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Number 380, July 1, 1998 by Phillip F. Schewe and Ben Stein
ACOUSTIC SURGERY is the use of sound in place of the scalpel to perform such tasks as destroying tumors and stopping internal bleeding. At last week's joint meeting in Seattle of the International Congress on Acoustics and the Acoustical Society of America, Gail ter Haar of the Royal Marsden Hospital in England (011-44-181-642-6011) described a clinical trial in which focused sound waves destroyed parts of liver, kidney, and prostate tumors in 23 patients. Just as sunlight sent through a magnifying glass can burn a leaf placed at the spot where the light converges, sound broadcast through a specially shaped set of speakers can converge inside the body to create a region of intense heat that can destroy tumor cells. The spot is so small that there is only a boundary of six cells between destroyed tissue and completely unharmed tissue--a precision that is finer than any scalpel. Ter Haar said the next phase is to attempt complete destruction of tumors in the liver and prostate. (See www.acoustics.org/haar.htm) Meanwhile, Roy Martin of the University of Washington (206- 685-1883) discussed the use of ultrasound to stop internal bleeding in the liver. Just as a grill heats a steak, the sound waves heat the bleeding area to create chemical and physical changes that cauterize it. Otherwise, liver surgery is often hampered by bleeding, Martin said.
A NEW FORM OF SOLID CARBON, based on carbon-36 molecules, has been created by Alex Zettl and his colleagues at LBL. The new Bucky-lite materials---liquids, powders, and films---were extracted from the general stew of fullerenes created in an electrical arc flashing between two graphite electrodes. The C-36 molecule is under more strain than the better- known C-60 molecule and this, the researchers believe, should lead to interesting electrical and chemical properties. C-36 solids, spiked with alkali metals, might be superconducting at temperatures as high as for ceramic superconductors. (Nature, 25 June 1998.)
SUPERFLUIDITY WITH ONLY 60 ATOMS has been demonstrated by scientists at the Max Planck Institute in Gottingen. They dissolved molecules of oxygen carbon sulphide (OCS) into a mixture of He-3 and He-4 atoms held at a temperature below the superfluid point of He- 4 but above that for He-3. From the infrared spectrum emitted by the OCS, the researchers deduce that the molecule is rotating freely inside a cocoon of superfluid He-4 atoms only about 2 layers thick, which in turn resides within a He-3 droplet. In effect, the He-4 acts as a vacuum in which the OCS turns without friction. (Science, 27 March.)
EXEBYTES OF INFORMATION. Essayist and scientist Philip Morrison ponders the magnitude of recorded information. The ancient library at Alexandria contained about 600,000 scrolls, the equivalent, Morrison estimates, of about 50,000 books. The Library of Congress now holds about 20 million books containing (at roughly a million bytes per book) about 20 terabytes of information. Add to this several petabytes (million billion bytes) in the form of sound recordings. New books and newspapers worldwide account for a bit less than 100 terabytes each year. A century's worth of movies add a petabyte to the accumulation and home pictures (all the snapshots ever taken) another 10 petabytes. According to Morrison, the brightest sources in the information universe are television (100 petabytes per year) and telephony (several thousand petabytes, or exebytes, of audio data annually). Very roughly 100 petabytes of information (mostly TV) are recorded in a form that can (or will) be retrievable. (Scientific American, July 1998.)
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