Rice lab mimics Jupiter's Trojan asteroids inside a single atom - YouTube

Rice University physicists have built an accurate model of part of the solar system inside a single atom.

In a new paper in Physical Review Letters, Rice's team and collaborators from Oak Ridge National Laboratory and the Vienna University of Technology showed they could make an electron orbit the atomic nucleus in the same way that Jupiter's Trojan asteroids orbit the sun.

The findings uphold a 1920 prediction by physicist Niels Bohr.

"Bohr predicted that quantum mechanical descriptions of the physical world would, for systems of sufficient size, match the classical descriptions provided by Newtonian mechanics," said lead researcher Barry Dunning, Rice's Sam and Helen Worden Professor of Physics and chair of the Department of Physics and Astronomy.

"Bohr also described the conditions under which this correspondence could be observed. In particular, he said it should be seen in atoms with very high principal quantum numbers, which are exactly what we study in our laboratory."

Bohr was a pioneer of quantum physics. His 1913 atomic model, which is still widely invoked today, postulated a small nucleus surrounded by electrons moving in well-defined orbits and shells.

The word "quantum" in quantum mechanics derives from the fact that these orbits can have only certain well-defined energies.

Jumps between these orbits lead to absorption or emission of specific amounts of energy termed quanta.

As an electron gains energy, its quantum number increases, and it jumps to higher orbits that circle ever farther from the nucleus.

In the new experiments, Rice graduate students Brendan Wyker and Shuzhen Ye began by using an ultraviolet laser to create a Rydberg atom.

Rydberg atoms contain a highly excited electron with a very large quantum number. In the Rice experiments, potassium atoms with quantum numbers between 300 and 600 were studied.

China Embraces GM Strains of Rice and Corn

China has approved genetically modified strains of rice and corn in a move experts say could dramatically boost crop yields and help the world's most populous nation avoid food shortages.

The Ministry of Agriculture said it had issued initial production licences for genetically modified rice and corn, paving the way for commercial cultivation of high-yielding and pest-resistant grain and cereal crops.

In a fax to AFP this week, the ministry said the decision was "an important outcome of China's research on genetic engineering technology".

"It lays a good foundation for commercial production," the ministry said.

Further approvals are required before the genetically modified rice and corn can be grown commercially, it added.

Huang Dejun, chief analyst with Beijing Orient Agribusiness Consultant, said the government wanted the agricultural industry "to be prepared" for a potential grain shortage.

"China's grain security is guaranteed now... but it is hard to rule out the possibility (of a shortage) as living standards improve or yields slump because of a sharp decrease in the area of farming land or serious impacts of climate change," Huang said.

The technology could increase rice and corn yields by about 30 percent, Huang estimated.

Beijing said in July 2008 that it aimed to cultivate high-yielding and pest-resistant genetically modified grains as it faces the challenge of feeding its 1.3 billion people and battles shrinking arable land and climate change.

China is a major producer of genetically modified cotton and vegetables such as peppers and tomatoes.

But Greenpeace China said the commercialisation of genetically modified rice was a "dangerous genetic experiment" and called on Beijing to make public the health and environmental studies used in the certification process.

"Rice is the most important staple food for Chinese people and our babies grow up on rice," said Lorena Luo, Greenpeace China's food and agriculture campaigner.

"People have the right to know whether the rice they eat has any health risk. Who are these... scientists in the committee to make the decision for 1.3 billion people?"

No varieties of genetically modified rice are currently grown commercially in the world although several have been approved, according to the International Rice Research Institute in the Philippines.

China produces about 20 percent of the world's corn and 30 percent of its rice, according to the US Department of Agriculture website.

China's cabinet in July 2008 approved a mid- and long-term grain security plan that aims to keep annual output above 500 million tonnes by 2010 and increase production to more than 540 million tonnes a year by 2020.

Premier Wen Jiabao said at the time that China faces serious challenges in ensuring it will have enough grain to feed its population in the decades to come, citing urbanisation and climate change as two major problems.

But at a conference on world food security in Rome last month, Chinese Vice Premier Hui Liangyu said China now has a "favourable food security situation" with abundant grain reserves and sufficient supply of staple crops, according to the China Daily.