Tuesday, August 30, 2011

Monday, August 29, 2011


 From New Scientist, a report on a kind of insect chatterbot:
Tim Landgraf of the Free University of Berlin in Germany and colleagues have programmed their foam RoboBee, to mimic the dance. RoboBee is stuck to the end of a rod attached to a computer, which determines its "dance" moves. The rod is also connected to a belt which makes it vibrate. Like a real bee, it can spin, buzz its wings, carry scents and droplets of sugar water, and give off heat.
To program RoboBee, Landgraf took high-speed video of 108 real waggle dances, and put the footage through software that analysed the dances in detail (PLoS One, DOI: 10.1371/journal.pone.0021354). The outcome is "the most detailed description so far of the waggle dance", says Christoph Grüter of the University of Sussex in Brighton, UK, who was not involved in the study.
Despite its realism, RoboBee may not have passed the bee Turing Test: 
In a field outside Berlin, Landgraf trained groups of honeybees to use a feeder, which he then closed. The bees stopped foraging and stayed in their hives. There they met RoboBee, which had been programmed with Landgraf's best guess at a waggle dance pointing to another feeder, which the bees had never visited.
The bees responded by leaving the hive, but returned to their old feeders. For now, it looks like RoboBee persuaded them to forage, but failed to communicate where to go. The team is confident RoboBee didn't just scare away the foragers, as honeybees respond to intruders by stinging, not fleeing...
Its Achilles heel, though, may be a lack of legs: some studies suggest there is a tap-dance element to the dance.
Pictures and clips of the robot can be found on the project's official website

Sunday, August 28, 2011

Encylopedic eggs

This illustration (featuring the eggs of birds and insects, as well as the ornate egg cases of sharks) is from the Grand Larousse encyclopédique. The artist, Adolphe Millot, also illustrated algae, butterflies, feathers, vegetables, and fungi for that same encyclopedia. 

Saturday, August 27, 2011

Storms and tremors

The University of Hawaii has a collection of infrasound recordings, collected from various natural phenomena and converted into audible sounds:
One of the techniques we use to grasp these inaudible sounds is to make them audible through time compression (speeding up), pitch shifting (frequency transposition), or other methods...
Signal processing algorithms were used to make them audible and occasionally pleasant. Many of the sound files are complex, and superpose breaking waves, distant storms, aircraft, and volcanoes.
My favorites are this one from a hurricane, and this one from the Icelandic volcano Hekla.

Link via Bouphonia.

Monday, August 22, 2011

Cestum veneris

This beautiful, bizarre marine invertebrate (cool pictures here and here) is related to the comb jelly:

Wednesday, August 17, 2011

Polyhedral planets

This interesting article describes several hypothetical cubical worlds-- a hypothesized Planet X from 1884; a world of chimeric creatures called Aocicinori (illustrated in tracts handed out at Rice University, Texas, by a "mysterious, well-dressed gentleman" and created by a mental patient); and a cubical version of our own Earth:
Contemporary cosmologist Karen L. Masters also finds the topic of cube worlds fascinating -- especially the atmospheric possibilities. As she explains in Cornell's Ask a Physicist feature, all six faces of the [planet] would boast temperate weather, centralized bodies of water and none of them would feature polar or equatorial weather. What's more, the pointy edges of the cube would actually poke through the planet's atmosphere like titanic mountains.
 I am reminded of the far-future tetrahedral Earth described in a magazine article from 1918:
The world is now the shape of a globe, the shape which gives the biggest possible bulk for its surface, but the inside of the earth is still cooling and condensing, and the internal changes are slowly changing its shape. The surface, already condensed to its utmost, will not change with the core; it cannot reduce its area, but it adapts itself to the shrinking interior by taking a shape which occupies less bulk. So the earth is to become a tetrahedron, a sort of pyramid, the shape which gives the smallest bulk for its surface. Let us think about it all.

Tuesday, August 16, 2011

Sunday, August 14, 2011

"Beware of polysemy"

...according to Pillai 1983:202 [a Malayalam-English dictionary], the Malayalam word kʌkʂʌ means not only ‘girth rope of an elephant’, but also ‘waistband of a woman, a courtyard, a surrounding wall, inner room or harem of a palace, objection or reply in an argument, the orbit of a planet, a boil in the armpit, armpit, flank, river side, forest, dry grass, bull or buffalo, a hiding place, harem, scale of a balance, sin, a tortoise, a treasure of Kubera, a narrow undercloth covering the privities [sic], a dog, a harem supervisor, a poet, a painter, a debauchee’!
From Linguistic Field Methods by Bert Vaux and Justin Cooper. English has some striking polysemous words of its own, such as the answers to these riddles (which can be found in the linked posts):
What do loads, accumulations, obligations, and (idiomatic) kicks have in common with management, custody, people in care, sets of instructions, expenditures, liabilities, prices, loan records, and allegations?
What do support poles, staff positions, battery terminals, army encampments, blog articles, earring stems, trading stations, and snail mail have in common with billboard advertising, accounts recording, making bail, and assigning diplomats?

Wednesday, August 10, 2011

Teeny trilobite

I found this while cleaning out the drawers in my closet (it was probably a gift from my grandparents). The fossil is just under an inch long. It's probably Elrathia kingi, a Cambrian-era fossil which is common in Utah.

Monday, August 8, 2011

Springtime on Mars

From NASA's Astronomy Picture of the Day, which provides this explanation:
What is causing these dark streaks on Mars? A leading hypothesis is flowing -- but quickly evaporating -- water. The streaks, visible in dark brown near the image center, appear in the Martian spring and summer but fade in the winter months, only to reappear again the next summer. These are not the first markings on Mars that have been interpreted as showing the effects of running water, but they are the first to add the clue of a seasonal dependence... The streaks bolster evidence that water exists just below the Martian surface in several locations, and therefore fuels speculation that Mars might harbor some sort of water-dependent life. Future observations with robotic spacecraft orbiting Mars, such as MRO, Mars Express, and Mars Odyssey will continue to monitor the situation and possibly confirm -- or refute -- the exciting flowing water hypothesis.
Millions of years ago, Mars may have had an ocean, which might have supported microbial life. Perhaps Martian microbes still thrive today in regions where floods occur, rising from dessicated dormancy when spring rolls around.