- Email: [email protected]
3D atomic clock is most precise ever
IN BRIEF
FRANS LANTING/NATIONAL GEOGRAPHIC CREATIVE
IT’S not every day that an aerospace engineer raises new questions about bird flight. But Abdessattar Abdelkefi and his team at New Mexico State University did just that while trying to devise better drones. Many large soaring birds like the albatross have wings that are white underneath and black on top. Previous explanations focused on camouflage, says Graham Martin at the University of Birmingham, UK. But does that colouring really boost endurance in flight? Most soaring needs no flapping of wings; instead, the bird exploits air currents to glide. Abdelkefi’s team discovered that a wing’s black upper surface absorbs sunlight very efficiently, causing it to be around 10°C warmer than the lower surface. That effectively lowers air pressure on the upper surface, lowering drag and generating extra lift (Journal of Thermal Biology, doi.org/f96ggw). Svana Rogalla at the University of Ghent, Belgium, says thermography has proved that the dark upper wing gets hotter in sunlight, but it is too early to pin down its effect on drag. The impact of colour on flight could be a further inducement for birds to make costly melanin pigment to darken feathers, she says. The team hopes the findings will help them design more efficient and durable drones for use at sea.
18 | NewScientist | 14 October 2017
Hot gas from lava lakes gave the early moon an atmosphere MASSIVE volcanic eruptions on the surface of the moon 3.5 billion years ago released enough hot gas to create an atmosphere that took 70 million years to leak away. We knew that the magma ocean covering the newborn moon 4.5 billion years ago released vapours of sodium and silica that formed a short-lived atmosphere. Now it seems a second one arose 1 billion years later due to eruptions flooding a large crater to form the lava plain Mare Imbrium. Recent studies have revealed volatile material embedded in
lunar volcanic glass collected by Apollo astronauts. The glass hinted that the large volcanic eruptions that formed the lunar basins 3.8 to 3.1 billion years ago also emitted large amounts of gas. Debra Needham and David Kring at the Lunar and Planetary Institute in Houston, Texas, have calculated these emissions based on the estimated volumes of the lava flows. The largest emission was the roughly 10 trillion tonnes of gases that erupted along with the 5.3 million cubic kilometres of lava that filled the Imbrium basin.
That would have raised lunar air pressure to about 1 per cent that of modern Earth, or 1.5 times as dense as the atmosphere on Mars today (Earth and Planetary Science Letters, doi.org/cdww). Within 70 million years, all the atmospheric gas escaped or froze out in the polar regions. James Day of the Scripps Institution of Oceanography in California says this atmosphere formation process could account for the distribution of water and other volatiles on the surface of the moon. GARRY BURCHELL/GETTY
Albatross teaches drones new tricks
For new stories every day, visit newscientist.com/news
3D atomic clock is most precise ever THE most accurate atomic clock yet has been made by putting strontium atoms in grid-like patterns and stacking them. Most atomic clocks use atoms of the isotope caesium-133. Time is measured in microwaves emitted by the electrons around those atoms jumping from a lower to higher orbit as they absorb and then lose energy from a laser. But caesium electrons have a speed limit: they can only jump back and forth 9 billion times per second. The electrons in strontium atoms can transition nearly 1 million billion times per second. Jun Ye at the University of Colorado at Boulder and his team built a strontium clock so precise that out of every 10 quintillion ticks only 3.5 would be out of sync – the first atomic clock ever to reach that level of precision (Science, doi.org/cdwx). The team put atoms into a 3D lattice structure that let them measure more atomic signals at once within the width of the laser beam. They cooled the structure to -273˚C, which turned the atoms into what’s called a quantum gas. Instead of colliding, the particles “move like waves – they start to avoid each other,” Ye says.
Train your brain with meditation DIFFERENT types of meditation have distinct effects on the brain. Tania Singer at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany, and colleagues looked at how three meditation techniques affected the brains and bodies of more than 300 volunteers over nine months. One technique was based on mindfulness meditation, a second concentrated on compassion and emotional connection with a partner. A final method encouraged people to think about issues from different points of view. MRI scans taken after
each three-month course showed that parts of the cortex involved in the specific skill that was trained grew thicker in comparison with scans of a control group. For example, mindfulness increased the thickness of the prefrontal cortex and parietal lobes, which are linked to attention control. All the brain changes were matched by improvements in tests of the relevant skills (Science Advances, doi.org/cdw7). The study suggests meditation courses could be designed like exercise regimes, focusing on particular weaknesses.
FRANS LANTING/NATIONAL GEOGRAPHIC CREATIVE
IT’S not every day that an aerospace engineer raises new questions about bird flight. But Abdessattar Abdelkefi and his team at New Mexico State University did just that while trying to devise better drones. Many large soaring birds like the albatross have wings that are white underneath and black on top. Previous explanations focused on camouflage, says Graham Martin at the University of Birmingham, UK. But does that colouring really boost endurance in flight? Most soaring needs no flapping of wings; instead, the bird exploits air currents to glide. Abdelkefi’s team discovered that a wing’s black upper surface absorbs sunlight very efficiently, causing it to be around 10°C warmer than the lower surface. That effectively lowers air pressure on the upper surface, lowering drag and generating extra lift (Journal of Thermal Biology, doi.org/f96ggw). Svana Rogalla at the University of Ghent, Belgium, says thermography has proved that the dark upper wing gets hotter in sunlight, but it is too early to pin down its effect on drag. The impact of colour on flight could be a further inducement for birds to make costly melanin pigment to darken feathers, she says. The team hopes the findings will help them design more efficient and durable drones for use at sea.
18 | NewScientist | 14 October 2017
Hot gas from lava lakes gave the early moon an atmosphere MASSIVE volcanic eruptions on the surface of the moon 3.5 billion years ago released enough hot gas to create an atmosphere that took 70 million years to leak away. We knew that the magma ocean covering the newborn moon 4.5 billion years ago released vapours of sodium and silica that formed a short-lived atmosphere. Now it seems a second one arose 1 billion years later due to eruptions flooding a large crater to form the lava plain Mare Imbrium. Recent studies have revealed volatile material embedded in
lunar volcanic glass collected by Apollo astronauts. The glass hinted that the large volcanic eruptions that formed the lunar basins 3.8 to 3.1 billion years ago also emitted large amounts of gas. Debra Needham and David Kring at the Lunar and Planetary Institute in Houston, Texas, have calculated these emissions based on the estimated volumes of the lava flows. The largest emission was the roughly 10 trillion tonnes of gases that erupted along with the 5.3 million cubic kilometres of lava that filled the Imbrium basin.
That would have raised lunar air pressure to about 1 per cent that of modern Earth, or 1.5 times as dense as the atmosphere on Mars today (Earth and Planetary Science Letters, doi.org/cdww). Within 70 million years, all the atmospheric gas escaped or froze out in the polar regions. James Day of the Scripps Institution of Oceanography in California says this atmosphere formation process could account for the distribution of water and other volatiles on the surface of the moon. GARRY BURCHELL/GETTY
Albatross teaches drones new tricks
For new stories every day, visit newscientist.com/news
3D atomic clock is most precise ever THE most accurate atomic clock yet has been made by putting strontium atoms in grid-like patterns and stacking them. Most atomic clocks use atoms of the isotope caesium-133. Time is measured in microwaves emitted by the electrons around those atoms jumping from a lower to higher orbit as they absorb and then lose energy from a laser. But caesium electrons have a speed limit: they can only jump back and forth 9 billion times per second. The electrons in strontium atoms can transition nearly 1 million billion times per second. Jun Ye at the University of Colorado at Boulder and his team built a strontium clock so precise that out of every 10 quintillion ticks only 3.5 would be out of sync – the first atomic clock ever to reach that level of precision (Science, doi.org/cdwx). The team put atoms into a 3D lattice structure that let them measure more atomic signals at once within the width of the laser beam. They cooled the structure to -273˚C, which turned the atoms into what’s called a quantum gas. Instead of colliding, the particles “move like waves – they start to avoid each other,” Ye says.
Train your brain with meditation DIFFERENT types of meditation have distinct effects on the brain. Tania Singer at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany, and colleagues looked at how three meditation techniques affected the brains and bodies of more than 300 volunteers over nine months. One technique was based on mindfulness meditation, a second concentrated on compassion and emotional connection with a partner. A final method encouraged people to think about issues from different points of view. MRI scans taken after
each three-month course showed that parts of the cortex involved in the specific skill that was trained grew thicker in comparison with scans of a control group. For example, mindfulness increased the thickness of the prefrontal cortex and parietal lobes, which are linked to attention control. All the brain changes were matched by improvements in tests of the relevant skills (Science Advances, doi.org/cdw7). The study suggests meditation courses could be designed like exercise regimes, focusing on particular weaknesses.