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Saturday January 29, 2011

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  • The Earliest Galaxy
  • The Red Fox's Magnetic Attraction
  • Man Bites Dog
  • Spring-loaded Seeds
  • Craving Constants

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The Earliest Galaxy


earliest_galaxy.jpg NASA, ESA, Garth Illingworth (UC Santa Cruz), Rychard Bouwens (UC Santa Cruz and Leiden University) and the HUDF09 Team.
The Hubble telescope's latest upgrade has led to the detection of the earliest and most distant galaxy yet seen.  It existed just 480 million years after the Big Bang, and its light has been travelling towards us for 13.2 billion years.  Dr. Rychard Bouwens, an astronomer at the University of Leiden in the Netherlands, led the team that was able to tease out the faint light from this galaxy from an image taken by Hubble over an exposure of 87 hours.  Only one galaxy this early was detected in the image, which suggests the epoch of galaxy formation in the early universe might have started a little more slowly than had been thought. 

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The Red Fox's Magnetic Attraction

Mousing_fox.jpg Mousing fox, courtesy Jaroslav Vogeltanz
We know the fox to be sly and cunning, but new research by Dr. Sabine Begall, the Associate Head of the Department of Zoology at the University of Duisberg-Essen in Germany, has found another remarkable trait.  Foxes have the ability to find prey in either tall grass or under cover of snow, using the Earth's magnetic field.  For this reason, the fox has a preference for facing magnetic north, within ten degrees, when hunting.   The research showed a much higher success rate when the fox aligned itself in this way than in any other direction.  The research suggests that the fox sees a shadow on its retina that is darkest toward magnetic north.  Like a normal shadow, this 'image' appears to be a constant distance ahead of the fox.  When the shadow lines up with where the fox perceives the sound of a mouse, for example, it launches itself into the air, coming straight down on its prey. 

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Man Bites Dog

Inca_Hairless_Dog.jpg An Inca Hairless Dog, copyright cc-by-3.0, Thom Quine

A discovery of a bone in a sample of ancient feces suggests that, for early North Americans, Old Blue was, on occasion, the Blue Plate Special.  Samuel Belknap, a graduate student in the Department of Anthropology and the Climate Change Institute at the University of Maine, was studying ancient human feces to get insight into the diet of the people who deposited it.  At first he didn't recognize the small fragment of bone he found in one sample; but working with colleagues, he identified it as part of a dog's skull.  DNA analysis later proved that this dog's ancestors were probably brought over from Asia when humans migrated into North America.  Just why ancient North Americans ate this particular dog is not known, but dog was often on the menu in later Aboriginal societies.

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  • News from the University of Maine
  • Discovery News
  • National Geographic News

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Spring-loaded Seeds

clockface_seed.jpg Time-lapse photo of awn coiling in the seed of Erodium cicutarium, courtesy Jacques Dumais
The Filaree plant (Erodium cicutarium), also known as Stork's Bill, is a small flowering plant in the geranium family. It is found in dry areas around the Mediterranean and in the southern United States - and possesses two amazing qualities.  First, the mother plant can fling its seed up to half-a-metre away. This happens after the seed's tail-like structure, called an awn, has dried, then coiled, then finally released in an explosive display of kinetic energy. Second, once on the ground, the seed can drill itself into the soil by repeatedly curling and unwinding the awn in response to levels of humidity.  Canadian scientist Dr. Jacques Dumais, an Associate Professor of Organismic and Evolutionary Biology at Harvard University, says the plant's seed dispersal and self-drilling mechanisms are designed to increase chances of germination.

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Craving Constants
Albert_Einstein.jpgDr Einstein might have been surprised...
The laws of physics that explain why atoms hold together, why stars burn, and why electricity flows in a wire, all depend on a range of special numbers - the constants of nature.  These include things like the speed of light, the charge on an electron and the gravitational constant to name a few.  The fact that these numbers don't change, no matter where or when you are in the universe, is one of the things that allows us to understand the universe and predict its future evolution.  However, a small group of scientists, bolstered by a few tantalizing fragments of evidence, are considering a radical idea: what if the constants of nature aren't so constant?  Quirks producer Jim Lebans takes a look at this cosmological conundrum, by talking with these scientists:

Dr. John Webb, an astrophysicist from the University of New South Wales in Australia, has looked into this idea by probing the chemistry of the distant universe - seeing how quasar light shines on distant gas and dust.  He's found evidence that an important constant, the Fine Structure Constant, may be different in different parts of our universe. 

The implications of changing constants are huge for physics, and would mean much of physics would have to be re-thought, according to Dr. João Magueijo, a cosmologist from Imperial College, London.   Dr. Magueijo, however, thinks that if constants vary, it might also open physics to new ideas, including his own theory that a faster speed of light early in the Big Bang might explain the rapid expansion of the universe. 

Dr. John Barrow, a cosmologist and mathematician from Cambridge University, suggests that constants might change, depending on how far we travel through space.  This idea comes from the notion that the Big Bang created multi-verses, or "bubble universes," each with its own physical properties.  

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


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