Cyber-attacks in the Baltic raise difficult questions about the threat of state-sponsored information warfare.
Black holes are staples of science fiction and many think astronomers have observed them indirectly. But according to a physicist at the Lawrence Livermore National Laboratory in California, these awesome breaches in space-time do not and indeed cannot exist.
Phillip Ball questions technology guru Ray Kurzweil about his argument that future warfare will be dominated by cyberwarfare and military robots.
Is "synthetic biology" on the point of making life? Unlike genetic engineering or biotechnology, the new discipline is not about tinkering with biology but about remaking it. Risks and rewards will be greater than anything yet encountered.
US researchers have made biologically based solar cells, which convert light into electrical energy, and should be efficient and cheap to manufacture.
The United States is ill prepared to deal with the long term aftermath of a 'dirty-bomb' terrorist attack, say analysts. They warn that existing clean-up laws and regulations covering radioactive materials were not designed with dirty bombs in mind, and give conflicting recommendations.
A new battery harvests electricity from flowing water. One of its creators, Larry Kostiuk, claims that it could make water "an alternative energy source to rival wind and solar power". But its lack of efficiency may stand in the way.
Mankind could lock the world into an irreversible greenhouse effect, banishing future ice ages, warn two Belgian scientists. Global warming caused by emissions of carbon dioxide and other gases could tip the Earth into a completely new climate state in which cycles of freezing and thawing are switched off, they suggest.
Just as the US government has called for a spending review of its neutrino-detection programmes, two teams of scientists raise hopes that these programmes won't be futile after all. Their modelling studies show that if very-high-energy neutrinos are indeed out there, we should be able to see them.
Exploding meteors bombarding the Earth from space could be mistaken for nuclear bomb tests, say seismologists of the Royal Netherlands Meteorological Institute. This could present problems for monitoring the Comprehensive Nuclear Test Ban Treaty (CTBT), which aims to halt the testing of all nuclear weapons.