ريتشارد دوكنز's Blog, page 729

Explore the Tunnels Under London With This Awesome Drone Footage

Technology





Photo credit:

One of the many Crossrail project tunnels. BBC News/YouTube

Disused underground tunnels are the stuff of nightmares and horror films. But it’s impossible for the general public to see a tunnel as it’s being built… until now.

Aerial photographer Jon Bontoft, along with the BBC's own transport team, was granted unprecedented access to capture images and videos via aerial photography of the tunnels, which will site the underground sections of London’s imminent Crossrail train network.

Super-Magnetic Stars Forged in High-Energy Blasts

Magnetars certainly know how to make an entrance. A recent study suggests that these highly magnetized stars make their cosmic debut amid the brightest flares of radiation in the universe, called ultralong-duration gamma-ray bursts (GRBs). This discovery ties together some of the most magnetic and energetic phenomena in the cosmos and sheds light on the mysterious origins of ultralong-duration GRBs.

GRBs are blasts of gamma-ray radiation that typically fade after a few seconds, but on rare occasions can last up to a half hour. The majority of these events are “long-duration” GRBs. Whereas normal GRBs are likely formed by the merging of two neutron stars, scientists think that long GRBs are forged in the explosive deaths of massive stars called supernovae, says lead author Jochen Greiner, an astrophysicist at the Max Planck Institute for Extraterrestrial Physics in Germany.

When a massive star explodes, part of its material is ejected into space whereas the rest collapses into a remnant neutron star or black hole. This violent death spawns two jets of material that spew from opposite sides of the remnant at nearly light-speed. An observer looking down the barrel of one of these jets sees a GRB. The light we recognize as the supernova blooms out from the exploded star in all directions and takes longer to rise, explains Andrew Levan, an astrophysicist at the University of Warwick in England who was not involved with this study. As the GRB “afterglow” fades, the supernova becomes visible, producing a small “bump” in the measured radiation levels.

Scientists pinned down the origin of long GRBs over a decade ago, but in recent years a new class of ultralong GRBs has cropped up, with no apparent link to supernovae. Only four of these bursts have been observed—as compared with the few thousand known “normal” long GRBs—and they shine for several hours. “We've been puzzling over these ultralong bursts for awhile now,” Levan says. Some thought exceedingly massive collapsing stars (aptly called “collapsars”) were responsible whereas others proposed that ultralong GRBs were powered by black holes shredding stars.

Now, for the first time, Greiner and his colleagues have established a clear link between the ultralong GRB 111209A and a supernova, SN 2011kl. But this is not just any stellar explosion. Greiner’s team thinks that the supernova SN 2011kl created a magnetar—a tiny neutron star spinning hundreds of times every second with a magnetic field a quadrillion times stronger than Earth’s. Magnetars are the most magnetic objects in the known universe.

Scientists were first alerted to the flare of GRB 111209A by the Swift Gamma-Ray Burst satellite on December 9, 2011. The event persisted for a few hours, all under the vigilant watch of the Konus gamma-ray detector onboard the interplanetary WIND spacecraft. For the 70 days that followed scientists tracked 111209A’s afterglow. But it wasn’t until last June that Greiner’s team realized this burst was the key to understanding the origins of ultralong GRBs. Supernova data collected by another group of scientists using the X-Shooter spectrometer on the Very Large Telescope in Chile had recently become public, showing there was in fact a supernova associated with GRB 111209A.

The supernova, SN 2011kl, was more than three times as bright as the supernovae previously associated with long GRBs, and its spectrum was completely different. SN 2011kl's characteristics required the supernova to get an extra boost of energy from somewhere. Greiner’s team found that only a magnetar, whose rapid rotation and monster magnetic fields constitute a huge reservoir of energy, could create such a bright flare. The scientists suspect that the magnetar forged in the stellar explosion reenergized the material billowing out from the star in all directions, making for an extremely bright supernova. The magnetar’s immense power similarly and generated the extremely long-lasting jets seen as GRB 111209A. Given the supernova’s distance and the speed of light, scientists estimate this magnetar was born about 6.5 billion years ago.

According to Levan, the link between GRB 111209A and SN 2011kl is crucial not only for uncovering the origins of ultralong GRBs, but also understanding how the supernova itself burned so brightly, because SN 2011kl looks similar to a recently discovered class of superluminous supernovae whose energy source still remains a mystery. “So this new result provides something of a unifying view of a diverse range of stellar collapses,” Levan says. “If correct, it means that magnetars might be the driving force between many of the most energetic events in nature.” At the very least, this new research shows that 111209A and its ultralong fellows fit in with the long GRB family after all.

Parents’ Views on Vaccines are Changing

Health and Medicine





Photo credit:

Adam Gregor/Shutterstock

A third of parents now perceive vaccines as more beneficial than they did a year ago, according to a new poll. The multiple outbreaks of measles and whooping cough in the past year may have affected parents, whose views on vaccines are becoming more positive.  

GM Crops that Produce Fish Oil Successfully Grown in the Field

Plants and Animals





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Fish farming off the coast of Italy. Angelo Giampiccolo/Shutterstock

A genetically modified plant that can produce fish oils has been successfully grown in the field for the first time. The primary dietary source of omega-3 oils, thought to offer health benefits, are marine fish. But now, in a drive to make the fish farming industry more sustainable, scientists have managed to engineer plants to produce them too.

Enzyme System Helps Boost Exercise Tolerance

Health and Medicine





Photo credit:

Brian A Jackson/Shutterstock

Exercise is good for the body and mind, reducing stress, boosting physical fitness and even helping to alleviate certain medical problems. But as we get older or experience certain long-term illnesses, our tolerance to exercise often decreases, fostering inactivity and thus associated declines in heart and metabolic health.

America’s Electricity Grid Catches a Wave for the First Time

Environment





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Azura, a machine that converts wave power into electricity. Northwest Energy Innovations.

Hawaii is giving the rest of America a friendly wave. And it's using this wave to generate electricity for the U.S. power grid for the first time. Scientists are currently just testing the waters with one tidal-powered generator, but if all goes swimmingly, then it might not be long until America finds more and more of its power being supplied by the ocean.

Scientists Control Light Wakes For The First Time

Physics





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Artist's rendition of the wake produced by a fast-moving charge in surface plasmons on gold. Daniel Wintz, Patrice Genevet, and Antonio Ambrosio

A wake has been created on a metal surface out of “light-like waves” known as plasmons. In the process, the creators proved that they can control the wake in ways that may allow the production of new types of holograms and focus light with a precision far smaller than a single wavelength.

Would You get Married in a Church Made From Living Trees?

Environment





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The church on Barry Cox's property in Ohaupo, Waikato. Faith is Torment.

Barry Cox is a man with a dream – a dream to create a grand church on his sprawling property in New Zealand. And he did just that.

This verdant church is located in Waikato, New Zealand, and is set among Cox’s 12,000 square meters (1.2 hectares) of luxuriant gardens. If the sun is shining too brightly, there’s also a shady area under a canopy made from a military cargo parachute.

Why are Pandas so Chilled? The Clue is in the Bamboo

Plants and Animals





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Nah I’m staying here, have already walked 20 metres today. Fuwen Wei, Author provided

It has long been a mystery how giant pandas, which have a gut ideal for digesting meat, can survive eating almost exclusively bamboo. Now our research has found that they can cope with this low-quality diet because they have an extremely slow metabolic rate. This may also explain why they are so inactive and have comparatively small organs for their body size.

Hoops and Hurdles

You can now buy GMO-free Water in the U.S.A

Chemistry





Photo credit:

Alison Cheevers/Genetic Literary Project

Nope, you read that correctly. This water apparently is gluten-free, free of genetically modified organisms (GMO) and free of Bisphenol A (BPA), which is a compound found in the manufacture of some plastics.

Don’t panic though – bottled water that doesn’t explicitly state that it’s free of these suspect substances is still perfectly alright for you.

You can’t tell from the packaging but this water is unusual in one respect – it’s black.