Thursday, December 10, 2009
Wednesday, December 9, 2009
Physicist Proposes New Method for Quantum Propulsion
According to quantum mechanics, any vacuum will be filled with electromagnetic waves leaping in and out of existence. This approach exploits aspects of quantum vacuum to create propulsive force. Article is on MIT's Technology Review.
Monday, December 7, 2009
Single-Atom Transistor Discovered
Science Daily reports that a research team has succeeded in building a working transistor "whose active region composes only of a single phosphorus atom in silicon". This research is working towards enabling quantum computing, with the idea of utilizing the spin degree of freedom of an electron of the phosphorus donor as a quantum bit, a qubit.
The researchers were able to observe in their experiments spin up and down states for a single phosphorus donor for the first time. This is a crucial step towards the control of these states, that is, the realization of a qubit.
A particularly interesting thought mentioned in the story that isn't heard often outside of the scientific community is that "the rapid development of computers, which created the present information society, has been mainly based on the reduction of the size of transistors." In other words, much of our way of life in the 21st century is substantially due to the historical and ongoing miniaturization of transistors.
The researchers were able to observe in their experiments spin up and down states for a single phosphorus donor for the first time. This is a crucial step towards the control of these states, that is, the realization of a qubit.
A particularly interesting thought mentioned in the story that isn't heard often outside of the scientific community is that "the rapid development of computers, which created the present information society, has been mainly based on the reduction of the size of transistors." In other words, much of our way of life in the 21st century is substantially due to the historical and ongoing miniaturization of transistors.
Usability defined
I ran across a very good definition of usability from Jakob Nielsen:
"a quality attribute that assesses how easy user interfaces are to use. The word 'usability' also refers to methods for improving ease-of-use during the design process." He defines five quality components of usability:
• Learnability: How easy is it for users to accomplish basic tasks the first time they encounter the design?
• Efficiency: Once users have learned the design, how quickly can they perform tasks?
• Memorability: When users return to the design after a period of not using it, how easily can they reestablish proficiency?
• Errors: How many errors do users make, how severe are these errors, and how easily can they recover from the errors?
• Satisfaction: How pleasant is it to use the design?"
"a quality attribute that assesses how easy user interfaces are to use. The word 'usability' also refers to methods for improving ease-of-use during the design process." He defines five quality components of usability:
• Learnability: How easy is it for users to accomplish basic tasks the first time they encounter the design?
• Efficiency: Once users have learned the design, how quickly can they perform tasks?
• Memorability: When users return to the design after a period of not using it, how easily can they reestablish proficiency?
• Errors: How many errors do users make, how severe are these errors, and how easily can they recover from the errors?
• Satisfaction: How pleasant is it to use the design?"
Friday, December 4, 2009
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