* Wild Goose Chase * Quantum Peek-a-boo * Cannibal Sea Urchins * Losing Nemo * Observations of the Quantum Man *

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Wild Goose Chase

himalayan_geese.jpg Bar-headed goose fitted with satellite back-pack.  John Takekawa
When mountaineers climbing in the Himalayas first noticed bar-headed geese flying overhead, scientists began to wonder how these birds were able soar so high in such thin air.  The geese migrate across the mountains from India to Central Asia at heights of 6,000 metres, in just seven or eight hours.  The conventional wisdom was that they made use of the tail winds and updrafts that prevailed in the afternoon.  This seemed to explain the ease with which they made the journey, but it didn't explain how they dealt with the lack of oxygen.  But a new study by Dr. Graham Scott, formerly at the Department of Zoology at the University of British Columbia, has come up with a possible explanation.  Small satellite back-packs attached to the geese revealed they fly at night and early morning when the air is much cooler.   Cooler air is more dense, provides greater lift and has a higher oxygen content.  Dr. Scott is currently a post-doctoral research fellow in the School of Biology at St. Andrews University in Scotland.     

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Quantum Peek-a-boo

trajectories.gifReconstructed photon trajectories, courtesy Science.
The Double-slit experiment is considered one of the most beautiful experiments in physics, and it's also one of the strangest.  It exhibits the strange quantum phenomenon of the dual particle/wave nature of small objects.  It also illustrates the quantum uncertainty by which the behaviour of these objects changes, depending on whether they're observed or not.  Dr Krister Shalm, a post-doctoral fellow at the Institute for Quantum Computing at the University of Waterloo, and his colleagues, have performed a new variation on this two-hundred-year-old experiment.  They've been able to take sneak peeks at the experiment, without disturbing its strange quantum state, to get a better picture of what nature is doing when we aren't looking.   

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Cannibal Sea Urchins

cannibalized_urchin.jpg Cannibalized urchin, courtesy C. Richardson
It is known that certain fish raised for human consumption will resort to cannibalism when under the stressful conditions of overcrowding and lack of food in tanks used in aquaculture.  A new study by Cristina Richardson, a former graduate student in the Department of Biology at the University of Alabama, has found that sea urchins will do the same in similar conditions.  In young sea urchins, cannibalization is driven by their energy needs when food is scarce; for the adults, it is more a matter of maintaining territory.  Sea urchins are not known to cannibalize in the wild.   As aquaculture becomes more important to both the survival of the species and the growth of the commercial sea urchin industry, identifying such a threat is critical.  Sea urchins are prized for their edible gonads, particularly in countries like China and Japan.     

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  • Paper in Journal of Experimental Marine Biology and Ecology
  • Story from Discovery News
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Losing Nemo

clownfish.jpg Clownfish, copyright Nick Hopgood
Since the Industrial Revolution, over half of the CO2 emitted by the burning of fossil fuels has been absorbed by the oceans.  This has resulted in lower pH levels, which means the oceans are becoming more acidic.  Based on today's trends, scientists feel ocean acidification will only increase.  This has already had an adverse effect on the sense of smell in some fish.  But Dr. Steve Simpson, a marine biologist from the University of Bristol in England, has recently found in studies involving the tropical Clownfish, hearing is also damaged.  Both senses are key to the Clownfish's ability to forage, mate and navigate their way through the coral reefs where they live.  In an experiment where projected CO2 levels for 2050 and 2100 were simulated, Clownfish did not respond to recordings of underwater reef noises.  It is not known whether Clownfish, and many other similar species, will be able to adapt to increasing ocean acidification over time.

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Observations of the Quantum Man

quantum_man.jpg
Dr. Richard Feynman might well be the first Nobel Prize-winning physicist you would choose to have a beer with.  He was charismatic, funny, quick-witted and an inveterate prankster.  Indeed, he was his own best mythologizer and his memoirs are full of colourful stories and amusing anecdotes.  All this, perhaps, tends to obscure the importance of the science Feynman did.  But Canadian physicist Dr. Lawrence Krauss, Foundation Professor and Director of the Origins Project at Arizona State University, hopes to remedy that.  In Quantum Man: Richard Feynman's Life in Science, Dr. Krauss traces Feynman's colourful life through the important science he did, which went well beyond the Quantum Electrodynamics work for which he won his Nobel Prize.    

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Theme music bed copyright Raphaël Gluckstein, Creative Commons License by-nc-nd-2.0