Science Policy News

To make electricity from sunlight you can convert it directly, using a photovoltaic cell. Or you can use the heat of that sunlight to boil water, and then drive a turbine with the resulting steam. These are both established technologies. But there is, in principle, a third way: use heat directly, without steam or turbines. In this case, unlike a standard solar cell (which is sensitive to some frequencies of light, but not others), almost all of the incident energy is available for conversion. Yet unlike the boiling-water method, no messy mechanical processes are involved.

Scientists finally know the date — and hence the likely cause — of a massive extinction that wiped out 95 per cent of life in the oceans and 70 per cent of life on land more than 200 million years ago. The precise timing coincides with a huge outpouring of carbon dioxide and methane from volcanic lava flows in northwest Asia, as determined by an international team of scientists including Charles Henderson, a geosciences professor at the University of Calgary