Johns Hopkins Magazine -- September 1997
Johns Hopkins Magazine


S C I E N C E    &    T E C H N O L O G Y

Smoothing news for those with shaky handwriting... the young and the old collide in space... lessons from Silicon Valley... mighty Mathilde

Top: Tremor prevents a patient from drawing a recognizable spiral. Bottom: Handwriting "cleaned up" by a new software program.
Cleaning up shaky handwriting
Jittery handwriting is all too familiar to families and friends of people with severe Parkinson's disease. The involuntary tremor of Parkinson's can sometimes make handwriting almost illegible.

But what if a computer could transform wobbly handwriting into penmanship that even a grammar school teacher would approve of? Hopkins biomedical engineers have created software that does just that.

Users of the system write on a digitizing tablet, and a wave form version of the handwriting is fed into a computer. A software program then measures the characteristic frequency of the user's tremor. While tremor frequency varies from one person to the next, each person with Parkinson's disease shakes at a relatively constant frequency. The program then subtracts the tremor frequency, in effect cleaning up the handwriting.

Parkinson's disease patients are not the only ones who might benefit from the technology. Brain injury, multiple sclerosis, and even the natural aging process can lead to pathological tremor, notes Nitish Thakor, professor of biomedical engineering, and the principal investigator. "We're hoping that this software will be useful for people with [such] disabilities," he says. The National Institute of Disability and Rehabilitation Research funded the project.

In fact, everybody shakes, or has some degree of physiological tremor, even--scary as the thought may be--surgeons. Physiological tremor can interfere with certain types of eye surgery conducted with tiny instruments. Thakor's team has built a prototype tool that, he says, could compensate for hand tremor during such microsurgical procedures. The instrument has special motors that are programmed to move the tip of the instrument in an equal but opposite direction to the movement of the tremor, in effect canceling it out. The new instrument, say the investigators, would allow surgeons to be more precise and perhaps even to undertake new surgical procedures that are now only theoretically possible. --MH

Hot colliding balls of fire
Hopkins astronomer
William Blair knows a supernova when he sees one, having studied several including the famous supernova 1987A. But he was perplexed when he examined images of a speck of sky near one of the arms of spiral galaxy NGC 6946, 17 million light-years away. Images taken with a powerful ground-based telescope and the ROSAT X-ray satellite revealed the brightness of a young exploding star, or supernova. However, the object lacked neon and oxygen, telltale chemicals of a recently exploded star. Nor was material exiting the object at the rapid clip seen in young supernovae.

A closer look through the Hubble Space Telescope's Wide Field and Planetary Camera 2 resolved the paradox. "It's not one supernova," Blair concludes. "It's at least two, or even more supernovae slamming together." Astronomers had predicted, but never observed such a phenomenon. The two supernovae probably exploded roughly 20,000 years apart, says Blair.

When a star explodes, it shoots out gas and debris at a speed of 22 million miles per hour, explains Blair. The shock wave of the blast compresses the surrounding interstellar gas and dust into a dense shell of material, much the way a bulldozer pushes dirt forward.

The bright region in NGC 6946 bears the chemical signature of an old supernova and the brightness of a young supernova. "There is so much material bumping together," says Blair. "It heats up the gas, and makes a heck of a lot of light." --MH

Illustration by Jeff Bohlander
Secrets to success of Silicon Valley
Silicon Valley may have it all: idyllic weather, a top-notch university, good coffee. And, apparently, a recipe to economic success that can't be replicated.

Two Hopkins historians recently examined the birth of Silicon Valley--Stanford's famous cradle of a seemingly endless flow of high-tech research and multimillionaires--and found that the corporate Canaan was likely a one-time wonder.

"The lesson of the story is that re-creating something like Silicon Valley is much more difficult than anyone imagined it would ever be," says history of science professor Robert Kargon, who worked with colleague Stuart Leslie on the project. Their paper was published in the June issue of Business History Review.

Historically, the timing couldn't have been better for the birth of the high-tech region. "There were millions and millions of defense dollars flowing into that area after World War II; that is a circumstance that is not likely to repeat anytime soon," notes Leslie. Another one-time-only event: the development of the region's namesake, the computer chip.

While areas like North Carolina's Research Triangle have flourished, they differ from Silicon Valley, Kargon says, because they generally play host to corporate outposts rather than firm headquarters; in other words, intellectual control of the companies resides elsewhere. "That means it's always going to be a satellite to someplace else, where the ideas are created," says Leslie.

Silicon Valley was also unique in its ability to sidestep the culture clash that inevitably seems to occur when industry and academia work in partnership. Unlike the business world, universities traditionally value theoretical work over applied work, and are more interested in publishing than in proprietary research, Leslie notes. At Silicon Valley, says Kargon, "Stanford University and the industries around it were able to establish a mutual understanding of each other's culture." Perhaps just as unusual was the cooperation that occurred between corporations; many start-up companies grew up together as Stanford matured, and were uniquely willing to share information and work together toward common goals.

Even the founder of Silicon Valley, Frederick Terman, was unable to export his idea from the Golden State. His attempts to foster high-tech centers in New Jersey and Texas, with help from Bell Labs and Texas Instruments, both failed, the two researchers note.

What, then, about dreams of a California-style business gold rush for the Baltimore-Washington corridor? Kargon believes there's a chance if biotechnology firms continue to spring from Johns Hopkins and other area universities, but notes, "It's not just a matter of bringing firms and universities together. There has to be a mechanism of interaction...a unity of purpose." --AM

Photo by The Johns Hopkins Applied Physics Laboratory
The asteroid that ate Baltimore
Let's take a Hopkinscentric view of asteroid Mathilde, whose dark, pockmarked countenance was photographed in June by the
Near Earth Asteroid Rendezvous (NEAR) spacecraft. NEAR was built and is managed by the Johns Hopkins Applied Physics Laboratory (APL). At 750 miles, NEAR came closer to Mathilde than any spacecraft ever has to an asteroid. With the guidance of NEAR program manager Andrew Cheng, let's see what would happen if Hopkins and its environs were transported to the craterous rock.


After a smooth flight, the city of Baltimore gently lands in Mathilde's largest (30 kilometers wide) crater. It's early in the morning of the asteroid's 418-hour day. After donning spacesuits, an advance team led by Hopkins geologists sets out to explore the inky landscape. They first scale the canyon wall, an ascent that might be as long as a hike up the Grand Canyon, but far quicker. Gravity on Mathilde is a fraction of what it is on Earth, so that when the travelers intend to jump a foot, they find themselves leaping 1,000 feet or farther. This could be a great place to put Camden Yards, they decide--just imagine how many homeruns there'd be.

Suddenly, one explorer yells, "Look out!" as rubble starts tumbling down the crater. Team members spring out of the way, and make mental notes to plant bright yellow "Mass Wasting" signs on a return trip. Mathilde is a pile of light, carbon-rich rubble, and mass wasting (rubble slides) is a frequent occurrence, APL researchers have found. Finally, the intrepid explorers scramble over the crest of the crater. They brush off the carbon dust that coats their spacesuits, and look up just in time to wave goodbye to NEAR as it flies on to rendezvous with asteroid Eros in January 1999. After circling Eros for a year, NEAR will actually land on the asteroid, if all goes as planned. --MH

Written by Melissa Hendricks and Adam Marcus (MA '96).