Clues to the Sherman Tanks of the Seashore
Seashell collectors admire them for their beauty and intricate design. Scientists have another point of view. They have long sought to explain how clams, snails and other mollusks control their shell-building process, arranging minerals with remarkable precision to produce a strong covering.
Weizmann Institute researchers, in a recent issue of Science magazine, report having found a major piece of the puzzle, one that could lead to new ideas for designing improved composite materials such as those used in aircraft parts, orthopedic prostheses and a variety of other devices.
Mollusk shells are made of a natural composite material that consists of a supporting protein framework filled with calcium carbonate crystals. These crystals come in two types: One often forms the rougher outer layer of the shell, and the other--commonly known as mother-of-pearl--has a slightly different structure with different properties. Having the right kind of crystal growing in the right place is crucial to the strength of the shell.
The researchers have shown that what mollusks do to control the formation of the appropriate type is to manufacture two different support proteins, each specializing in a different crystal type. These proteins then go on to regulate the entire process of determining which type of crystal goes where. By studying the structure of these protein molecules, they hope they can provide materials researchers with ways to mimic the mollusks’ engineering.
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Mightier Than the Mouse: Pen computing has been scorned because too often the computer can’t read someone’s handwriting. And nobody has yet come up with pen computing software that would induce people to switch from keyboard and mouse.
However, IBM believes people need to think of the pen not as a writing tool but as a natural means of communicating across networks. If the pen can be combined with other technologies, it could have a far greater effect.
A team at Thomas J. Watson Research Center has a prototype application for the car rental business. Using it, you could rent a car at a kiosk rather than a rental counter. You and the rental agent at a remote location would have pens, large screens and video cameras to provide visual contact. You would see short videos of the cars available. Then you and the agent would go through the process of filling out a rental contract electronically, signaling items of concern to each other with your pens. After you signed the form electronically, you would get a printout of the contract.
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Shifting Sands: Sand may look stable, but it is constantly moving--as anyone who has lived near the ocean knows. That fact is of particular interest to beach communities, whose fortunes can depend on sand’s behavior.
A team of geologists at UC Santa Cruz, led by coastal geology expert Gary Griggs, are attempting to study sand movement. They have discovered that sand grains travel along certain routes. Using gear such as computers, sonar and mathematical tools borrowed from seismology, researchers have found that sand in Monterey Bay comes from the north, perhaps from the sand shoals in San Francisco Bay.
Griggs estimates about 300,000 cubic yards pass by every year. Information about the natural movement of sediment also helps geologists understand the balance between erosion and beach formation. This balance was upset last year in Santa Cruz when a lovely beach suddenly appeared after a big storm in January, only to disappear eight months later.
