Thursday, October 30, 2014
Sunday, October 26, 2014
'Scientists have reconstructed the genome of a man who lived 45,000 years ago, by far the oldest genetic record ever obtained from modern humans. The research, published on Wednesday in the journal Nature, provided new clues to the expansion of modern humans from Africa about 60,000 years ago, when they moved into Europe and Asia.
And the genome, extracted from a fossil thighbone found in Siberia, added strong support to a provocative hypothesis: Early humans interbred with Neanderthals.
Monday, October 13, 2014
'A string of a dozen volcanoes, at least several of them active, has been found beneath the frigid seas near Antarctica, the first such discovery in that region.
Some of the peaks tower nearly 10,000 feet (3,000 meters) above the ocean floor — nearly tall enough to break the water's surface.
"That's a big volcano. That's a very big volcano. If that was on land it would be quite remarkable," said Philip Leat, a vulcanologist with the British Antarctic Survey who led a seafloor mapping expedition'
Technologies like this allow us to imagine a new form of quarantine. Rather than relying on primitive instruments, indiscriminate profiling or questionnaires, we should consider running a pilot program to test asymptomatic travelers using sensitive P.C.R.-based techniques. Obviously, such technologies are expensive, but the cost is not prohibitive. A typical P.C.R. reaction, including labor, costs between $60 and $200 (we have already spent 100 times more disposing of the contaminated sheets from the home Mr. Duncan stayed in). Since the test takes about a third of the time of a trans-Atlantic flight, the flight would become the quarantine.
Huge logistical questions would need to be solved. Where would such a screening test be administered — before departure from West Africa, or upon landing? Could we imagine a walking quarantine in which travelers were granted provisional entry, but recalled if they tested positive? What infection precautions would need to be in place for such testing? What forms of consent would be required? Who would bear the costs? Who exactly would be tested?'
'Duke University researchers have made fluorescent molecules emit photons of light 1,000 times faster than with previous designs — a speed record, and a step toward realizing superfast light-emitting diodes (LEDs) for nanophotonic devices, such as telecommunication lasers and as single-photon sources for quantum cryptography.
Saturday, October 11, 2014
Friday, October 10, 2014
'How can a beam of light tell the difference between left and right? Tiny particles have now been coupled to a glass fiber. The particles emit light into the fiber in such a way that it does not travel in both directions, as one would expect. Instead, the light can be directed either to the left or to the right. This has become possible by employing a remarkable physical effect – the spin-orbit coupling of light. This new kind of optical switch has the potential to revolutionize nanophotonics.'
Looks like a Diode for light
Thursday, October 9, 2014
'Fusion energy almost sounds too good to be true -- zero greenhouse gas emissions, no long-lived radioactive waste, a nearly unlimited fuel supply.
Perhaps the biggest roadblock to adopting fusion energy is that the economics haven't penciled out. Fusion power designs aren't cheap enough to outperform systems that use fossil fuels such as coal and natural gas.
University of Washington engineers hope to change that. They have designed a concept for a fusion reactor that, when scaled up to the size of a large electrical power plant, would rival costs for a new coal-fired plant with similar electrical output.
Monday, October 6, 2014
'A new study published in the Cell Press journal Current Biology on October 2 could rewrite the story of ape and human brain evolution. While the neocortex of the brain has been called "the crowning achievement of evolution and the biological substrate of human mental prowess," newly reported evolutionary rate comparisons show that the cerebellum expanded up to six times faster than anticipated throughout the evolution of apes, including humans.
Wednesday, October 1, 2014
The problem is that we have pretty good evidence that black holes do
exist. If they don't exist then we have some explaining to do.
Years ago I saw how a few scientific dissenters theorized that black
holes were really just neutron stars, which is kind of like "black
hole-lite". However neutron stars couldn't account for the evidence
of billion solar mass black holes at the center of every galaxy.