Gone today, hair tomorrow

PEOPLE’S ability to hear depends on bundles of tiny hairs found inside their ears. When these bundles vibrate in response to sound, cells at their base send signals to the brain, which then translates them into the rich symphony that fills the world. In normal circumstances, this symphony leaves the hairs unharmed. But exceptionally loud noises—close cracks of thunder, the emissions of rock-concert loudspeakers and so on—can disorganise the bundles, traumatising and sometimes killing the cells they are connected to. Doctors have long believed such damage to be irreversible, but an experiment led by Glen Watson of the University of Louisiana, Lafayette, and published in the Journal of Experimental Biology, suggests an ointment containing proteins harvested from sea anemones may do the trick.

Some anemones, such as Nematostella vectensis, pictured above, have a primitive sense of hearing: tiny hair bundles scattered along their tentacles sense when animals that they can sting are nearby. Wounds from battles with struggling prey often disorganise these bundles but, unlike the hair bundles found in the ears…Continue reading
Source: Economist

Flight fantastic

THE idea of a drone—an aircraft designed from scratch to be pilotless—is now familiar. But what if you want to make pilotless a plane you already possess? Air forces, particularly America’s, sometimes do this with obsolete craft that they wish to fly for target practice. By using servomotors to work the joystick and the control surfaces, and adding new instruments and communications so the whole thing can be flown remotely, a good enough lash-up can be achieved to keep the target airborne until it meets its fiery fate. The desire for pilotlessness, though, now goes way beyond the ability to take pot shots at redundant F-16s. America’s air force wants, as far as possible, to robotise cargo, refuelling and reconnaissance missions, leaving the manned stuff mostly to its top-gun fighter pilots. This could be done eventually with new, purpose-built aircraft. But things would happen much faster if existing machines could instantly and efficiently be retrofitted to make their pilots redundant. 

Shim Hyunchul and his colleagues at KAIST (formerly the Korea Advanced Institute of Science and Technology) think they can manage just that. They plan to do…Continue reading
Source: Economist

Now try this

IF HUMAN beings could have conversations with animals, many a conservationist would bring up the subject of invasive plants. “Try this one,” they would plead with their fauna. “It’s new, it may take some getting used to, but it’s nutritious. And it really, really needs a natural enemy around here.”

Such a meeting of minds has taken place, after a fashion, in Hungary. The animals in question are rabbits. A group of biologists led by Vilmos Altbäcker of Kaposvar University have persuaded these lagomorphs to add common milkweed to their diet.

Milkweeds are native to North America, and famous there as host of the caterpillars of the monarch butterfly. Elsewhere, though, they can be pests, for they are poisonous to many grazing animals, notably cattle, sheep and horses. But not to rabbits, at least not the common milkweed, Asclepias syriaca, that has been overwhelming Kiskunsag National Park in Hungary. When confined to cages, and offered little other food, rabbits will eat it and thrive.

That is a far cry from persuading wild rabbits of milkweed’s virtues. But Dr Altbäcker thought this could be…Continue reading
Source: Economist

The brain that stopped remembering

Source: Economist

The 2016 Perseid meteor shower in pictures

The spectacular annual Perseid meteor shower peaked overnight on August 11th. It was a bumper year, with some 200 meteors lighting up the sky every hour when the shower was at its most active.

The Perseids are seen as Earth passes through a trail of dust and debris left behind by the comet Swift-Tuttle. They are so named because they appear to radiate from the constellation of Perseus, the rescuer, in Greek mythology, of Andromeda (whose constellation is a little to the west of Perseus) who was in turn the daughter of Cassiopeia (a little to the north).

The dust particles hit the Earth’s atmosphere at more than 200,000kmph and vaporise at an altitude of about 100km, giving the appearance of bright streaks of light zipping across the sky, with the larger fragments creating fireballs that sometimes explode.

This year’s display peaked early, and that peak was more spectacular than the normal one of 60-100 an hour; the gravitational pull of Jupiter tugged together a number of meteor streams so that the Earth passed through them…Continue reading
Source: Economist

Controlled fire storms could be a greener way to clean up marine oil spills

FIRE whirls, also known as fire tornadoes and even fire devils, sound like something out of a medieval vision of hell. In fact, they are natural phenomena caused by hot air rising in a column during a large fire, such as a forest fire, and then swirling into a vortex as much as 30 metres high. Inside this vortex, wind speeds can reach 250km an hour and the temperature may rise beyond 1,000ºC.

Fire whirls are sometimes started deliberately by researchers trying to discover how to extinguish them. But Michael Gollner of the University of Maryland and his colleagues have a different approach. They wonder if these elemental demons might be tamed and used for good—specifically, for clearing up oil spills at sea. Their research, just published in the Proceedings of the National Academy of Sciences, suggests the answer might be “yes”.    

In the right conditions, it is possible to create small fire whirls in a laboratory, which Dr Gollner’s team did. The fuel for their whirls was heptane, a light, liquid hydrocarbon that is often part of accidental oil spills. Their whirl-generating chamber had, at its base, a pool…Continue reading
Source: Economist

At last, the 48 show

VOLTAGE is to electricity what pressure is to water: the more you have of it the more oomph you get. That is why electrical power lines work at high voltage. In the 1950s carmakers needed extra oomph of this sort to start the powerful high-compression engines then being introduced, so they increased the voltage of their vehicles’ electrical systems from six to 12. Now voltages are going up again—to 48.

One reason is that cars are packed with more and more components, demanding more and more electrical power. A modern vehicle may have as many as 150 electric motors. But there is a second reason for the increase, too. Extra voltage lets engineers design cars in novel ways that boost engine output and efficiency. This can be used to make hybrids on the cheap (some people call them “mild hybrids”). These employ a combination of electric motors and combustion engines to cut both fuel consumption and polluting emissions.

The first production car to use 48 volts is the SQ7, a new luxury sports-utility vehicle made by Audi, a German firm that is part of the Volkswagen Group. It is not a hybrid, but it employs an electrically driven 48-volt…Continue reading
Source: Economist

No hard feelings

What’s a grand-slam championship between friends?

MEN have a long history of fighting with one another for dominance, but why such duels did not leave tribal unity in tatters and warriors less capable of working together to fend off attacks from predators and hostile clans remains a mystery. One common theory is that men more readily make up after fierce physical conflicts than do women. And an experiment run recently at Harvard University, by Joyce Benenson and Richard Wrangham, and published in Current Biology, suggests this may be true.

Tribal contests like Yanamamo clubbing duels, in which men take turns bashing each other on the head until one surrenders or is knocked out, were not regarded as suitable for the Harvard campus. The researchers speculated, however, that less lethal competitive sports could stand in for such pursuits, given that they are standardised, aggressive and intense confrontations which take place in front of an audience.

To this end, they collected 92 videos of male championship tournaments in tennis, table tennis, badminton and boxing, and 88 videos of female…Continue reading
Source: Economist

Bee kind to viruses

The smell of sickly sweetness

CUCUMBER mosaic virus is not restricted to its eponymous host. It can also ravage tomatoes—stunting them and causing them to produce contorted tendril-like leaves. Given this devastation, it is surprising susceptible plants continue to exist; natural selection should have produced resistance years ago. A paper in this week’s PLoS Pathogens, however, explains the apparent contradiction. The team that wrote it, led by John Carr of Cambridge University, found that the virus actually helps its host to reproduce. It does so using an unsuspecting accomplice: the bumble-bee.

Like many discoveries, this one was accidental. Dr Carr had ordered some equipment to analyse the volatile chemicals emitted by infected tomato plants. While he was waiting for it to arrive, a colleague offered to lend him some bees, as these pollinators are known for their sense of smell. His team placed both healthy and infected plants in a greenhouse, covered them so that the bees could smell but not see them, and released the insects.

The bees could indeed tell…Continue reading
Source: Economist

The evolution of bromance

Source: Economist