Human aerial bombardments might have pushed Neanderthals to extinction, suggests new research. Changes in bone shape left by a life of overhand throwing hint that Stone Age humans regularly threw heavy objects, such as stones or spears, while Neanderthals did not.
"The anatomically modern humans would have this more effective and efficient form of hunting," says Jill Rhodes, a biological anthropologist at Bryn Mawr College in Pennsylvania, who led the new study. A warmer Europe would have opened up forests, enabling longer range hunting, she says.
Rhodes and a colleague studied changes to the arm bone that connects the shoulder to the elbow - the humerus - to determine when humans may have begun using projectile weapons.
Science & Technology
© Roger Wesson / University College London
V458 Vul: Images taken in May 2008 (top) and September 2008 (bottom) show the dramatic changes occurring in the nebula as a result of the central star's explosion
V458 Vul: Images taken in May 2008 (top) and September 2008 (bottom) show the dramatic changes occurring in the nebula as a result of the central star's explosion
A planetary nebula is an astronomical object consisting of a glowing shell of gas and plasma formed by many stars as they approach the end of their lives, while a nova is a cataclysmic nuclear explosion caused by the accretion of hydrogen onto the surface of a nearly-dead white dwarf star in a close binary.
Distance crushes perspective. Objects hurtle through space at mind-numbing speeds, some moving so quickly they could cross the United States in just seconds; yet, due to their distance, we could wait thousands of years to be able to perceive their motion at all.
Unless, that is, they leave behind some tell-tale sign of their rapid movement. Space is not empty, and a star plowing through this ethereally thin gas at dozens of kilometers per second reveals itself. The gas gets compressed ahead of the star, and flows around it in graceful arcs. Like water flowing around the bow of a ship, such a formation is called a bow shock.
This shock wave can be invisible to the unaided eye, but when we train infrared telescopes on them they leap out of the picture. Behold the bow shock of Betelgeuse:
Unless, that is, they leave behind some tell-tale sign of their rapid movement. Space is not empty, and a star plowing through this ethereally thin gas at dozens of kilometers per second reveals itself. The gas gets compressed ahead of the star, and flows around it in graceful arcs. Like water flowing around the bow of a ship, such a formation is called a bow shock.
This shock wave can be invisible to the unaided eye, but when we train infrared telescopes on them they leap out of the picture. Behold the bow shock of Betelgeuse:
Nicolaus Copernicus
The findings could put an end to centuries of speculation about the exact resting spot of Copernicus, a priest and astronomer whose theories identified the Sun, not the Earth, as the center of the solar system.
Polish archaeologist Jerzy Gassowski told a news conference that forensic facial reconstruction of the skull that his team found in 2005 buried in a Roman Catholic Cathedral in Frombork, Poland, bears striking resemblance to existing portraits of Copernicus.
The promise of quantum computing is that it will dramatically outshine traditional computers in tackling certain key problems: searching large databases, factoring large numbers, creating uncrackable codes and simulating the atomic structure of materials.
© RolexAwards/Marc Latzel
Geophysicist Andrew McGonigle on Vulcano Island, Italy with his prototype helicopter.
Geophysicist Andrew McGonigle on Vulcano Island, Italy with his prototype helicopter.
A large toy helicopter could help to predict volcanic eruptions in time to safely evacuate the surrounding area, according to geophysicists who have just been awarded $100,000 to develop their idea.
When fresh, eruption-ready magma arrives deep in the heart of a volcano, it tends to release carbon dioxide. As the magma rises, it also pushes sulfur dioxide out of the volcano. Spotting changes in the ratio of these gases around a volcano should indicate whether it is about to blow - but although sulfur dioxide is routinely measured by vulcanologists, taking carbon dioxide measurements is a much bigger challenge.
WANTED: Rocky planet outside of our solar system. Must not be too hot or too cold, but just the right temperature to support life.
It sounds like a simple enough wish list, but finding a planet that fulfils all of these criteria has kept astronomers busy for decades. Until recently, it meant finding a planet in the "Goldilocks zone" - orbiting its star at just the right distance to keep surface water liquid rather than being boiled off or frozen solid.
Now, though, it's becoming increasingly clear that the question of what makes a planet habitable is not as simple as finding it in just the right spot. Many other factors, including a planet's mass, atmosphere, composition and the way it orbits its nearest star, can all influence whether it can sustain liquid water, an essential ingredient for life as we know it. As astronomers explore newly discovered planets and create computer simulations of virtual worlds, they are discovering that water, and life, might exist on all manner of weird worlds where conditions are very different from those on Earth. And that means there could be vastly more habitable planets out there than we thought possible. "It's like science fiction, only better," says Raymond Pierrehumbert, a climate scientist at the University of Chicago, who studies planets inside and outside of our solar system.
It sounds like a simple enough wish list, but finding a planet that fulfils all of these criteria has kept astronomers busy for decades. Until recently, it meant finding a planet in the "Goldilocks zone" - orbiting its star at just the right distance to keep surface water liquid rather than being boiled off or frozen solid.
Now, though, it's becoming increasingly clear that the question of what makes a planet habitable is not as simple as finding it in just the right spot. Many other factors, including a planet's mass, atmosphere, composition and the way it orbits its nearest star, can all influence whether it can sustain liquid water, an essential ingredient for life as we know it. As astronomers explore newly discovered planets and create computer simulations of virtual worlds, they are discovering that water, and life, might exist on all manner of weird worlds where conditions are very different from those on Earth. And that means there could be vastly more habitable planets out there than we thought possible. "It's like science fiction, only better," says Raymond Pierrehumbert, a climate scientist at the University of Chicago, who studies planets inside and outside of our solar system.
© T Gregory Guzik
A balloon-borne experiment flying over Antarctica measured a surprisingly high number of energetic electrons streaming in from space.
A balloon-borne experiment flying over Antarctica measured a surprisingly high number of energetic electrons streaming in from space.
High-energy electrons are found throughout space and are accelerated when stars explode in supernovae. But a balloon-borne detector flying over Antarctica called the Advanced Thin Ionization Calorimeter (ATIC) has detected 70 more high-energy electrons than the normal background level attributed to supernova blasts.
John Wefel of Louisiana State University in Baton Rouge, who led the collaboration, says there are two possible explanations.
The electrons could come from a nearby astrophysical object, such as a pulsar, that lies within 3000 light years from Earth. But the team has spent four years trying to fit the signal to such an object and has yet to find a good match.
Tufts of frozen woolly mammoth hair have yielded a rough draft of its genome. It's the most successful attempt to sequence the DNA of an extinct ancient animal to date, and although we won't see resurrected mammoths grazing the tundra anytime soon, it could give us a peek into the reasons for their extinction.
Sequencing extinct organisms is tricky since DNA strands quickly degrade after death into short fragments that are difficult to piece back together. In porous tissue like bone, these fragments can also become flooded by DNA from bacteria and fungi growing on the decomposing body, making it hard to pick out the genetic material of interest.
To solve this, Stephan Schuster from Pennsylvania State University and colleagues sequenced DNA from the hair of two frozen woolly mammoths, which died in Siberia roughly 20,000 and 60,000 years ago respectively.
Sequencing extinct organisms is tricky since DNA strands quickly degrade after death into short fragments that are difficult to piece back together. In porous tissue like bone, these fragments can also become flooded by DNA from bacteria and fungi growing on the decomposing body, making it hard to pick out the genetic material of interest.
© Peter Brooker/Rex Features
Mammoth hair protects DNA from the ravages of nature.
Mammoth hair protects DNA from the ravages of nature.
To solve this, Stephan Schuster from Pennsylvania State University and colleagues sequenced DNA from the hair of two frozen woolly mammoths, which died in Siberia roughly 20,000 and 60,000 years ago respectively.
When a researcher noticed that bass notes from his MP3 player were making drops of liquid bounce, it began the development of a new technique to levitate droplets, thus keeping them from contamination by surfaces.
In theory, scientists could learn a lot about our health by testing tiny amounts of bodily fluids - a drop of blood, a tear, a bead of sweat. But something this small is easily contaminated by other liquids or surfaces. So what are scientists doing? They're making liquids bounce, dance, and float lightly through the air. Researchers from Belgium's University of Liege published their findings November 18th in the New Journal of Physics.
In theory, scientists could learn a lot about our health by testing tiny amounts of bodily fluids - a drop of blood, a tear, a bead of sweat. But something this small is easily contaminated by other liquids or surfaces. So what are scientists doing? They're making liquids bounce, dance, and float lightly through the air. Researchers from Belgium's University of Liege published their findings November 18th in the New Journal of Physics.
