Grand Canyon much younger than previously thought?

The Grand Canyon took its present form just five to six million years ago — more recently than previously thought, a new study suggests. Previous studies had claimed that the canyon, which snakes through the US state of Arizona, was 70 million years old. The latest study agrees that some segments are very old, but the full system is quite young. "The 'old canyon model' has argued that the Grand Canyon was carved 70 million years ago. We are refuting that," said Karl Karlstrom from the University of New Mexico, Albuquerque. "We are also refuting the 'young canyon model', which claims the canyon was cut entirely in the last six million years. We show that the Colorado River used some old segments as it found its path to the Gulf of California in the past six million years." The experts used thermochronology to ascertain timing of the formation of four of the canyon's five segments. It was found that two of the three central segments — known as the 'Hurricane' segment and the 'Eastern Grand Canyon' — were ancient. While the 'Hurricane' segment was formed 50 to 70 million years ago, the 'Eastern Grand Canyon' was incised 15 to 25 million years ago. The researchers say the two end segments of the canyon — known as the 'Marble' and the 'Westernmost Grand Canyon' — were carved in the last five to six million years.

26 pledges I take with Speaking Tree

On the 65th Republic day let’s agree to not to crib or rant about India but to make this day, the first verse in shaping our country. Speaking Tree invites you to take 26 pledges this 26th January, that will make the crucial difference between what India is and what it can be! So let us get together and be led by action and not rhetoric. Take the SpeakingTree Ipledge now and spread the good word by sharing this with as many people as you can… http://www.speakingtree.in/ipledge

Diseases, fights led to collapse of Indus civilization

Inter-personal violence and infectious diseases played a role around 4,000 years ago in the collapse of the Indus civilization that spanned over a million sq km of India and Pakistan, a new study suggests. While contemporaneous civilizations in Egypt and Mesopotomia are well-known their Indus trading partners have remained more of a mystery, researchers said. Archaeological research has demonstrated that Indus cities grew rapidly from 2200-1900 BC, when they were largely abandoned. "The collapse of the Indus civilization and the reorganization of its human population has been controversial for a long time," lead author of the study, Gwen Robbins Schug, from the Appalachian State University, US, said. Climate, economic, and social changes all played a role in the process of urbanization and collapse, but little was known about how these changes affected the human population. Robbins Schug and an international team of researchers examined evidence for trauma and infectious disease in the human skeletal remains from three burial areas at Harappa, one of the largest cities in the Indus civilization. The results of their analysis counter longstanding claims that the Indus civilization developed as a peaceful, cooperative, and egalitarian state-level society, without social differentiation, hierarchy, or differences in access to basic resources. The data suggest instead that some communities at Harappa faced more significant impacts than others from climate and socio-economic strains, particularly the socially disadvantaged or marginalised communities who are most vulnerable to violence and disease.

Decoded: Why birds form a V to fly

LONDON: Birds fly in a distinctive V formation to arrange themselves in "aerodynamically optimum positions" while precisely timing the flapping of their wings, scientists have found. Flying in a V formation helps each bird take advantage of "good air" (upwash) thrown up by the wings of the flyer in front while avoiding detrimental 'bad air' (downwash), according to researchers from the University of London's Royal Veterinary College . They found that birds also flap their wings at just the right time so as maximize an updraft and minimise a downdraft. These aerodynamic accomplishments were previously not thought possible for birds because of the complex flight dynamics and sensory feedback that would be required to perform such a feat, researchers said. "The distinctive V-formation of bird flocks has long intrigued researchers and continues to attract both scientific and popular attention, however adefinitive account of the aerodynamic implications of these formations has remained elusive until now," said Steven Portugal, lead researcher at the Royal Veterinary College. "The intricate mechanisms involved in V formation flight indicate remarkable awareness and ability of birds to respond to the wingpath of nearby flock-mates . "Birds in V formation seem to have developed complex phasing strategies to cope with the dynamic wakes produced by flapping wings," Portugal said. Researchers studied a free-flying flock of northern bald ibises as they flew alongside a microlight on their migration route from Austria to Italy

Now, send your name to asteroid on Nasa’s chip

WASHINGTON: So what if you can't go to space? You can send your name there! US space agency Nasa is inviting people around the world to submit their names to be etched on a microchip aboard a spacecraft headed to an asteroid in 2016. The microchip will travel to the asteroid, named Bennu, aboard the agency's Origins-Spectral Interpretation Resource Identification Security Regolith Explorer (OSIRIS-REx ) spacecraft. The robotic mission will spend more than two years at the 1,760-foot-wide asteroid. The spacecraft will collect a sample of Bennu's surface and return it to Earth in a sample return capsule. "We're thrilled to be able to share the OSIRISREx adventure with people across the Earth, to Bennu and back," said Dante Lauretta, principal investigator of the OSIRIS-REx mission from the University of Arizona. "It's a great opportunity for people to get engaged with the mission and join us for launch," she said. Those wishing to participate in "Messages to Bennu !"should submit their name online by Sept 30