research

Fruit Flies, Fighter Jets Use Similar Evasive Tactics When Attacked

When startled by predators, tiny fruit flies respond like fighter jets – employing screaming-fast banked turns to evade attacks. Researchers at the University of Washington used an array of high-speed video cameras operating at 7,500 frames a second to capture the wing and body motion of flies after they encountered a looming image of an approaching predator (abstract). ‘We discovered that fruit flies alter course in less than one one-hundredth of a second, 50 times faster than we blink our eyes, and which is faster than we ever imagined.’ In the midst of a banked turn, the flies can roll on their sides 90 degrees or more, almost flying upside down at times, said Florian Muijres, a UW postdoctoral researcher and lead author of the paper. ‘These flies normally flap their wings 200 times a second and, in almost a single wing beat, the animal can reorient its body to generate a force away from the threatening stimulus and then continues to accelerate,’ he said.

First there was the anternet, and now this? It almost sounds like humans a giant insects…

The anternet

Stanford researchers discover the ‘anternet’

Transmission Control Protocol, or TCP, is an algorithm that manages data congestion on the Internet, and as such was integral in allowing the early web to scale up from a few dozen nodes to the billions in use today. Here’s how it works: As a source, A, transfers a file to a destination, B, the file is broken into numbered packets. When B receives each packet, it sends an acknowledgment, or an ack, to A, that the packet arrived.

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. Gordon has found that the rate at which harvester ants – which forage for seeds as individuals – leave the nest to search for food corresponds to food availability.

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.

Prabhakar wrote an ant algorithm to predict foraging behavior depending on the amount of food – i.e., bandwidth – available. Gordon’s experiments manipulate the rate of forager return. Working with Stanford student Katie Dektar, they found that the TCP-influenced algorithm almost exactly matched the ant behavior found in Gordon’s experiments.

Assassin’s Creed might be for real

Wikipedia describes the Assassin’s Creed game premise like so:

The Assassin’s Creed games primarily revolves around the rivalry between two ancient secret societies: the Assassins and the Knights Templar, and their indirect relation to an ancient species pre-dating humanity, whose society, along with much of Earth’s biosphere, was destroyed by a massive solar storm. The games’ real-world chronological setting is the year 2012, and feature Desmond Miles, a bartender who is a descendant of several lines of prominent Assassins; though raised as an Assassin, he fled his nomadic family to seek out a more common lifestyle. He is initially kidnapped by the megacorporation Abstergo Industries, the modern-day face of the Knights Templar, who are aware of Desmond’s lineage. Desmond is forced to use the “Animus”, a device that allows him to experience his ancestral memories.

Initially, when I started playing Assassin’s Creed, I thought that this whole ancestral memory exploration idea was very cool. It gave the game an easy opportunity to travel back in time, as well as it explained how the main character could die and resurrect many times during the course of the game.

Well, apparently, this is not all fiction – there is a scientific basis for the idea. Mysterious Universe covers a few bits of research, including this:

Prof Marcus Pembrey, from University College London, said the findings were “highly relevant to phobias, anxiety and post-traumatic stress disorders” and provided “compelling evidence” that a form of memory could be passed between generations.

He commented: “It is high time public health researchers took human transgenerational responses seriously.”

Not exactly an exploration of ancestral memories yet, but a step in that direction.

Can toroid planets exist?

Coldest Spot On Planet Earth

Slashdot lets us know that we finally know where’s the most freezing place on Earth:

What is the coldest place on Earth? It is a high ridge in Antarctica on the East Antarctic Plateau where temperatures in several hollows can dip below minus 133.6 degrees Fahrenheit (minus 92 degrees Celsius) on a clear winter night. Scientists made the discovery while analyzing the most detailed global surface temperature maps to date, developed with data from remote sensing satellites including the new Landsat 8, a joint project of NASA and the U.S. Geological Survey (USGS). Ted Scambos, lead scientist at the National Snow and Ice Data Center in Boulder, Colo., joined a team of researchers reporting the findings Monday at the American Geophysical Union meeting in San Francisco. Researchers analyzed 32 years’ worth of data from several satellite instruments. They found temperatures plummeted to record lows dozens of times in clusters of pockets near a high ridge between Dome Argus and Dome Fuji, two summits on the ice sheet known as the East Antarctic Plateau. The new record of minus 93.2 C was set Aug. 10, 2010.

The linked article from NASA has a nice visualization in the form of the YouTube video:

[youtube=http://www.youtube.com/watch?v=Hp6wMUVb23c]

One thing that is not so obvious about this research is the problem with tools – most thermometers that we are using elsewhere will simply stop working at these temperatures.

And just in case you were wondering how cold is it in space, here is a very nice explanation:

[youtube=http://www.youtube.com/watch?v=6QE3oHoTgUQ]