Stars' flickers reveal their inner selves
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In brief – Research news and discovery JOEL SAGET/AFP/GETTY CAN a pendulum swing in space? It might if it is quantum powered, a fact that could be exploited to build tiny timepieces that run off the quantum fluctuations that occur in a vacuum. Habibollah Ramzi and Mah Abdollahi from the University of Qom, Iran, envisaged a tiny pendulum made with a string of 30 atoms attached to a conducting plate at one end. They calculated that the Casimir-Polder force – which arises from the exchange of the “virtual” photons that pop in and out of existence in a vacuum – would attract the nanostring towards the plate. Before it touched the plate, however, the forces between its atoms would force it back. The cycle would repeat, causing the nanostring to swing like a pendulum (Physics Letters A, DOI: 10.1016/j.physleta.2008.09.040). Traditional pendulums rely on gravity to regulate their swing, but gravity varies with position in space. The Casimir-Polder force, however, is the same everywhere. Roberto Onofrio of the University of Padua, Italy, believes this could make a vacuum clock useful on spacecraft. Yet it will be hard to build one, says Thomas Valone of the Integrity Research Institute in Beltsville, Maryland, because the string would probably twist or stretch as well as swing. Tick, tock goes the nanostring clock PURPLE tomatoes will certainly jazz up a ratatouille but they could also protect against cancer. All tomato plants have the genes to produce anthocyanins – purple pigments found in blueberries that mop up cancer- causing free radicals – but they are dormant. To activate them, Eugenio Butelli’s team from the John Innes Centre in Norwich, UK‚ inserted two genes from the snapdragon flower. The resulting fruit increased the lifespans of mice engineered to have cancer (Nature Biotechnology, DOI: 10.1038/nbt.1506). Previous attempts to engineer tomatoes with anthocyanins produced low levels in the skin only, says Butelli. His team’s tomatoes have high levels throughout the fruit. Purple that’s not just skin deep FLUCTUATIONS in the brightness of distant stars, measured in finer detail than ever before, are offering unexpected insights into what is going on inside them. A team led by Eric Michel of the Paris Observatory in France used the CoRoT spacecraft to measure subtle variations in the brightness of three stars. The fluctuations, caused by vibrations in the surface of the star, were 25 per cent weaker than expected. This suggests that astronomers need to refine their ideas of how energy is transformed on stellar surfaces, Michel says ( Science, vol 322, p 558). The variations in brightness also provide evidence of stars’ internal structure and age, as changes in the stars’ composition over time should affect how they vibrate. “This marks the start of a new era of space-based asteroseismology,” says Jørgen Christensen-Dalsgaard of the University of Aarhus in Denmark. Telling twinkles THE iron will you need to bounce back and win in sport, or pass exams even when the chips are down, may be largely inherited. Tenacious winners – such as cyclist Lance Armstrong (pictured), who recovered from testicular cancer and went on to win the Tour de France seven times – are naturally tough, a new study suggests, and it may be difficult to boost people who are not naturally resilient. Tony Vernon at the University of Western Ontario in London, Canada, led a questionnaire-based study of 219 pairs of twins which probed the genetic and environmental contributions of four traits associated with mental toughness: control over life, commitment, confidence and the ability to face new challenges. The analysis found that 52 per cent in the variation of mental toughness was down to genetics (Personality and Individual Differences, DOI: 10.1016/j.paid.2008.09.009). It also correlated strongly with extroversion. In contrast, being neurotic or anxious indicated a reduced likelihood of possessing mental toughness. “It’s about not letting setbacks destroy you,” says Peter Clough at the University of Hull, UK, who designed the questionnaire. Clough agrees mental toughness is mostly inherited, but says that natural worriers can deal with anxiety by learning to purge negative thoughts. If you’ve got that precious mettle, thank your parents 16 | NewScientist | 1 November 2008 www.newscientist.com
Transcript of Stars' flickers reveal their inner selves
In brief– Research news and discovery
JOEL
SAG
ET/A
FP/G
ETTY
CAN a pendulum swing in space? It might if it is quantum powered, a fact that could be exploited to build tiny timepieces that run off the quantum fluctuations that occur in a vacuum.
Habibollah Ramzi and Mah Abdollahi from the University of Qom, Iran, envisaged a tiny pendulum made with a string of 30 atoms attached to a conducting plate at one end. They calculated
that the Casimir-Polder force – which arises from the exchange of the “virtual” photons that pop in and out of existence in a vacuum – would attract the nanostring towards the plate. Before it touched the plate, however, the forces between its atoms would force it back. The cycle would repeat, causing the nanostring to swing like a pendulum (Physics Letters A, DOI:
10.1016/j.physleta.2008.09.040).Traditional pendulums rely on
gravity to regulate their swing, but gravity varies with position in space. The Casimir-Polder force, however, is the same everywhere. Roberto Onofrio of the University of Padua, Italy, believes this could make a vacuum clock useful on spacecraft. Yet it will be hard to build one, says Thomas Valone of the Integrity Research Institute in Beltsville, Maryland, because the string would probably twist or stretch as well as swing.
Tick, tock goes the nanostring clock
PURPLE tomatoes will certainly jazz up a ratatouille but they could also protect against cancer.
All tomato plants have the genes to produce anthocyanins – purple pigments found in blueberries that mop up cancer-causing free radicals – but they are dormant. To activate them, Eugenio Butelli’s team from the John Innes Centre in Norwich, UK ‚ inserted two genes from the snapdragon flower. The resulting fruit increased the lifespans of mice engineered to have cancer (Nature Biotechnology, DOI: 10.1038/nbt.1506).
Previous attempts to engineer tomatoes with anthocyanins produced low levels in the skin only, says Butelli. His team’s tomatoes have high levels throughout the fruit.
Purple that’s not just skin deep
FLUCTUATIONS in the brightness of distant stars, measured in finer detail than ever before , are offering unexpected insights into what is going on inside them.
A team led by Eric Michel of the Paris Observatory in France used the CoRoT spacecraft to measure subtle variations in the brightness of three stars. The fluctuations, caused by vibrations in the surface of the star, were 25 per cent weaker than expected. This suggests that astronomers need to refine their ideas of how energy is transformed on stellar surfaces, Michel says ( Science, vol 322, p 558 ).
The variations in brightness also provide evidence of stars’ internal structure and age, as changes in the stars’ composition over time should affect how they vibrate. “This marks the start of a new era of space-based asteroseismology,” says Jørgen Christensen-Dalsgaard of the University of Aarhus in Denmark.
Telling twinkles
THE iron will you need to bounce back and win in sport, or pass exams even when the chips are down, may be largely inherited. Tenacious winners – such as cyclist Lance Armstrong (pictured), who recovered from testicular cancer and went on to win the Tour de France seven times – are naturally tough, a new study suggests, and it may be difficult to boost people who are not naturally resilient.
Tony Vernon at the University of Western Ontario in London, Canada, led a questionnaire-based study of 219 pairs of twins which probed the genetic and environmental
contributions of four traits associated with mental toughness: control over life, commitment, confidence and the ability to face new challenges.
The analysis found that 52 per cent in the variation of mental toughness was down to genetics (Personality and Individual Differences, DOI: 10.1016/j.paid.2008.09.009). It also correlated strongly with extroversion. In contrast, being neurotic or anxious indicated a reduced likelihood of possessing mental toughness.
“It’s about not letting setbacks destroy you,” says Peter Clough at the University of Hull, UK, who designed the questionnaire. Clough agrees mental toughness is mostly inherited, but says that natural worriers can deal with anxiety by learning to purge negative thoughts.
If you’ve got that precious mettle, thank your parents
16 | NewScientist | 1 November 2008 www.newscientist.com
