Solar cells move outside

New Worlds Outside the Solar System

The discoveries of the first planets around a pulsar and around a star similar to our Sun have opened, after centuries of speculation, a new era in astronomy. The quest for other worlds has become reality. In this paper, the motivations for this search are presented. A comparative review is made of different techniques for their detection, with special attention paid to the planet parameters th...

Backward waves move cells forward

dvancing cells periodically pull on their substrates to test the environment, say Grégory Giannone, Michael Sheetz (Columbia University, New York, NY), and colleagues. The actomyosin contractions both strengthen attachments to more solid substrates, and break off part of a signaling complex so that it can be carried into the cell. Once that retrograde signal reaches myosin, which is some distan...

Interiors of giant planets inside and outside the solar system.

An understanding of the structure and composition of the giant planets is rapidly evolving because of (i) high-pressure experiments with the ability to study metallic hydrogen and define the properties of its equation of state and (ii) spectroscopic and in situ measurements made by telescopes and satellites that allow an accurate determination of the chemical composition of the deep atmospheres...

The Search for Life outside the Solar System

Atp inside Cells . . . and Outside

KE N E W A RD One of the fi rst and most enduring facts most students learn in biology class is that all living cells use a small molecule called adenosine triphosphate (ATP) as fuel. That universal energy currency drives the biological reactions that allow cells to function and life to fl ourish—making ATP a crucial player in the biological world. Less commonly known, however, is that what is ...