A device capable of counting the individual electrons in an electric current, by feeding them through a pair of quantum dots, has been developed by scientists in Japan. The device can even spot the "backscattering" that occurs when electrons travel the wrong way through a circuit.
Toshima Fujisawa and colleagues at NTT Basic Research Laboratories in Atsugi, Japan, created a circuit incorporating a two quantum dots - semiconducting crystals just a few nanometres in diameter - which only let a single electron pass through at a time. After switching the current on, they used another nanoscale device, called a quantum point contact, to measure the charge contained within each quantum dot. This revealed whether it contained an electron or not.
By taking measurements every 20 microseconds the researchers could count the flow of individual electrons as they passed through the quantum dots, and also determine the direction in which they were moving. Link
Sunday, June 18, 2006
Saturday, June 17, 2006
Vampire Bats Recognize Prey’s Breathing
Vampire bats, the only mammals to feed exclusively on blood, including human blood, recognize their prey by the sound of its breathing. In a new study vampire bats of the species Desmodus rotondus could recognise recorded human breathing sounds much better than human participants could. Vampire bats feed on the same prey over several nights and the authors of the study propose that the bats use breathing sounds to identify their prey in the same way as humans use voice to recognise each other.
In a study two vampire bats were taught to associate recordings of different humans breathing with different cattle blood dispensers, providing food rewards. They were then played short clips of people breathing and had to associate them with the correct individual by going to the correct dispenser. Four human participants were asked to associate the same short clips with the correct individual.
The vampire bats were able to spontaneously associate the clips with the particular individuals, regardless of whether the individual was recorded breathing at rest or breathing while under physical strain. The human participants were also able to recognise some clips, but they were unable to recognise the clips of breathing recorded under physical strain.
Ref: Classification of human breathing sounds by the common vampire bat, Desmodus rotundus. 2006. L. Wiegrebe and U. Groeger. BMC Biology 2006 4: 18
In a study two vampire bats were taught to associate recordings of different humans breathing with different cattle blood dispensers, providing food rewards. They were then played short clips of people breathing and had to associate them with the correct individual by going to the correct dispenser. Four human participants were asked to associate the same short clips with the correct individual.
The vampire bats were able to spontaneously associate the clips with the particular individuals, regardless of whether the individual was recorded breathing at rest or breathing while under physical strain. The human participants were also able to recognise some clips, but they were unable to recognise the clips of breathing recorded under physical strain.
Ref: Classification of human breathing sounds by the common vampire bat, Desmodus rotundus. 2006. L. Wiegrebe and U. Groeger. BMC Biology 2006 4: 18
Abbott & Costello Meet Bela Lugosi
Heat Vision and Jack
Watch the first and only episode:
Friday, June 16, 2006
Arctic Scientists Investigate Alien-Like Glacier
Unusual sulfur springs on Ellesmere Island suggests how live may evolve on other planets
A scientific expedition to a remote glacier field in Canada's High Arctic may help researchers unlock the secrets about the beginning of life and provide insights for future exploration of our solar system.Scientists will study a sulfur-spewing spring on the surface of an ice field not far from the North Pole this summer. The geological oddity is home to a unique form of bacteria that has adapted to thrive in a cold and sulfur-rich environment.
"This is a very unusual feature on the earth's surface and it's an extreme ecosystem that could be a good model for how life first begins in a harsh environment."
The spring has also attracted the attention of the Canadian Space Agency and NASA, which are helping to fund the expedition, because it likely provides the best example on Earth for the conditions believed to exist on the surface of Jupiter's moon Europa. Ice-covered Europa is considered one of the best candidates for finding evidence of life on other planets within our solar system. Link
Pete Von Sholly's 'Space Thing'
The figure is conveniently small (approximately 4 1/2 inches), pre-painted, and easy to pop together with a great-looking, Aurora-inspired display box.
Available now HERE. ISBN: 1-59617-325-4
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