In other insect news, a case of life imitating (well, at least acting similar to) network transmission protocols:
This feedback loop allows TCP to run congestion avoidance: If acks return at a slower rate than the data was sent out, that indicates that there is little bandwidth available, and the source throttles data transmission down accordingly. If acks return quickly, the source boosts its transmission speed. The process determines how much bandwidth is available and throttles data transmission accordingly.
It turns out that harvester ants (Pogonomyrmex barbatus) behave nearly the same way when searching for food. … A forager won’t return to the nest until it finds food. If seeds are plentiful, foragers return faster, and more ants leave the nest to forage. If, however, ants begin returning empty handed, the search is slowed, and perhaps called off.
From Moby Dick, chapter 42, “The Whiteness of the Whale”:
Is it that by its indefiniteness it shadows forth the heartless voids and immensities of the universe, and thus stabs us from behind with the thought of annihilation, when beholding the white depths of the milky way? Or is it, that as in essence whiteness is not so much a color as the visible absence of color, and at the same time the concrete of all colors; is it for these reasons that there is such a dumb blankness, full of meaning, in a wide landscape of snows – a colorless, all-color of atheism from which we shrink? And when we consider that other theory of the natural philosophers, that all other earthly hues – every stately or lovely emblazoning – the sweet tinges of sunset skies and woods; yea, and the gilded velvets of butterflies, and the butterfly cheeks of young girls; all these are but subtile deceits, not actually inherent in substances, but only laid on from without; so that all deified Nature absolutely paints like the harlot, whose allurements cover nothing but the charnel-house within; and when we proceed further, and consider that the mystical cosmetic which produces every one of her hues, the great principle of light, for ever remains white or colorless in itself, and if operating without medium upon matter, would touch all objects, even tulips and roses, with its own blank tinge – pondering all this, the palsied universe lies before us a leper; and like wilful travellers in Lapland, who refuse to wear colored and coloring glasses upon their eyes, so the wretched infidel gazes himself blind at the monumental white shroud that wraps all the prospect around him. And of all these things the Albino Whale was the symbol. Wonder ye then at the fiery hunt?
Many birds have a compass in their eyes. Their retinas are loaded with a protein called cryptochrome, which is sensitive to the Earth’s magnetic fields. It’s possible that the birds can literally see these fields, overlaid on top of their normal vision. This remarkable sense allows them to keep their bearings when no other landmarks are visible.
But cryptochrome isn’t unique to birds – it’s an ancient protein with versions in all branches of life. In most cases, these proteins control daily rhythms. Humans, for example, have two cryptochromes – CRY1 and CRY2 – which help to control our body clocks. But Lauren Foley from the University of Massachusetts Medical School has found that CRY2 can double as a magnetic sensor.
This futuristic method is based on a centuries-old observation that electric fields can do funnythings (videos) to flames, making them sputter and even snuffing them out.
The researchers’ early-stage prototype consists of a 600-watt amplifier hooked up to a electric beam-shooting wand, according to their presentation at the American Chemical Society meeting earlier this week. In tests, they were able to quickly zap out flames over a foot high.
I look forward to the day when I can dial 911 and get the ArcAttack guys over to put out the blaze!
Mind-boggling stuff like this is why I keep reading science journals. We can already use photons to push and pinch things with their tiny mass (amazing enough), but new research is underway in how to pull with photons:
Light is pushy. The physical pressure of photons is what allows for solar sail space missions that ride on sunlight, and what allows for dreams of lasers that will push those sails even faster. And light can trap objects, too: Optical tweezers can hold tiny objects in place. Pulling an object with light, however, is another matter. … Jun Chen’s research team says that the key is to use not a regular laser beam, but instead what’s called a Bessel beam. Viewed head-on, a Bessel beam looks like one intense point surrounded by concentric circles—what you might see when you toss a stone into a lake.
From the Journal of Experimental Biology comes news that caterpillars are able to force air through their bodies to ‘whistle’ as a defense mechanism when they’re spotted by predators. These aren’t exotic bugs, either: they can be found all over the U.S., even here in Austin, Texas (guess I’d better listen carefully next time I’m in the backyard). From the Natureabstract:
When under attack, walnut sphinx caterpillars (Amorpha juglandis), whistle. An 1868 Canadian Entomologist paper, “Musical larvae,” first reported these shrieks, but their purpose wasn’t clear.
Jayne Yack at Carleton University in Ottawa, Canada, and her team now show that the whistle, produced through openings along the body called spiracles, is a defence against predators. Simulated attacks with blunt tweezers caused the caterpillars to pull their heads back, forcing air through two of the spiracles in a succession of squeaks.
Could the tastiest nectar, even close by the hives, compete with the charms of a liquid so abundant, so vibrant and so cloyingly sweet? Perhaps the conundrum raises another disturbing question: If the bees cannot resist those three qualities, what hope do the rest of us have?
The merging of nature and human activity harks back to earlier Japanese tradition, according to art historian Toshio Watanabe of the University of the Arts in London, who is lecturing at the gallery. The famed woodblock landscapes of Japan usually depict human endeavour coexisting with nature — unlike Western art, in which nature is an awesome, sublime force that often excludes or overpowers humans. Even in Hokusai’s famous 1832 painting The Great Wave off Kanagawa, Watanabe explains, the people don’t look panicked and no boats are overturned: “The picture is as much about the energy of the boatmen as the waves.”
Above video from the show: Snow, an interactive installation of feathers created by Yoshioka Tokujin.
There’s lots of conspiracy theory nutjobs talking about the HAARP research project lately (even Hugo Chavez is throwing his hat in), so the allegations of death-ray and mind control weapons tinges this science news a bit, but there’s something kind of beautiful about being able to generate your own version of the aurora borealis:
Artificial auroras can be created using an array of high-frequency transmitters. Researchers have previously done this by pumping a 3.6-megawatt beam of radio waves into the ionosphere, a region of the atmosphere a few hundred kilometres above Earth’s surface. The beam was powerful enough to break electrons free of their parent atoms, creating an artificial aurora similar to that of the Northern Lights.
It’s certainly an unusual way to leave your mark on the world, and I presume it’s harmless, given that we’re being constantly bombarded by the same kind of energy raining down from space (right?). Just so long as they aren’t cutting their way into heaven a la Lord Asriel in The Golden Compass, I guess…
(Found in Nature, which cites research in Geophysical Research Letters, but I can’t find the cited article anywhere. Maybe it was pulled? Aha, a conspiracy!)
A paper in Nature Photonics describing the waveplate mechanism found in the eye of mantis shrimp (stomatopods). These amazing critters can see hyperspectral color ranging from the infrared to the ultraviolet, can perceive different planes of circular polarized light, and have eyes that operate and dart about (saccade) independently. This paper is basically demonstrating that man-made material science has a lot to learn if we want to catch up with nature’s technology.
Personal side question: what are these shrimp on the lookout for that’s led to such a sophisticated eye??
[Geneticist Danny Brower] explained that with full self-awareness and inter-subjectivity would also come awareness of death and mortality. Thus, far from being useful, the resulting overwhelming fear would be a dead-end evolutionary barrier, curbing activities and cognitive functions necessary for survival and reproductive fitness. […] In his view, the only way these properties could become positively selected was if they emerged simultaneously with neural mechanisms for denying mortality. […] If this logic is correct, many warm-blooded species may have previously achieved complete self-awareness and inter-subjectivity, but then failed to survive because of the extremely negative immediate consequences. Perhaps we should be looking for the mechanisms (or loss of mechanisms) that allow us to delude ourselves and others about reality, even while realizing that both we and others are capable of such delusions and false beliefs.
Seeing is believing — a naive assumption in the case of an illusion device proposed by Lai and colleagues at the Hong Kong University of Science and Technology, and described1 in Physical Review Letters. The new device has the power to ‘act at a distance’ and therefore covertly alter an object’s appearance such that it has no apparent physical connection to the light scattered by the object — although this becomes increasingly difficult to achieve the farther the illusion device is from the object. Lai and colleagues1 outline a mathematical formalism proving that it is theoretically possible to grab the rays of light emitted by a given object and to reconstruct them so that they seem to come from a completely different object.
Using metamaterials with refractive indexes less than zero to disguise the origin or content of reflected light. Not sure that I entirely understand this idea, but it’s sort of like the fabled “cloaking device”, except that instead of rendering an object invisible it actually renders it as a different object. Things will be weird fifty years from now.