Physics and Astronomy

When comet Tempel 1 collides with a NASA space probe in the early morning hours of July 4, 2005, scientists at the Jet Propulsion Laboratory expect some holiday sizzle – a brilliant flash and a dramatic spray of debris.

This cosmic collision will create a crater exposing Tempel 1’s interior. Like all comets, Tempel 1 consists of the frozen remains of material that formed the solar system. But what, precisely, is this stuff? How is it put together? Peter Schultz, crater expert, wil

Science fiction writer Harlan Ellison once said that the most common elements in the universe are hydrogen and stupidity.
While the verdict is still out on the volume of stupidity, scientists have long known that hydrogen is indeed by far the most abundant element in the universe. When they peer through their telescopes, they see hydrogen in the vast clouds of dust and gas between stars –- especially in the denser regions that are collapsing to form new stars and planets.

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Ohio State University physicists have obtained the first-ever experimental evidence of a particular quantum mechanical effect –- one that was theorized a decade ago.

The effect, called quantum monodromy (Greek for “once around”), relates in part to the behavior of molecules based on their atomic structure and vibrational frequencies. A better understanding of quantum monodromy could have implications in astronomy, atmospheric science, and biology.

The physicists reported t

Unsurpassed exciton distances, lifetimes may lead to new form of optical communication

When light hits a semiconductor material and is absorbed, its photons can become “excitons,” sometimes referred to as “heavy photons” because they carry energy, like photons, but have mass, like electrons. Excitons typically exist for only a short time–trillionths of a second–and travel only a few microns before turning back into photons, which are then emitted from the material.

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ESA’s comet chaser Rosetta will take part in the one of world’s largest astronomical observation campaigns – the Deep Impact event – while on its cruise to Comet 69P/Churyumov-Gerasimenko. Rosetta will be watching from 29 June to 14 July 2005.

Deep Impact is a NASA mission to send a 370 kg copper ‘impactor’ probe to Comet 9P/Tempel 1 on 4 July 2005. Tempel 1 is a short-period comet, whose orbit runs between those of Mars and Jupiter. There is scientific interest in comets because th

Engineers have introduced a new magnetic shepherding approach for deftly moving or positioning the kinds of tiny floating objects found within organisms, in order to advance potential applications in fields ranging from medicine to nanotechnology.

The authors of a new research article said their method avoids pitfalls of using tiny light beams, electric currents or even a competing magnetic approach to micromanipulate so-called “colloidal” objects. “Biology is composed prima