| January, 2008 |  |
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NASA Breaking News
International Group Plans Strategy for Mars Sample Return Mission
NASA and an international team are developing plans and seeking recommendations to launch the first Mars mission to bring soil samples back to Earth.
NASA Deputy Administrator Visits Central America
On Wednesday, Dec. 12, NASA's Deputy Administrator Shana Dale will join NASA researchers to brief reporters about the agency's Earth sciences activities in Central America and their benefits to the region.
NASA Announces Discovery of Assault by a Black Hole
Astronomers will hold a media teleconference Monday, Dec. 17, at 1 pm EST to announce the discovery of a first-of-its-kind phenomenon involving a black hole and a neighboring galaxy.
NASA Targets Space Shuttle Atlantis Launch on Jan. 2
Space shuttle Atlantis' STS-122 mission to the ISS now is targeted to launch no earlier than Jan. 2 from NASA's Kennedy Space Center.
[Thanks, AMSAT]
‘Stealth’ antenna made of gas is impervious to jamming
A new antenna made of plasma (a gas heated to the point that the electrons are ripped free of atoms and molecules) works just like conventional metal antennas, except that it vanishes when you turn it off.
That’s important on the battlefield and in other applications where antennas need to be kept out of sight. In addition, unlike metal antennas, the electrical characteristics of a plasma antenna can be rapidly adjusted to counteract signal jamming attempts.
Plasma antennas behave much like solid metal antennas because electrons flow freely in the hot gas, just as they do in metal conductors. But plasmas only exist when the gasses they’re made of are very hot. The moment the energy source heating a plasma antenna is shut off, the plasma turns back into a plain old (non conductive) gas.
As far as radio signals and antenna detectors go, the antenna effectively disappears when the plasma cools down.
You can read more on this at the Scientific Blogging website
MIT researchers use light to move tiny particles
Taking up the sci-fi staple of “tractor beams,” scientists have developed a way to use light to grab and move minuscule particles on a microchip. The research could lead to fine-grained biological sensors and other precisely built nanoscale devices.
The work by Massachusetts Institute of Technology researchers could extend the possibilities for “optical tweezers” — super-focused beams of light that have been used for years to study and manipulate tiny biological structures or even individual atoms.
Optical tweezers have been used on transparent media — like a microscope slide — that let the light shine through and hold objects in a tractor beam-like embrace. This is possible because light’s individual photons transfer minuscule amounts of force to particles they hit.
What’s new in the optical tweezer from MIT’s Matt Lang and David Appleyard is that they used infrared light to move particles on silicon, the basis of microchips. (Unlike visible light, the infrared does not bounce off the silicon.) That means that MIT’s optical tweezer can be used not just for study but to build structures on the surface of chips.
Lang and Appleyard proved their technique by getting 16 live E. coli cells to spell out “MIT” on a chip. The long-term potential is more practical: Lang envisions using the system to cram high-resolution sensors in very small spaces — for disease detectors, for example — and to connect silicon-based electronics to living tissues and other “biological interfaces.”
“That’s sort of wide open,” said Lang, a professor of biological engineering and mechanical engineering. The research is being published in an academic journal, Lab on a Chip.
Arthur Ashkin, a retired Bell Laboratories scientist who is considered the father of optical tweezers, cautioned that the MIT work could not be considered a breakthrough, since no devices using the technology have yet been built.
| January, 2008 | |
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