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Pulsars feel swoosh as companions whizz past
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Domhnall Malone
GIVE graphene a diamond and you’ll get a flower in return. Poking a sheet of atom-thick graphene with a diamond tool prompts tiny ribbons to peel away from the surface, like flower petals opening. “I don’t think anyone ever expected it,” says Graham Cross at Trinity College Dublin, Ireland. Graphene sheets, which are made of a single layer of carbon atoms, are both super-strong and highly flexible. Other teams have folded graphene into origami shapes using chemical reactions, and made tiny tools. Cross and his colleagues accidentally discovered graphene’s hidden talent while trying to measure its friction by piercing it. Once their diamond tip punctured the sheet, the energy from ambient heat kept the ribbons tearing into a tapered strip – a process that took less than a minute. By changing the initial width of the tear, the researchers could control the length of the ribbons, which tended to grow to five times their initial width (Nature, DOI: bmqd). Graphene’s self-folding ability could help make better electronics, says Cross. By setting off ribbon formation in careful patterns, the sheets could be turned into sensors and even transistors, allowing for nanoscale electronics.
Pulsars feel swoosh as companions whizz past TWO strange celestial bodies might have the clingiest friends in the cosmos. If a pair of pulsars are orbited by very dense objects once every few minutes, that might explain a strange repeating pattern interrupting the stars’ radio signals. Pulsars, aka spinning neutron stars, normally emit radio pulses like clockwork. But Joanna Rankin at the University of Vermont in Burlington noticed another pattern she calls a “swoosh”, when signals from certain pulsars arrived sooner than expected.
Minutes later, the signal drifted back to normal. Further observations showed these swooshes sometimes repeat. Now, a study led by Rankin’s student Haley Wahl suggests companion objects orbiting the pulsars at close range could trigger the swoosh. These unseen neighbours, if they exist, must orbit the pulsars at breakneck speed once every few minutes – a shorter orbital period than for any known pair of objects in the universe, says Rankin. By passing through the pulsar’s
magnetic field at such a rapid pace, these companions could create the swoosh by disrupting the radio signal we see (arxiv.org/ abs/1607.01737v1). Such a companion must be something special, though, like a small black hole or a hunk of white-dwarf matter. Most ordinary objects would be ripped to shreds by the pulsar’s gravity. “It has to be something incredibly dense to stay together,” says Rankin. “Even a rock of normal material couldn’t do anything but turn into dust.” Atlantide Phototravel/Getty
Graphene unfolds into nano-flowers
Ducklings dabble in abstract thought THERE once was a brainy duckling. It could remember whether the shapes or colours it saw just after hatching were the same as each other or different. This feat surprised University of Oxford researchers, who initially doubted that ducklings could grasp complex concepts such as “same” and “different”. The fact that they could do so suggests that the ability to think in an abstract way may be more common in nature than we might expect, and not just restricted to humans and a handful of animals with big brains. Ducklings instinctively follow the first things they see, usually a mother and siblings. So Alex Kacelnik and Antone Martinho presented them with a pair of objects that were either the same or different in shape and colour. Later, they offered the ducklings the choice of following combinations of “same” or “different” objects. Of the 113 ducklings in the experiment, 77 trailed the colour or shape pairing that corresponded to the combination of “same” or “different” they were primed with after hatching (Science, doi.org/bmk9).
Perfect harmony? It’s a matter of taste THERE’S no such thing as a nasty-sounding chord: it all depends on what you’re used to. The ancient Greeks discovered that musical harmony seems to be rooted in mathematics, and today we know that many cultures worldwide use mathematically neat chords. But Josh McDermott at the Massachusetts Institute of Technology and his team have evidence that a preference for mathematically simple harmonies is not innate. They played “consonant” note combinations – such as perfect fifths – and dissonant combinations,
which are not so mathematically simple and sound harsher to Western ears, to 160 people from the US and Bolivia, and asked them to rate how pleasant each one sounded. The participants from the US found consonant combinations more pleasant than dissonant ones. But people who belonged to the Tsimane – a native Amazonian society in Bolivia – showed no such preference (Nature, doi.org/bmk3). “The preference for consonance over dissonance varied roughly in line with the degree of exposure to Western music,” says McDermott.
23 July 2016 | NewScientist | 15
Domhnall Malone
GIVE graphene a diamond and you’ll get a flower in return. Poking a sheet of atom-thick graphene with a diamond tool prompts tiny ribbons to peel away from the surface, like flower petals opening. “I don’t think anyone ever expected it,” says Graham Cross at Trinity College Dublin, Ireland. Graphene sheets, which are made of a single layer of carbon atoms, are both super-strong and highly flexible. Other teams have folded graphene into origami shapes using chemical reactions, and made tiny tools. Cross and his colleagues accidentally discovered graphene’s hidden talent while trying to measure its friction by piercing it. Once their diamond tip punctured the sheet, the energy from ambient heat kept the ribbons tearing into a tapered strip – a process that took less than a minute. By changing the initial width of the tear, the researchers could control the length of the ribbons, which tended to grow to five times their initial width (Nature, DOI: bmqd). Graphene’s self-folding ability could help make better electronics, says Cross. By setting off ribbon formation in careful patterns, the sheets could be turned into sensors and even transistors, allowing for nanoscale electronics.
Pulsars feel swoosh as companions whizz past TWO strange celestial bodies might have the clingiest friends in the cosmos. If a pair of pulsars are orbited by very dense objects once every few minutes, that might explain a strange repeating pattern interrupting the stars’ radio signals. Pulsars, aka spinning neutron stars, normally emit radio pulses like clockwork. But Joanna Rankin at the University of Vermont in Burlington noticed another pattern she calls a “swoosh”, when signals from certain pulsars arrived sooner than expected.
Minutes later, the signal drifted back to normal. Further observations showed these swooshes sometimes repeat. Now, a study led by Rankin’s student Haley Wahl suggests companion objects orbiting the pulsars at close range could trigger the swoosh. These unseen neighbours, if they exist, must orbit the pulsars at breakneck speed once every few minutes – a shorter orbital period than for any known pair of objects in the universe, says Rankin. By passing through the pulsar’s
magnetic field at such a rapid pace, these companions could create the swoosh by disrupting the radio signal we see (arxiv.org/ abs/1607.01737v1). Such a companion must be something special, though, like a small black hole or a hunk of white-dwarf matter. Most ordinary objects would be ripped to shreds by the pulsar’s gravity. “It has to be something incredibly dense to stay together,” says Rankin. “Even a rock of normal material couldn’t do anything but turn into dust.” Atlantide Phototravel/Getty
Graphene unfolds into nano-flowers
Ducklings dabble in abstract thought THERE once was a brainy duckling. It could remember whether the shapes or colours it saw just after hatching were the same as each other or different. This feat surprised University of Oxford researchers, who initially doubted that ducklings could grasp complex concepts such as “same” and “different”. The fact that they could do so suggests that the ability to think in an abstract way may be more common in nature than we might expect, and not just restricted to humans and a handful of animals with big brains. Ducklings instinctively follow the first things they see, usually a mother and siblings. So Alex Kacelnik and Antone Martinho presented them with a pair of objects that were either the same or different in shape and colour. Later, they offered the ducklings the choice of following combinations of “same” or “different” objects. Of the 113 ducklings in the experiment, 77 trailed the colour or shape pairing that corresponded to the combination of “same” or “different” they were primed with after hatching (Science, doi.org/bmk9).
Perfect harmony? It’s a matter of taste THERE’S no such thing as a nasty-sounding chord: it all depends on what you’re used to. The ancient Greeks discovered that musical harmony seems to be rooted in mathematics, and today we know that many cultures worldwide use mathematically neat chords. But Josh McDermott at the Massachusetts Institute of Technology and his team have evidence that a preference for mathematically simple harmonies is not innate. They played “consonant” note combinations – such as perfect fifths – and dissonant combinations,
which are not so mathematically simple and sound harsher to Western ears, to 160 people from the US and Bolivia, and asked them to rate how pleasant each one sounded. The participants from the US found consonant combinations more pleasant than dissonant ones. But people who belonged to the Tsimane – a native Amazonian society in Bolivia – showed no such preference (Nature, doi.org/bmk3). “The preference for consonance over dissonance varied roughly in line with the degree of exposure to Western music,” says McDermott.
23 July 2016 | NewScientist | 15