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scrubjThe Economist: HOARDING provisions for future use is not unique to humans. Birds, squirrels and monkeys do it. But the ability to think not just about tomorrow, but to realise how tomorrow's feelings might differ from today's, was thought to be the preserve of people (Bischof-Köhler hypothesis). This week researchers demonstrated that Western scrub-jays, a type of crow, can do it too. <>

To test whether this is so, Nicola Clayton et al. sought to tease apart scrub-jays' momentary desires from their planning for future needs. They let the birds eat as much of one food as they wanted, exploiting a condition called specific satiety—once the birds are full of one food, they show strong preference for something different. They then offered the birds that same food or a second one to store for later.

Initially the scrub-jays behaved as predicted, choosing to stow away the second food, which they had not just eaten. But minutes before allowing the birds to recover their stash, the researchers fed the birds to satiety with that second food—the one they had already stored. The birds changed their caching preferences on the very next trial. Even though they had just had their fill of the first food, they still cached it, presumably because they thought it would be their preferred choice later. The results are published in this week's Current Biology

The finding matters because the birds seem to plan ahead for what they will want later, even though their choice conflicts with what they want now. [Source]

Nature: Vincent van Gogh is known for his chaotic paintings and similarly tumultuous state of mind. Now a mathematical analysis of his works reveals that the stormy patterns in many of his paintings [The Starry Night (1889), Road with Cypress and Star (1890), and Wheat Field with Crows (1890)] are uncannily like real turbulence, as seen in swirling water or the air from a jet engine.
"We think that van Gogh had a unique ability to depict turbulence in periods of prolonged psychotic agitation," says physicist Jose Luis Aragon. Click here (mirror) to read the whole story.

pigeonNew Scientist: CONFUSED by logarithms? If so, you'll be surprised to hear they come naturally to pigeons and possibly, subconsciously, to you.

There are asymmetries in the way animals perceive numbers and time, and a recent experiment showed that pigeons underestimate the midpoint between two time intervals.

In the experiment, pigeons were trained to tap one lever when a light flash was "short", perhaps 1 second long, and another lever when the flash was "long", say 16 seconds. When the birds then saw flashes of intermediate length, you would expect them to distinguish long from short around the mid-point of 8 or 9 seconds. But instead they switched at 4 seconds.

Pigeons might perceive time on a logarithmic scale on which higher values are increasingly compressed together. Alternatively, they might perceive time linearly but are confused by longer intervals. If pigeons use a log scale, they will correctly classify 9 and 10-second flashes more often than 7 and 8-second flashes, while if they use a linear model their accuracy should be similar. William Roberts from the University of Western Ontario in London, Canada, has now shown that six pigeons, tapping levers for 20 days, conformed neatly to the logarithmic model (Behavioural Processes, vol 72, p 207).

The results may apply to humans, because brains have to prioritise the small numbers most relevant in life. It might be an evolutionary strategy to discriminate numbers like this, says Roberts. [Source]

How life on Earth got going is still mysterious, but not for want of ideas

dreamNature: Although horror films frequently depict victims disappearing in quicksand, the truth is much tamer. People cannot fully sink into this type of soil, and laboratory simulations now bear out this little-known fact.

Click here to read the whole story.

poincaredodecahedralIOP: People have long been fascinated by the size and shape of the universe. The current consensus among astronomers is that the universe is flat - which means that parallel lines never meet - and that it is infinite in size. Some of the strongest evidence for this view comes from measurements of the cosmic background radiation - a fuzz of microwaves known as the echo of the big bang - made by NASA's WMAP satellite. However, when the results from WMAP are compared with theory at large angles, there is a discrepancy that suggests that the universe might not be flat or infinite after all. Indeed, as Jean-Pierre Luminet of the Observatory of Paris explains, the data might be better explained by a universe that is shaped a bit like a football soccer ball - a Poincaré dodecahedron to be precise. Moreover, the universe resembles a video game in that if you disappear out through one of the "panels" that make up the football, you immediately re-appear through another panel on the opposite side.

Arnold Kling asks (see here) who is the most influential person in world history, and suggests names like Locke, Smith, and Marx.

In my opinion this general question is biased towards the knuckleheads like Marx who were fabulously influential and wrong. This is because influential mistakes create something neither anticipated nor inevitable, while right ideas are somewhat inevitable. Thus good ideas are not so dependent on "great men" because there are lots of smart people and they eventually find the truth (witness the simultaneous discovery of things like evolution by Wallace and Darwin, calculus by Newton and Leibniz, or marginal analysis in economics by Menger, Jevons, and Walras). Bad ideas, in contrast, are infinite in number, and require a special magnetism and impenetrable self-assurance by their champions in order to become influential. Freud is a perfect example, a charlatan who befuddled two generations via his implacable self-esteem. Marx was similar, and Ayn Rand was cut from the same cloth but fortunately her radical ideas against empiricism never had as deleteriously wide an impact as Marx or Freud.

So for an individual to have great impact, it is probably in some wrong-headed idea about something not obviously falsifiable.

Have you ever thought about the power of a paper clip? If you could convert the mass of a paper clip entirely to energy, how big a punch would it pack? In this quiz, discover the answer and explore other examples of what scientists call mass-energy equivalence.

E = mc2 Explained: Hear how 10 top physicists—two Nobel Prize winners among them—describe the equation in a few minutes or less. Click here to listen directly to Einstein.

Nature: Habit memory is acquired subconsciously and slowly, by trial-and-error. It is more easily studied in animals than in humans, because of our strong tendency to acquire information as conscious (declarative) knowledge. Yet our capacity for unconscious learning is a vital aspect of the human condition, facilitating many routine tasks. Now it can be confirmed that humans do have a robust capacity for habit learning. Two patients with large medial temporal lobe lesions and profound amnesia were asked to acquire a task that is ordinarily learned by conscious memory. They learned gradually, in the way that monkeys learn the same task, and without being aware of what was being learned. The knowledge was rigidly organized, and performance collapsed when the task format was altered. Click here to read the story.

nailstoragePhysicsWeb: Secure optical data storage could soon literally be at your fingertips thanks to work being carried out in Japan. Yoshio Hayasaki of Tokushima University and colleagues have discovered that data can be written into a human fingernail by irradiating it with femtosecond laser pulses. Capacities are said to be up to 5 mega bits [655 360 bytes] and the stored data lasts for 6 months -- the length of time it takes a fingernail to be completely replaced (Optics Express 13 4560). Continue Reading

via jupe