingenious fibres, corrects TheLady, and who am I to argue?), that allow them to cling to apparently smooth surfaces and run around on ceilings, chasing after the insects that are their chief prey.

My cat in Thailand would always scan the areas near the door when he came in, checking if there was a gecko close enough for him to grab as a snack. If there was, he'd jump for it, though more often than not he would only succeed in dislodging a tail, which would flop disconcertingly around on the floor until he ate it. The now-tailless gecko would sport a stump for a few days which would blossom over a few weeks into another tail just like the lost one.

Geckos differ from lizards in that they have voices, each of the 300 species making their own unique sound. By far the most unusual in my not-inconsiderable experience in the tropics is the Thai gecko known as a tookay. These are relatively large - maybe up to a foot in length - specimens with a weird gray squishy look to them. They live outside front doors on porches and balconies. At night this gecko builds up into a large crescendo of sound, letting out a string of tookay cries - up on the took, down on the kay - that will go on perhaps a dozen times, finally ending with a defeated and exhausted-sounding groan. Thai people, always superstitious, count the number of cries, and say that an even number means bad luck. Tookays, once heard, are never forgotten, and if those of us who had heard it were gathered together, our voices would unite in the battle cry of the mighty tookay, squashy gecko warrior of Southeast Asia.

The amazing ability of the gecko to cling to wet glass upside down, as well as a variety of less slippery and hazardous surfaces, without batting a non-existant eyelid, has only recently been properly understood.

Far from having anything so inelegant as hooks (which wouldn't grab glass or metal anyway) on its feet, the humble gecko has developed a mechanism whose engineering ingenuity far surpasses anything we humans have so far come up with.

The bottom of the gecko's foot is covered in millions of microscopic, hair like structures which in turn each split into microscopically fine fibres at the ends. These fibres actually bond with whatever surface the gecko is trying to hang on to and so stop it falling. It is because of this that geckos rarely if ever slide - it is possible, just, to make a gecko fall off of a surface, but it simply cannot slide off without breaking the laws of physics.

There is a slightly more important problem than surface to mass ratio, even were you to stick your feet to the wall (say with a strong electro magnet) you wouldn't be able to hold yourself vertical. The muscles required for this ( In fact most of the major ones) just haven't been built up to cope with that kind of stress, also the taller you are the harder it would be. see torque and Moment of Inertia. The basic idea being that because of gravity and the lever principle taller people will have more force exerted on them. More specifically half the distance from their feet to their center of mass multiplied by their total mass gives the moment of inertia.

For all the tall guys out there this is also what makes it harder for us to do pushups than the short guys.

Geck"o (?), n.; pl. Geckoes (#). [Cf. F. & G. gecko; -- so called from the sound which the animal utters.] Zool.

Any lizard of the family Geckonidae. The geckoes are small, carnivorous, mostly nocturnal animals with large eyes and vertical, elliptical pupils. Their toes are generally expanded, and furnished with adhesive disks, by which they can run over walls and ceilings. They are numerous in warm countries, and a few species are found in Europe and the United States. See Wall gecko, Fanfoot.

 

© Webster 1913.