Nuclear power
The world’s first large-scale nuclear power plant opened at Calder Hall in Cumbria, England, in 1956 and produced electricity for 47 years.
In 1572, people on Earth saw the bright light of a supernova. Now, by combining different intensities of x-ray data, scientists using NASA’s Chandra X-ray Observatory have created a new image of the debris left from that explosion, which hints at the origins of the cosmic blast.
Known as Tycho’s supernova remnant, the space puffball includes a cloud of expanding debris (yellow) enveloped by a high-energy blast wave (blue). The latest image also shows an arc of high-energy x-rays (bottom left) that seems to be coming from a faster moving ball of material.
Astronomers think that the supernova happened when a white dwarf star siphoned so much material from a companion star that it exploded. The blast blew material off the sunlike companion, and that debris is now emitting the arc of x-rays.
NASA’s Mars Reconnaissance Orbiter has discovered the total amount of atmosphere on Mars changes dramatically as the tilt of the planet’s axis varies. This process can affect the stability of liquid water, if it exists on the Martian surface, and increase the frequency and severity of Martian dust storms.
With a leg span of more than five inches, a recently named Jurassic period spider from China is the largest fossil specimen discovered, and one that has modern relatives in tropical climates today.
Research released in anticipation of World Malaria Day finds that plants in East Africa with promising antimalarial qualities — ones that have treated malaria symptoms in the region’s communities for hundreds of years — are at risk of extinction. Scientists fear that these natural remedial qualities, and thus their potential to become a widespread treatment for malaria, could be lost forever.
A new book by researchers at the World Agroforestry Centre (ICRAF) and the Kenya Medical Research Institute (KEMRI), Common Antimalarial Trees and Shrubs of East Africa, provides a detailed assessment of 22 of the region’s malaria-fighting trees and shrubs. While over a thousand plant species have been identified by traditional healers as effective in the prevention or treatment of malaria symptoms, the species in the book were assigned by both traditional medicinal practitioners and scientists as those that have potential for further study.
Two-thirds of the Arctic coastline is made of permafrost — an environment that is very sensitive to warming temperatures. A new report says erosion is causing these coastline regions to recede by an average of 1.5 feet per year.
Unlike rock shoreline, permafrost loses its structure when it warms above freezing. “Surface air temperatures have reached record levels over the past decade,” the report from an international consortium found. Combine this with weakened permafrost and there’s a recipe for erosion.
Psychologists from The University of Auckland have just published two major studies on the diversity of the world’s languages in the journals Science and Nature.
The first study, published in Scienceby Dr Quentin Atkinson, provides strong evidence for Africa as the birthplace of human language.
An analysis of languages from around the world suggests that, like our genes, human speech originated — just once — in sub-Saharan Africa. Atkinson studied the phonemes, or the perceptually distinct units of sound that differentiate words, used in 504 human languages today and found that the number of phonemes is highest in Africa and decreases with increasing distance from Africa.
The fewest phonemes are found in South America and on tropical islands in the Pacific Ocean. This pattern fits a “serial founder effect” model in which small populations on the edge of an expansion progressively lose diversity. Dr Atkinson notes that this pattern of phoneme usage around the world mirrors the pattern of human genetic diversity, which also declined as humans expanded their range from Africa to colonise other regions.
In general, the areas of the globe that were most recently colonised incorporate fewer phonemes into the local languages whereas the areas that have hosted modern humans for millennia (particularly sub-Saharan Africa) still use the most phonemes.
This decline in phoneme usage cannot be explained by demographic shifts or other local factors, and it provides strong evidence for an African origin of modern human languages — as well as parallel mechanisms that slowly shaped both genetic and linguistic diversity among humans.
The second study, published in Nature by University of Auckland researchers Professor Russell Gray and Dr Simon Greenhill and their colleagues Michael Dunn and Stephen Levinson at the Max Planck Institute for Psycholinguistics in the Netherlands challenges the idea that the human brain produces universal rules for language.
“There are about 7,000 languages spoken today, some with just a dozen contrastive sounds, others with more than 100, some with complex patterns of word formation, others with simple words only, some with the verb at the beginning of the sentence, some in the middle, and some at the end.”
“Our work shows that the claims some linguists have made for a really strong role of the innate structure of the human mind in shaping linguistic variation have been hugely oversold,” he says.
Using computational methods derived from evolutionary biology, Gray and his team analysed the global patterns of word-order evolution. Instead of universal patterns of dependencies in word-order features, they found that each language family had its own evolutionary tendencies.
“When it comes to language evolution, culture trumps cognition,” Gray observes.
Bacteria slowly built the mounds, known as stromatolites, layer by layer on the lake bottom. The lumps, which look like oversized traffic cones, resemble similar structures that first appeared billions of years ago and remain in fossil form as one of the oldest widespread records of ancient life. The Antarctic discovery could thus help scientists better understand the conditions under which primitive life-forms thrived. “It’s like going back to early Earth,” says Dawn Sumner, a geobiologist at the University of California, Davis.
The closest approach is called perigee, while the greatest separation is called apogee.
On average, the moon’s distance from Earth is 239,228 miles (385,000 kilometers).