A glass of champagne; a mini ocean

A tiny bubble can do a lot of work. In the ocean, for example, rising air bubbles in the surf drag certain compounds to the surface. These compounds, called surfactants, have a water-loving end (which stays in the water) and a water-avoiding end (which stays inside the bubble); when the bubbles reach the surface and pop, the surfactants are released. The effect is to concentrate these compounds in the air in the vicinity of the surf. A glass of champagne, it turns out, is like a mini ocean. When the cork is popped, bubbles of carbon dioxide form and rise to the surface. A study by European researchers shows that these bubbles concentrate surfactants, many of which contribute to champagne’s odour and flavour, in the air above the beverage. Gerard Liger-Belair of the University of Reims (in the Champagne region of France, naturally), Philippe Schmitt-Kopplin of the German Research Center for Environmental Health and colleagues used extremely high-resolution mass spectrometry to analyse the differences between the Champagne in the glass and in the air just above it.

The researchers note in their paper, in The Proceedings of the National Academy of Sciences, that champagne potentially produces on the order of 100 million bubbles per bottle. Given an average bubble diameter of about one-fiftieth of an inch, that means there is a total of about 100 square yards of surface area separating the bubbles from the bubbly. That is a lot of area to harbour surfactants.

The researchers first used a scattershot approach that revealed potentially hundreds of compounds that were, essentially, being dragged out of the champagne and becoming concentrated in the air above it. More discriminating analysis showed that several dozen of these compounds probably played a role in producing the beverage’s aroma or flavour.
The researchers suggest that champagne bubbles act like an elevator, bringing aromatic compounds up out of the liquid and into the air above it. The effect continues over and over as bubbles continue to form.

Henry Fountain
NYT News Service

Earth’s curvature caught on camera

An American science student has captured images of the curvature of the Earth after sending a balloon into space on a shoestring budget. Oliver Yeh spent less than $150 (£93) on a secondhand camera, a GPS-enabled mobile phone, a weather balloon and a polystyrene coolbox which he launched from a field in Massachusetts as part of a science project.

The result was a time-lapse array of stunning photographs from the edge of space that could easily have come from Nasa, with its $17bn annual budget.

Yeh, a student at Massachusetts Institute of Technology, enlisted two friends to help with Project Icarus, which he dreamed up to prove that it was possible to reach the upper levels of the atmosphere even on a tight budget.

“For me, it was just about not being afraid to do what I love to do,” the 20-year-old said. “Before, people were just kind of, ‘That’s a crazy idea; there he goes all over again.’” The camera, which Yeh bought, was positioned inside the coolbox to protect it from -40C temperatures 17.6 miles above the Earth’s surface. He cut a small hole for the lens, then hooked the camera up to a computer programme that instructed it to take photographs every five seconds. He also placed a phone inside that broadcast its co-ordinates to help the team find and retrieve the device when the helium-filled balloon popped and it returned to Earth on a parachute.

The students launched the balloon on September 2 near their college. They expected the flight to last five hours, but soon lost contact with it, fearing that the low temperatures had frozen the phone’s battery. They later rediscovered the signal and found the camera undamaged 25 miles from the launch area. The team has since collated the hundreds of photographs taken during the flight into a video that they posted on YouTube and on their own website. Yeh says his favourite image is the one taken at the peak of the flight, 17.5 miles from the Earth’s surface, just as the camera began its descent.

Richard Luscombe
The Guardian

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