Recent articles

Thursday, December 9, 2010

Highest ever energy bursts detected from the usually sedate Crab nebula.

The Large Area Telescope on board the Fermi Gamma-ray Space Telescope recently measured two gamma-ray flares coming from the Crab Nebula (M1, NGC 1952); which at 10^15 eV, scientists believe to be the highest energy ever associated with a discrete astronomical source.

The brevity of the flares implies that the gamma rays are emitted via synchrotron radiation from PeV electrons in a region smaller than 1.4 10^-2 pc.

The Crab Nebula has been used as a reference source to calibrate telescopes in several wavebands, in particular at high energies because of its bright and historically steady emission.

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NASA's Spitzer reveals a carbon-based planet

Astronomers have discovered that a huge, searing-hot planet orbiting another star is loaded with an unusual amount of carbon. The planet, a gas giant named WASP-12b, is the first carbon-rich world ever observed. The discovery was made using NASA's Spitzer Space Telescope, along with previously published ground-based observations.
This plot indicates the presence of molecules in the planet WASP-12b
"A carbon-dominated terrestrial world could have lots of pure carbon rocks, like diamond or graphite, as well as carbon compounds like tar," said Joseph Harrington of the University of Central Florida, in Orlando, who is the principal investigator of the research."

Tuesday, November 9, 2010

Thirty years before the publication of Origin of Species, Patrick Matthew (1790-1874) publishes a theory of natural selection that not only predates Darwin's, but is now considered to be more accurate.

In a little-known 1831 book, Naval Timber and Arboriculture, Matthew concludes that catastrophic events such as mass extinctions are the prime factor in the process of evolution; an idea that Darwin rejects in his works in favor of "gradual changes in the characteristics of surviving organisms."

New York University Geologist Michael Rampino, in an essay recently published in the journal Historical Biology writes that the now commonly held view of evolution is that it is driven by major ecological changes that occur both episodically and rapidly, casting doubt on Darwin’s theory.

Rampino notes that Darwin and his colleague Alfred Russel Wallace acknowledged that Matthew was the first to put forth the theory of natural selection; but despite this Matthew has gone uncredited and unsung for what is possibly the greatest scientific leap in human history.

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