The European Southern Observatory, utilising its Harps instrument in concert with data from the European Space Agency’s CoRoT spacecraft, has discovered an extrasolar planet about the size of Jupiter in the constellation Serpens. Designated Corot-9b, the planet is about 1,500 light years away from our solar system. “This is a normal, temperate exoplanet just like dozens we already know, but this is the first whose properties we can study in depth,” says Claire Moutou, one of the team of 60 astronomers that made the discovery. “It is bound to become a Rosetta stone in exoplanet research.” The research appeared in Nature.
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27 March 2010
Elephantine Speed
The physics behind the astounding charge of a bull elephant had remained somewhat of a mystery till recently.
motion
Can elephants run? A strange question for anyone who has ever witnessed the charge of a bull elephant, but pertinent given the elephant’s size. Most animals transit easily from a walk to a bouncy run, often with all four limbs off the ground, but nature has obviously not designed a four-tonne elephant to bounce or float in air. So how do elephants manage to move fast with such efficiency?
They seem to have an exceptionally stable and efficient way of moving fast. After all, a human runner exerts force thrice his body weight when running, while an elephant manages to move by exerting a maximum force of just 1.4 times its body weight. Moreover, the elephant’s centre of mass shifts by less than a centimetre while moving fast, a feat no human runner can match. Put this together and an elephant’s cost of transport is one-third of a human’s, weight for weight.To understand this pachydermal ability, Belgian scientists studied Asian elephants in Thailand. It was no easy feat: it required an 8 metre long force platform with reinforced concrete foundations. Spurred on by a mahout to their equivalent of a run, the forces generated by 34 different elephant, ranging from a 870 kg baby to a 4 tonne adult, were measured.
Most animals while running convert the energy stored in muscles into bouncing kinetic energy by bobbing up and down, but while walking they convert stored energy into swaying energy by a gentle pendulum-like motion. Elephants, the study showed, tended to fall somewhere in between. In the first half of their stride they bobbed from side to side to maintain a constant level, while in the second half of the stride they bobbed up and down like a runner.
“They don’t really run in the classical sense,” says Heglund, one of the authors of the study. “They can’t quite kick it into second gear, so they’re stuck halfway in between.” So an elephant manages a half-run, half-walk, keeping at least two legs on the ground even at full speed. In short, the answer is the front legs walk while the rear ones trot.
Science Buzz
27 Mar 2010 - 2 Apr 2010
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It was previously thought that sex chromosomes in birds control whether a testis or ovary forms, with sexual traits then being determined by hormones. A study by The Roslin Institute at the University of Edinburgh, however, identified differences between sex cells that control the development of sexual traits. They call the phenomenon cell autonomous sex identity. The study involving chickens with white (male) plumage on one side and brown (female) plumage on the other. Dr Michael Clinton, who led the study, said: “We now believe major factors determining sexual development are built into male and female cells”.
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A new study reports that the male pipefish can be a nurturing father as it tends its young before giving birth, but later it may not if it is not very fond of the mother. These findings, from Texas A&M University researchers, were published in Nature. The researchers studied consecutive broods in male Gulf pipefish to find out why some offspring survive while others do not. Their results reveal that males who were especially fond of the females they had mated with were more likely to show a nurturing attitude toward their offspring. In almost every case, those that were not very fond of the mother were less nurturing toward their young.
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