Nature's Children

[Mark]

In the previous page I linked to an 85 and 96 tentacled octopus, and I came across this guy which is another one with a strange leg count.
"Until Henry, the most famous six-legged octopus was one that appeared in a 1955 B-movie, 'It Came From Beneath The Sea.'
As was common of many science fiction movies of the era, the film was made on a shoestring budget -- and designers left off two legs from the creature because of budget contraints." ha
http://www.cnn.com/2008/TECH/03/04/octopus.uk/

[Mark]

Starting at about the 3rd page in Chapter 2 is a very good essay on bats and sound. I really hope all of you will read Chapter Two: "Good Design", it has so many facets and tricky ways particular bats calculate or "read" sound, and so many uncanny sonar analogies to our radar devices, and how their ears work too. I really liked reading it, just give it a try, the first few pages are slow in Chapter 2 but then it really picks up. It's fun stuff. There's a funny historical slant with a radar scientist too.
http://www.terebess.com/keletkult/The_B ... hmaker.pdf

[larry cottrill]

Dawkins writes the way I would always wish to write; i.e. the first principle is clarity. Unfortunately, I do not always achieve this. But then, I am usually in a hurry.

Donald Griffin tells a story of what happened when he and his colleague Robert Galambos first reported to an astonished conference
of zoologists in 1940 their new discovery of the facts of bat echolocation. One distinguished scientist was so indignantly incredulous that he seized Galambos by the shoulders and shook him while complaining that we could not possibly mean such an outrageous suggestion. Radar and sonar were still highly classified developments in military technology, and the notion that bats might do anything even remotely analogous to the latest triumphs of electronic engineering struck most people as not only implausible but emotionally repugnant.
It is easy to sympathize with the distinguished sceptic. There is something very human in his reluctance to believe. And that, really, says it: human is precisely what it is. It is precisely because our own human senses are not capable of doing what bats do that we find it hard to believe. Because we can only understand it at a level of artificial instrumentation, and mathematical calculations on paper, we find it hard to imagine a little animal doing it in its head. Yet the mathematical calculations that would be necessary to explain the principles of vision are just as complex and difficult, and nobody has ever had any difficulty in believing that little animals can see. The reason for this double standard in our scepticism is, quite simply, that we can see and we can't echolocate.

This is a wonderful story -- hilarious, really. Earlier he discussed the spacial perceptions of the blind, their "facial vision". It is no surprise to me that this is an interpretation of what is heard by someone not "sighted". What has always interested me is, what are the differences between the perceptions of a "blind from birth" individual and someone losing sight later in life? The perceptual "universe" of these different people must be quite different: The once sighted person constantly (even if unconsciously) referencing memories of visual properties like color and stereoscopic spacial mapping; while to the congenitally blind, the whole world must be mapped by touches of nearby things and echoes of more distant ones. And also, emitted sounds, of course (smells, too, come to think of it). The newly blind have to learn these as new primary ways of perceiving reality -- but inevitably, it must be like learning a foreign language late in life (in this case, a language that could mean your very survival!). I can imagine a "blind fom birth" person "seeing" the world in stereo "vision" and navigating it accordingly -- but the perception of really small out-of-reach objects must be limited to impossible. On the other hand, his range of "colors" (wavelengths of sound) must be unbelievably keen and discriminating, and perhaps far beyond our "normal" range in the case of many blind individuals. I've always found it astounding that we can hear many octaves of sound, but can see far less than a single octave of light frequencies -- an incredibly tiny sliver of the electromagnetic spectrum. Our ability to see tiny things is a function of the fact that we make use of very short wavelengths.

I really know nothing about the science of perception, except that it is absolutely fascinating. Finely tuned instruments that actually enhance our physical perceptions are really relatively modern -- Columbus did not have a telescope to peer out at the distant shoreline of Hispanola; it hadn't been "invented" yet. (How DID Jonathan Swift know that Mars had two tiny moons?) People survived thousands of years bumbling around without ordinary eyeglasses. The microscope and telescope revealed that reality is not exactly as our unaided sensory perceptions tell us it is. More powerful instrumentation reveals that our ordinary perceptions don't even come close! Yet, those ordinary perceptions are adequate for 99.99 percent of what we experience (at least for the vast majority of us).

The Iowa Legislature just had a bill introduced requiring electric cars to make enough noise at low speeds that the blind will be able to hear them coming from some distance away. How well would this work in the midst of normal traffic noise? (I guess it would depend on what kind of noisemaker you use.)

L Cottrill

[Mark]

I liked these Dawkins passages, the first one reminded me of a previous post I made citing Discover Magazine, and also what they are working with at the Institute for Human and Machine Cognition here in my town to some degree. (See page 2 of this article, read the right column (Reteaching the Brain to Balance)
http://discovermagazine.com/2003/jun/feattongue

Some passages from Dawkins and the bats that I liked ...
"Objects are 'out there'; and we think that we 'see' them out there. But I suspect
that really our percept is an elaborate computer model in the brain,
constructed on the basis of information coming from out there, but
transformed in the head into a form in which that information can be
used. Wavelength differences in the light out there become coded as
'colour' differences in the computer model in the head. Shape and
other attributes are encoded in the same kind of way, encoded into a
form that is convenient to handle. The sensation of seeing is, for us,
very different from the sensation of hearing, but this cannot be'directly
due to the physical differences between light and sound. Both light and
sound are, after all, translated by the respective sense organs into the
same kind of nerve impulses. It is impossible to tell, from the physical
attributes of a nerve impulse, whether it is conveying information
about light, about sound or about smell. The reason the sensation of
seeing is so different from the sensation of hearing and the sensation of
smelling is that the brain finds it convenient to use different kinds of
internal model of the visual world, the world of sound and the world of
smell. It is because we internally use our visual information and our
sound information in different ways and for different purposes that the
sensations of seeing and hearing are so different. It is not directly
because of the physical differences between light and sound."

"Bats may even use the sensations that we call colour
for their own purposes, to represent differences in the world out there
that have nothing to do with the physics of wavelength, but which play
a functional role, for the bat, similar to the role that colours play to us.
Perhaps male bats have body surfaces that are subtly textured so that
the echoes that bounce off them are perceived by females as gorgeously
coloured, the sound equivalent of the nuptial plumage of a bird of
paradise. I don't mean this just as some vague metaphor. It is possible
that the subjective sensation experienced by a female bat when she
perceives a male really is, say, bright red: the same sensation as I
experience when I see a flamingo. Or, at least, the bat's sensation of her
mate may be no more different from my visual sensation of a flamingo,
than my visual sensation of a flamingo is different from a flamingo's
visual sensation of a flamingo."

"What matters here is that some bats
have well-developed muscles attached to the stirrup and to the
hammer. When these muscles are contracted the bones don't transmit
sound so efficiently - it is as though you muted a microphone by
jamming your thumb against the vibrating diaphragm. The bat is able
to use these muscles to switch its ears off temporarily. The muscles
contract immediately before the bat emits each outgoing pulse,
thereby switching the ears off so that they are not damaged by the loud
pulse. Then they relax so that the ear returns to maximal sensitivity
just in time for the returning echo. This send/receive switching system
works only if split-second accuracy in timing is maintained. The bat
called Tadarida is capable of alternately contracting and relaxing its
switching muscles 50 times per second, keeping in perfect synchrony
with the machine gun-like pulses of ultrasound. It is a formidable feat
of timing, comparable to a clever trick that was used in some fighter
planes during the First World War. Their machine guns fired
'through' the propeller, the timing being carefully synchronized with
the rotation of the propeller so that the bullets always passed between
the blades and never shot them off."

"Actually some bats play a trick
that is more interesting than simply emitting hoots of constant pitch
and measuring the pitch of the returning echoes. They carefully adjust
the pitch of the outgoing hoots, in such a way as to keep the pitch of
the echo constant after it has been Doppler-shifted. As they speed
towards a moving insect, the pitch of their cries is constantly
changing, continuously hunting for just the pitch needed to keep the
returning echoes at a fixed pitch. This ingenious trick keeps the echo
at the pitch to which their ears are maximally sensitive - important
since the echoes are so faint. They can then obtain the necessary
information for their Doppler calculations, by monitoring the pitch at
which they are obliged to hoot in order to achieve the fixed-pitch echo.
I don't know whether man-made devices, either sonar or radar, use this
subtle trick. But on the principle that most clever ideas in this field
seem to have been developed first by bats, I don't mind betting that the
answer is yes."

My brother once had a pet bat and it was so funny to watch it's little ears respond like some kind of magical listening devices.
"Another curious trick of horseshoe bats concerns movements of their
outer ear flaps. Unlike other bats, horseshoe bats move their outer ear
flaps in fast alternating forward and backward sweeps. It is conceivable
that this additional rapid movement of the listening surface relative to
the target causes useful modulations in the Doppler shift, modulations
that supply additional information. When the ear is flapping towards
the target, the apparent velocity of movement towards the target goes
up. When it is flapping away from the target, the reverse happens. The
bat's brain 'knows' the direction of flapping of each ear, and in
principle could make the necessary calculations to exploit the information."

"When this diluted sound hits an object, say a fly, it bounces off the
fly. This reflected sound now, in its turn, radiates away from the fly in
an expanding spherical wavefront. For the same reason as in the case of
the original sound, it decays as the square of the distance from the fly.
By the time the echo reaches the bat again, the decay in its intensity is
proportional, not to the distance of the fly from the bat, not even to the
square of that distance, but to something more like the square of the
square - the fourth power, of the distance. This means that it is very
very quiet indeed."
http://www.terebess.com/keletkult/The_B ... hmaker.pdf

And yet another kind of bat tactic.
http://www.youtube.com/watch?v=zgBOH-h6qwk

[Mark]

I recall another ear-dampening creature which has to "cancel out" it's own ears, the cicada.
"The name is a direct derivation of the Latin cicada, meaning "buzzer". In classical Greek it was called a tettix, and in modern Greek tzitzikas - both names being onomatopoeic."
http://en.wikipedia.org/wiki/Cicada

"Cicadas ears are right next to the tymbals. In order to prevent severe over loading of the sensitive hearing structures, cicadas have a special muscle in their ears that actually folds the ear creating a crease. This makes the ear far less sensitive to the high levels of sound produced while the individual is singing."
http://www.musicofnature.com/songsofins ... orial.html

Posted before but good for review.
http://www.healthyhearing.com/hearing_l ... cle_id=765
http://palaeoentomology.blogspot.com/20 ... ss-in.html

[Mark]

I remember one time in college I had a middle ear infection and the room was constantly spinning. I really appreciated science because I was barely able to walk to the clinic and they gave me Antivert, which stopped the merry-go-round effect like a miracle. I too saw the room blurr, everytime I looked or focused on something to the left for example, the whole image would then fly by my field of vision to the right.

"The Wobblers". ha

"Over the past 40 years or so, several thousand people in the United States have lost this sense, due to an antibiotic called gentamicin. One of the drug's side effects is ototoxicity: It can kill the hair cells in the inner ear. Cheryl Schiltz, seen in the photograph on the opposite page, lives in Windsor, Wisconsin. In November 1997, after taking gentamicin for 17 days, she woke up and couldn't stand."I had to crawl," she says. "It was like being extremely intoxicated. I was scared to death."

Schiltz also suffers from tinnitus, short-term memory loss, and vision problems. "It's a living hell," she says. She eventually found solace among other victims of gentamicin, who call themselves The Wobblers, but real relief came only after her physician referred her to Paul Bach-y-Rita.
The results were almost instantaneous. "All of a sudden, I started crying," Schiltz says. "I had forgotten what it was like to see clearly, what it was like not to stagger. It was like the hand of God coming down and touching me." Within half an hour she was standing without assistance. "I was shocked," Bach-y-Rita says. "She learned it almost immediately. I think the reason is that she already had partially trained herself to understand tactile cues. She's been using the contact of her feet on the ground."

http://discovermagazine.com/2003/jun/fe ... :int=1&-C=
http://en.wikipedia.org/wiki/Antivert
http://en.wikipedia.org/wiki/Vertigo_(medical)

[Mark]

In reading about the saga of the afflicted woman who took antibiotics and lost her balance, I hunted down this curious tidbit.

Wobblers Anonymous. "ha"
"All aminoglycosides are toxic to the sensory cells of the ear, but they vary greatly in their relative effects on hearing versus balance. Gentamicin is a vestibulotoxin, and can cause permanent loss of equilibrioception, caused by damage to the vestibular apparatus of the inner ear, usually if taken at high doses or for prolonged periods of time, but there are well documented cases in which gentamicin completely destroyed the vestibular apparatus after three to five days. Since the effects of vestibulotoxicity are physically and psychologically devastating, a Web site has been formed to advise people with gentamicin-induced destruction of the balance system: Wobblers Anonymous at http://www.wobblers.com/ Gentamicin can also impair or wholly destroy hearing. A small number of affected individuals have a normally harmless mutation in their mitochondrial RNA, that allows the gentamicin to affect their cells. The cells of the ear are particularly sensitive to this. Gentamicin is sometimes used intentionally for this purpose in severe Ménière's disease, to disable the vestibular apparatus."
http://en.wikipedia.org/wiki/Gentamicin

[Mark]

Here's a passage out of "The Blind Watchmaker" that interested me.

"To see this, we must develop the idea of Biomorph Land as a mathematical 'space', an
endless but orderly vista of morphological variety, but one in which
every creature is sitting in its correct place, waiting to be discovered.
The space we are talking about is genetic space. Each animal has its
own position in genetic space.
The actual animals that have ever lived on Earth are a tiny
subset of the theoretical animals that could exist. These real animals
are the products of a very small number of evolutionary trajectories
through genetic space. The vast majority of theoretical trajectories
through animal space give rise to impossible monsters. Real animals
are dotted around here and there among the hypothetical monsters,
each perched in its own unique place in genetic hyperspace. Each real
animal is surrounded by a little cluster of neighbours, most of whom
have never existed, but a few of whom are its ancestors, its descendants
and its cousins.
Sitting somewhere in this huge mathematical space are humans and
hyenas, amoebas and aardvarks, flatworms and squids, dodos and dinosaurs.
In theory, if we were skilled enough at genetic engineering,
we could move from any point in animal space to any other point.
From any starting point we could move through the maze in such a
way as to recreate the dodo, the tyrannosaur and trilobites. If only we
knew which genes to tinker with, which bits of chromosome to
duplicate, invert or delete. I doubt if we shall ever know enough to do
it, but these dear dead creatures are lurking there forever in their
private corners of that huge genetic hypervolume, waiting to be found
if we but had the knowledge to navigate the right course through the
maze. We might even be able to evolve an exact reconstruction of a
dodo by selectively breeding pigeons, though we'd have to live a
million years in order to complete the experiment."
http://www.terebess.com/keletkult/The_B ... hmaker.pdf

I suppose the shapes in Pulsejet Land might be likened to this archetype. It's fun to think what might be out there, what's waiting to be born or trying to transmogrify into something else. How strange to think of something as having always been there, allowed for, waiting for it's turn. It reminds me of this episode from The Twilight Zone. ha
http://www.youtube.com/watch?v=o6yP6SijHMU

Anne Francis, James Milhollin and doppelganger
"The After Hours" 6/10/60
http://www.rodserling.com/images/pubAfterHours01.jpg

[Mark]

"The dog uses these extra toes to gain purchase and haul itself along in positions where only the sides of its legs are touching the rock, a fairly common occurrence while wiggling through tight spots. They also help the dog gain additional traction while scrambling around on steep, often slippery cliffs."
http://www.damninteresting.com/?p=743
http://www.messybeast.com/poly-species.html

[Mark]

I was watching a show about dogs last night and I happened to see something about their noses that might be useful in some way in Pulsejet Land. It so happens that they have flaps/valves of a sort in their nose. In this way, they don't interrupt the inflow of scent. When they exhale, they close the flaps and the air is exhausted/gated out to the sides of the nose. Pretty sneaky stuff really.
I was thinking that if you had a Klein bottle, (snorkeled jam jar), and wanted keep an "uninterrupted" pulsating inflow into the snorkel, perhaps on the snorkeled outflow phase the valves could redirect exhausted gases to the side of the funnel intake/exhaust in some way advancing the workings of the design. Anyway, it's something to think about, that is, design a functional dog nose effect on some sort of pulsating combustion device. It might even be fun to try to emulate/perfectly mimic the dog nose itself. Be the first on your block to make a whiffer jam jar or a beagle breather. ha
Here's a bit I found on the net just now to help clarify what's going on. Seems some fluid dynamics boys have recognized a potential for the effect too.

"Dogs and other scenting animals detect airborne odors with extraordinary sensitivity. According to G.W. Settles of Penn State University, who spoke on Tuesday afternoon, aerodynamic sampling plays a key role in this, although little information is available on the external aerodynamics thereof. To this end, he visualized the airflows generated by a scenting dog using the so-called "schlieren technique." He observed that a dog stops panting in order to scent, since panting produces a turbulent jet which disturbs scent-bearing air currents. Furthermore, inspiratory airflow enters the nostrils from straight ahead, while expiration is directed to the sides of the nose and downward. Thus, the musculature and geometry of a dog's nose modulates the airflow during scenting. The eventual practical application of his work is to achieve a sufficient level of understanding of the aerodynamics of canine olfaction to design a mimicking device."
http://www.aps.org/publications/apsnews/199802/dfd.cfm
http://farm3.static.flickr.com/2079/217 ... 74.jpg?v=0

[Mark]

Explosive starts for your interest.

Curious small video at bottom of article.
http://www.thenakedscientists.com/HTML/ ... news/1469/

"The big animals aren't so interesting in terms of drag," said Vogel. "But when you get down to a flea, it loses about eighty percent of potential range to drag. And the optimum launch angle gets lower. In physics class, people are taught that the best angle is forty-five degrees, but when drag is bad, the angle needs to be lower -- you want to achieve some distance while you still have decent speed. Altitude no longer gives much advantage. Thus, in the fungus the launch angle is barely above horizontal," he said.
http://www.eurekalert.org/pub_releases/ ... 072505.php

"The mystery was unravelled by Charles Leach of Oregon State University in the 1970s. He noticed that the spores always flew off at right angles to their leaves - unusual behaviour for a fungal gun. It looked so much like opposite electric charges repelling each other that Leach tried placing an electrode near the leaf. What he saw was remarkable. The spores flew to positive electrodes and away from negative ones. Leach also found that neutralising the leaf with an antistatic gun blocked the launch altogether. Electricity was clearly involved, but how?"

"Eventually the pressure of the juice is so intense that the fruit bursts off its stalk, and flies through the air, squirting out seeds and slime through the rupture hole. The record for a squirting cucumber launch stands at 12.7 metres."

"Other fruits use drying tissues to eject their seeds. On a hot sunny day on heath and moorland, you can hear the snap, crackle and pop of broom and gorse seed pods splitting under the tensions created by uneven drying. Noisy as these flora are, they still only manage to fling their seeds a metre or two. The record launch for this type of explosive drying goes to a more exotic contender, the tropical tree Bauhinia, which powers its seeds up to 15 metres."

" A study in 1986 by Gustavo Romero and Craig Nelson of Indiana University found that a bee which has experienced this violent explosion is highly unlikely to visit another male Catasetum. Henceforth the intimidated bee will visit female flowers only. Here the pollen rubs off, resulting in cross-pollination and a selective advantage for that male - a clear case of explosive aggression paying off."
http://www.newscientist.com/article/mg1 ... ival-.html

[Mark]

http://news.yahoo.com/s/ap/20081010/ap_ ... rk_mystery

[Mark]

http://farm3.static.flickr.com/2242/221 ... a6.jpg?v=0

[larry cottrill]

A small but interesting article on squid jet propulsion -- jet velocities & angles, etc.:

http://jeb.biologists.org/cgi/content/a ... 208/6/1125

L Cottrill

[Mark]

"They then cooled the regions very precisely using a thermoelectric property called the Peltier effect, in which an electric current is used to transfer heat from one end of the element to the other."
"It seems to look a lot like a music box," he says. "You have a drum that rotates and controls the timing. The drum has little bumps all over it. If you rotate the drum more slowly, you get the same notes but they come out more slowly."
http://www.nature.com/news/2008/081112/ ... .1222.html

From the album fairytale

On the firefly platform on sunny goodge street
Violent hash-smoker shook a chocolate machine
Bobbed in an eating scene
Smashing into neon streets in their stillness
Smearing their eyes on the crazy kali goddess
Listenin' to sounds of mingus mellow fantastic
"My, my", they sigh
"My, my", they sigh
In dull house rooms with coloured lights swingin'
Strange music boxes sadly tinklin'
Drink in the sun shining all around you
"My, my", they sigh
"My, my", they sigh, mm mm
"My, my", they sigh
"My, my", they sigh
The magician, he sparkles in satin and velvet
You gaze at his splendour with eyes you've not used yet
I tell you his name is love, love, love
"My, my", they sigh
"My, my", they sigh
"My, my" - sigh
http://www.youtube.com/watch?v=X8wI3IHJ ... re=related
http://www.youtube.com/watch?v=jkV1plyA ... re=related
http://www.youtube.com/watch?v=n6bXul6A ... re=related

"Despite neuroanatomical differences between the avian and human brains, we believe that, at the circuit level, similar computational operations must underlie this form of sensorimotor learning."
http://zebrafinch.org/
http://news.bbc.co.uk/2/hi/science/nature/992538.stm
http://www.bsos.umd.edu/psyc/dooling/pr ... inches.htm

Some tidbits here and there.
"Less dense than air, helium conducts sound faster and emphasises resonances in the vocal tract at pitches that are higher than normal even though the frequency of vibration of the vocal cords changes very little."
http://www.fortunecity.com/emachines/e1 ... tuoso.html