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“Solar water” heats Swedish homes
ALEXIS ROSENFELD
Technology VOICEPRINTS FOR DOLPHINS
ELECTRONIC voting has been hit by a fresh blow. An entire ballot may need to be rerun after a software upgrade to touch-screen machines wiped key data. Last Thursday California superior court justice Winifred Smith issued a “tentative” ruling voiding the results of a 2004 vote in Alameda county over restrictions on medical marijuana dispensaries. She called for the measure to appear on the ballot in the county’s next general election. “This case could set a precedent,” says e-voting expert Avi Rubin of Johns Hopkins University in Baltimore, Maryland. The measure initially lost by just 191 votes, prompting a recount. Before the recount got the go-ahead, however, officials returned the machines to their manufacturer, who reset them, destroying 96 per cent of the data.
25 years ago a US teenager created the first computer virus. “Elk Cloner” infected Apple II computers and spread via floppy discs
–They’d know that whistle anywhere–
Solar heat in the depths of winter
SOURCE: SCIENCE, VOL 317, P 210
Deleted data voids e-vote
time, Oswald and her colleagues have turned to acoustics. Dolphins make a range of sounds, including different types of clicks and species-specific whistles. Most whistles are made up of frequencies between 2 and 30 kilohertz, with each species combining the frequencies in its own way. To exploit this, the researchers trail underwater microphones from a survey boat and feed the sound they pick up to an on-board computer. Software then compares the whistle frequencies from the microphones with samples in a database and works out which species made them. In tests, the software identified up to eight species of dolphins near a survey boat with up to 80 per cent accuracy (Journal of the Acoustical Society of America, vol 122, p 587).
By the time 20 per cent of China’s population is online, it will have more users than the US CHINA 137 million users (2007)
10% of population
RELYING on solar heating might sound like a bad idea if you live in a country that sees little daylight for much of the winter. Yet that’s exactly what 50 households in Anneburg, Sweden, have been doing for the past two years. During the summer, water is pumped through rooftop solar heaters to warm it, before being stored in pipes embedded in
granite 65 metres below ground. The water is kept hot by the rock, and can then be pumped back up to heat homes in winter. So far the system has reduced reliance on conventional heating by nearly 25 per cent. This could rise to 70 per cent over the next few years as the storage rocks get hotter, according to an evaluation by a team at Uppsala University. “During the winter season there isn’t that much sun, but we can still use solar,” says team member Magdalena Lundh.
GIZMO
CHINA IS CATCHING UP
US 180 million users (2007)
71% of population
SOURCE: PEW INTERNET & AMERICAN LIFE PROJECT
Is that a bottlenose I hear? Software that identifies different dolphin species by their whistles could improve the accuracy of surveys that monitor possible harm from fishing fleets. These surveys are now performed by observing the animals from a boat. A fall in the number of sightings of a particular species is taken as a warning that it’s time to check what the fishermen are up to. But visual surveys pose problems, says Julie Oswald of the Scripps Institution of Oceanography in San Diego, California. “Marine mammals spend most of their time out of sight and underwater, so observer teams can miss a lot of the animals,” she says. To make matters worse, some species are shy of boats, she adds. To pick up the hidden dolphins, and make identification easier at the same
Forget bricks and mortar. Researchers from the Massachusetts Institute of Technology are making a building out of water. Although it has a solid roof, the Digital Water Pavilion at Expo Zaragoza 2008 in Spain will use 6000 valves spurting water to make “walls” that expand as people fill a room and shrink as they leave. It will not have traditional doors: instead, it will use sensors to part the waters as people approach. Pandas should prepare themselves for competition for their favourite food. Researchers at the PSG College of Technology in Coimbatore, India, have manufactured surgical gowns from bamboo fibre to cut the risk of bacterial infection during surgery. Bamboo contains a natural bactericide. The porous structure of the fibre makes it highly absorbent, and it retains its antibacterial properties even after repeated washing.
“I want Europe to be capable of ensuring its security autonomously” French president Nicholas Sarkozy pushes for a united European military force in a Bastille Day speech to European defence ministers and French military representatives. For the first time, France’s Bastille Day celebrations included troops from all 27 European Union nations (Associated Press, 15 July)
www.newscientist.com
21 July 2007 | NewScientist | 25
Technology VOICEPRINTS FOR DOLPHINS
ELECTRONIC voting has been hit by a fresh blow. An entire ballot may need to be rerun after a software upgrade to touch-screen machines wiped key data. Last Thursday California superior court justice Winifred Smith issued a “tentative” ruling voiding the results of a 2004 vote in Alameda county over restrictions on medical marijuana dispensaries. She called for the measure to appear on the ballot in the county’s next general election. “This case could set a precedent,” says e-voting expert Avi Rubin of Johns Hopkins University in Baltimore, Maryland. The measure initially lost by just 191 votes, prompting a recount. Before the recount got the go-ahead, however, officials returned the machines to their manufacturer, who reset them, destroying 96 per cent of the data.
25 years ago a US teenager created the first computer virus. “Elk Cloner” infected Apple II computers and spread via floppy discs
–They’d know that whistle anywhere–
Solar heat in the depths of winter
SOURCE: SCIENCE, VOL 317, P 210
Deleted data voids e-vote
time, Oswald and her colleagues have turned to acoustics. Dolphins make a range of sounds, including different types of clicks and species-specific whistles. Most whistles are made up of frequencies between 2 and 30 kilohertz, with each species combining the frequencies in its own way. To exploit this, the researchers trail underwater microphones from a survey boat and feed the sound they pick up to an on-board computer. Software then compares the whistle frequencies from the microphones with samples in a database and works out which species made them. In tests, the software identified up to eight species of dolphins near a survey boat with up to 80 per cent accuracy (Journal of the Acoustical Society of America, vol 122, p 587).
By the time 20 per cent of China’s population is online, it will have more users than the US CHINA 137 million users (2007)
10% of population
RELYING on solar heating might sound like a bad idea if you live in a country that sees little daylight for much of the winter. Yet that’s exactly what 50 households in Anneburg, Sweden, have been doing for the past two years. During the summer, water is pumped through rooftop solar heaters to warm it, before being stored in pipes embedded in
granite 65 metres below ground. The water is kept hot by the rock, and can then be pumped back up to heat homes in winter. So far the system has reduced reliance on conventional heating by nearly 25 per cent. This could rise to 70 per cent over the next few years as the storage rocks get hotter, according to an evaluation by a team at Uppsala University. “During the winter season there isn’t that much sun, but we can still use solar,” says team member Magdalena Lundh.
GIZMO
CHINA IS CATCHING UP
US 180 million users (2007)
71% of population
SOURCE: PEW INTERNET & AMERICAN LIFE PROJECT
Is that a bottlenose I hear? Software that identifies different dolphin species by their whistles could improve the accuracy of surveys that monitor possible harm from fishing fleets. These surveys are now performed by observing the animals from a boat. A fall in the number of sightings of a particular species is taken as a warning that it’s time to check what the fishermen are up to. But visual surveys pose problems, says Julie Oswald of the Scripps Institution of Oceanography in San Diego, California. “Marine mammals spend most of their time out of sight and underwater, so observer teams can miss a lot of the animals,” she says. To make matters worse, some species are shy of boats, she adds. To pick up the hidden dolphins, and make identification easier at the same
Forget bricks and mortar. Researchers from the Massachusetts Institute of Technology are making a building out of water. Although it has a solid roof, the Digital Water Pavilion at Expo Zaragoza 2008 in Spain will use 6000 valves spurting water to make “walls” that expand as people fill a room and shrink as they leave. It will not have traditional doors: instead, it will use sensors to part the waters as people approach. Pandas should prepare themselves for competition for their favourite food. Researchers at the PSG College of Technology in Coimbatore, India, have manufactured surgical gowns from bamboo fibre to cut the risk of bacterial infection during surgery. Bamboo contains a natural bactericide. The porous structure of the fibre makes it highly absorbent, and it retains its antibacterial properties even after repeated washing.
“I want Europe to be capable of ensuring its security autonomously” French president Nicholas Sarkozy pushes for a united European military force in a Bastille Day speech to European defence ministers and French military representatives. For the first time, France’s Bastille Day celebrations included troops from all 27 European Union nations (Associated Press, 15 July)
www.newscientist.com
21 July 2007 | NewScientist | 25