Cornell University researchers in New York revealed that they had produced what is believed to be the world's first genetically altered human embryo--an ironic twist considering all the criticism the US has heaped on South Korea over the past several years for going "too far" with its genetic research programs. The Cornell team, led by Nikica Zaninovic, used a virus to add a green fluorescent protein gene, to a human embryo left over from an in vitro fertilization procedure. The research was presented at a meeting of the American Society of Reproductive Medicine last year, but details have emerged only after new controversy has emerged over the ethics and science of genetically modifying humans.

Zaninovic has pointed out that in order to be sure that the new gene had been inserted and the embryo had been genetically modified, scientists would ideally want to keep growing the embryo and carry out further tests. However, the Cornell team did not get permission to keep the embryo alive. The GM embryos created could theoretically have become the world's first genetically altered man or woman, but it was destroyed after five days.

Keith Schwab builds bridges. By most people's standards, they are very small bridges indeed: around 8 thousandths of a millimetre long and 200 millionths of a millimetre wide, visible only under a microscope. But to Schwab's eye, these objects are huge. That's because he is hoping to see them behave according to the rules of quantum mechanics -- rules that allow for bizarre, counterintuitive behaviour such as being in two places at once. Quantum mechanics is generally thought to govern objects such as individual atoms, not lumps of matter like these bridges, which contain tens of billions of atoms.

It is an ambitious goal. But Schwab, based at Cornell University in Ithaca, New York, is one of several experimentalists seeking to probe one of the great conundrums of modern physics: the quantum--classical transition. Here, the fuzzy quantum world somehow gives way to the solid, definite certainties of the everyday 'classical' world as we go up the scale from atoms to apples. If these experiments manage to confirm current theories of this transition, they could turn long-standing preconceptions about quantum theory on their head.