* Re-setting the Periodic Table * Mammoth Moms * Finding a Fourth Planet * Whistling Caterpillars * Voyager and the Third Age of Discovery *

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Re-setting the Periodic Table

Whether or not you remember all of its more than one hundred elements, anyone who has ever studied chemistry is familiar with the Periodic Table.  Dr. Michael Wieser, an Associate Professor in the Department of Physics and Astronomy at the University of Calgary, says the Table is the face of chemistry.  But now it needs to be re-set. He is part of an international team of scientists working on giving the Periodic Table of Elements a facelift; not because of the addition of new elements, as in the past; but this time, the atomic weights of ten elements are being restated with greater accuracy.  Some, once thought to be constant, are not.  The ten chosen show the greatest variability in atomic weight.  They are hydrogen, lithium, boron, carbon, nitrogen, oxygen, silicon, sulphur, chlorine and thallium.

Related Links

• Paper in Pure and Applied Chemistry
• The Commission on Isotopic Abundances and Atomic Weights
• The International Year of Chemistry
• Updated Periodic Table
• Dr. Michael Wieser
• News from the University of Calgary
• CBC News story
  

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Mammoth Moms

Courtesy University of Western Ontario

The woolly mammoth thrived in many places on Earth until about ten thousand years ago, near the end of the Pleistocene Epoch.  Its extinction is believed to be due to climate change or the result of hunting by humans - or a combination of the two. But now new research by Jessica Metcalfe, a PhD candidate in the Earth and Environmental Sciences Department at the University of Western Ontario, suggests there may have been another contributing factor, at least for woolly mammoths living north of the Arctic Circle.  By studying the chemical composition of infant mammoth teeth, she discovered that they didn't begin eating solid foods until at least the age of two.  This prolonged nursing period may have been a survival adaptation due to the harsh environment, including sparse vegetation and prolonged hours of darkness.  But it may have also contributed to their demise, because the delayed onset of weaning resulted in a greater energy requirement for mothers to produce milk, and fewer new births.

Related Links

• Paper in the journal Palaeo
• News from University of Western Ontario (with video)
• CBC News story 
  

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Finding a Fourth Planet

Courtesy NRC-HIA, C. Marois & Keck Observatory

The search for extra-solar planets is one of the hottest areas of astronomy today. But even so, the work of a Canadian-led team in not just detecting, but directly imaging planets around a nearby star, is remarkable.  Two years ago, they found three giant planets orbiting the star HR8799, about 130 light years away.  They've now announced that they've seen a fourth planet orbiting even nearer the star.  These planets are all young, hot gas giants, which makes them quite bright, which is what allows them to be seen at all in the glare of the light from their star.  But according to Dr. Bruce Macintosh, a Canadian physicist at Lawrence Livermore National Laboratory in California, the addition of a fourth planet to this system adds to a puzzle.  No current theory can explain how it came to be.

Related Links

• Paper in Nature
• News from the National Research Council
• News from UCLA
• CBC News Story (in side bar)
  
• Interview about group's previous discovery on Quirks

 
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Whistling Caterpillars

Walnut Sphinx Caterpillar, Courtesy Jayne Yack

The walnut sphinx caterpillar, found throughout Canada, feeds on walnut and oak.  In its final stage of development, it is about 5-6 cm in length.  This caterpillar is known to be a master of camouflage, but according to Dr. Jayne Yack, an Associate Professor in the Department of Biology at the Carlton University in Ottawa, the walnut sphinx caterpillar has a more impressive and surprising quality - it has the ability to whistle.  The caterpillar can blow air out of two holes found in the abdominal spiracles and make a squeaking sound that fends off attacking birds.  Warblers used in one experiment were so afraid of the 4-second-long sound, they did not return to resume their attack.  It may be that the walnut sphinx caterpillar is mimicking the alarm call of another predatory bird.

Related Links

• Paper in the Journal of Experimental Biology
• Inside JEB story 
• News from Carleton University
• Dr. Jayne Yack

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Voyager Launches the Third Age of Discovery

In 1977, NASA launched twin probes on the most ambitious planetary mission ever attempted.  Voyager 1 and 2 would visit Jupiter and Saturn, slingshot around them, and head for deep space, encountering Neptune and Uranus along the way.  Their remarkably successful mission was really our first meaningful exploration of the outer Solar System.  In his new book, Voyager: Seeking Newer Worlds in the Third Great Age of Discovery, Dr. Stephen Pyne from Arizona State University explores the similarities between Voyager's exploration, and the great ages of exploration in humanity's past.  Dr. Pyne makes the case that in terms of cultural and scientific importance, Voyager opened a new age of discovery by robotic proxy for humanity, as significant as the previous ages of discovery in the Renaissance and the Enlightenment.  

Related Links

• Voyager: Seeing Newer Worlds in the Third Great Age of Discovery
  
• Dr. Stephen Pyne
• NASA's Voyager Page
  

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