The Law of Urination * Mighty Mouse Immune to Scorpion's Pain * Money Grows On Trees * Clearing Space with Electricity * Boreal Forest's Future on Fire * A 200-Day Non-stop Flight

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Physical laws, like the Laws of Thermodynamics and Newton's Laws of Motion, recognize mathematical patterns in nature. Today, we look at the #1 new physics law, which a scientist has defined as the Law of Urination. Apparently there's a method to our micturation. Plus, we'll hear about a fearsome mouse that eats venomous scorpions; we'll find out how gold grows on trees; we'll look at a clever scheme to take out the garbage in geostationary orbit; we'll look at the future of fire in the boreal forest, and we'll find out about the non-stop, six-month flight of the swift

 

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The Law of Urination

Dr. David Hu, Professor of Mechanical Engineering and Biology at the Georgia Institute of Technology, was interested in the physics of urination, which he thinks might be important for understanding some urological disorders.  While studying urination in more than two dozen species of mammals, ranging in size from mice to elephants, he discovered an interesting and surprising pattern he's calling, "The Law of Urination."  Urination takes, on average, about twenty seconds in animals ranging from 1 kilo to several tonnes, whether their bladders void 100ml or 155 litres of liquid. This requires different mechanisms in different sized animals, depending on whether excretion just relies on bladder pressure, or gravity.
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Mighty Mouse Immune to Scorpion's Pain

The venom of the bark scorpion is the most toxic of any scorpion in North America.  The scorpion mostly eats insects, like crickets and roaches, but will sting - which usually kills - anything that attacks, including the carnivorous grasshopper mouse that lives in the same desert regions of the south-west United States.  But the grasshopper mouse is resistant to the pain of the bark scorpion's sting.  New research by Dr. Ashlee Rowe, an Assistant Professor in the Neuroscience Program and Zoology Department at Michigan State University, has found that the mouse has evolved a specific defence against the toxin.  Dr. Rowe, who conducted the research while at The University of Texas at Austin, found the bark scorpion toxin acts as a analgesic by binding to an amino acid in a particular sodium channel in the pain neurons of the mouse.  This blocks the neuron from sending a pain signal to the brain.

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Money Grows On Trees


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Eucalyptus Tree, courtesy Melvyn Lintern

Mining for gold in Australia might have just become as easy as finding a nearby eucalyptus tree. Dr. Melvyn Lintern, a geochemist at the Commonwealth Science and Industrial Research Organization in Perth, Australia, has found gold particles in the leaves, twigs and bark of the common eucalyptus tree, also known as the gum tree.  The 30-metre-deep roots of the eucalyptus act as a hydraulic pump that moves water containing the particles, from nearby underground deposits, into the tree.  The highest concentration of gold particles were found in the leaves.  It is hoped this find may result in more efficient exploration for gold. 


Related Links

  • Paper in Nature Communications
  • CSRIO news blog
  • CSRIO release
  • National Geographic news
  • Smithsonian Magazine's Surprising Science blog

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Clearing Space with Electricity


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Courtesy Dr. Schaub
Nearly 60 years into the Space Age, we're starting fill up valuable orbital real-estate with space junk. At geosynchronous orbit, where communications satellites are generally stationed, there are many more dead satellites than functional ones. And the dead ones, apart from taking up space, can drift and move around and threaten the functioning orbiters.  Dr. Hanspeter Schaub, from the Aerospace Engineering Sciences Department at the University of Colorado, Boulder, has developed plans for a "space tug" that would capture drifting objects without having to touch them, using an electrostatic tether. The tug would then drag the space junk to a safe disposal orbit.

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Boreal Forest's Future on Fire

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Warming conditions in the North are already increasing the intensity and frequency of forest fires. The boreal forest, however, is adapted to fire, and, indeed, many of its tree species require fire in order to reproduce.  Trees like jack-pine and black spruce produce sealed cones that are opened by the heat of forest fires, allowing the forest to regenerate.  Dr. Jill Johnstone, Professor of Biology at the University of Saskatchewan, and her colleagues, have been studying what happens if fire becomes too frequent in the boreal forest.  What they've found suggests that that once fires start coming every 30 years - about three times more frequent than normal - these fire-adapted trees can't regenerate fast enough.

Related Links

  • University of Saskatchewan release 
  • Paper to appear in November, 2014 edition of the journal Bioscience

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A 200-Day Non-stop Flight

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Alpine Swift, courtesy Birdwatching Barcelona
The Alpine Swift migrates from central Europe to sub-Saharan Africa, from September to April. The journey takes about two weeks each way.  But as impressive as this migration is, in terms of distance, the swift is capable of equally astounding non-stop flight.  New research by Dr. Felix Liechti, the Head of The Bird Migration Department at the Swiss Ornithological Institute, attached tiny data loggers to six swifts and found that they can stay airborne for 200 days.  It is thought they sleep by shutting down half of their brain, as dolphins are known to do in the water. This enables the swift to perform a high altitude gliding function, but rest at the same time.  They eat by capturing insects on the fly.  Such long non-stop flights may help avoid predation, as well as reduce the chances of being bitten by parasitic insects like mosquitoes.

Related Links

  • Paper in Nature Communications
  • Not Exactly Rocket Science blog
  • Smithsonian Magazine's Surprising Science blog

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