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Science
Friday > Archives
> 1997
> November
> November 7, 1997
Hour Two: The Future of Railroads / Astronomical "frame dragging"
Imagine being able to zip your way from place to place at speeds approaching
300 kilometers an hour. Many Europeans enjoy this luxury already - high-speed
rail lines are operating successfully in France, Germany, Belgium, and
other countries. Japan has had the Shinkansen, also known as the bullet
train, since 1964. But the United States has no comparable technology
- most U.S. rail lines are currently limited to a top speed of 130 kilometers
an hour.
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Tests using a train similar to Germany's ICE have been conducted
along Amtrak's Northeast Corridor Washington-New York route. A
train similar to France's TGV is slated to operate along the Northeast
Corridor by 1999, cutting New York-Washington travel times to
two hours, 45 minutes. That route accounts for only a tiny fraction
of U.S. rail lines, however, raising questions of whether the
rest of the nation will be left behind on the sidings.
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France's TGV Altlantique, capable
of speeds of up to 300 km/hr.
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Climb on board this hour of Science Friday, as we discuss why it's
taken the U.S. so long to develop high speed rail -- and at what future
train technologies might be waiting down the track.
Plus ...
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Astronomers reported this week that they had seen evidence that
black holes and rapidly spinning stars may distort space and time
in their vicinity. The effect, called "frame dragging" or "Lense-Thirring
precession," was predicted in 1918 by Einstein's theory of relativity,
but had never actually been observed until now.
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image courtesy of
Sky and Telecope Magazine,
artist Joe Bergeron.
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Using NASA's Rossi X-Ray Timing Explorer satellite, Luigi Stella from
the Astronomical Observatory of Rome and Mario Vietri from the Third University
of Rome observed tiny variances in the intensity of x-rays given off by
rapidly spinning neutron stars. A team led by Wei Cui of the Massachusetts
Institute of Technology observed a similar effect -- modulated x-rays
-- given off by clouds of gas being compressed as they swirl into a black
hole's gravitational field. The pattern to the intensity of the x-rays
led them to suspect a variation in the orbit of matter around the stars
and black holes. That variation supports predictions made in 1918 by Joseph
Lense and Hans Thirring based on Einstein's theories.
On this segment of Science Friday, we'll talk to two of the astronomers
who witnessed this dramatic effect, and find out what it means to our
understanding of space and time.
Guests:
Joeseph Vranich
Author
"Derailed:
What Went Wrong and What to Do About America's Passenger Trains"
Past President, High Speed Rail Association
Irvine, CA
James A. Dunn, Jr.
Associate Professor of Political Science
Rutgers University
Camden, NJ
Richard Thornton
Professor of Electrical Engineering
Massachusetts Institute of Technology
Cambridge, MA
Luigi Stella
Osservatorio Astronomico di Roma
Rome, Italy
Wei Cui
Massachusetts Institute of Technology
Cambridge, MA
Books/Articles Discussed:
"Derailed:
What Went Wrong and What to Do About America's Passenger Trains," by
Joeseph Vranich. St. Martin's Press, 1997.
Related links:
The High Speed Ground
Transportation Association
The Department of
Transportation's High Speed Ground Transportation group
France's TGV
Gemany's
ICE
The Railway Technical Research
Institute in Japan, home to advanced mag-lev research
Articles from Scientific American's October 1997 transportation issue:
How High Speed
Trains Make Tracks
Fast Trains:
Why the U.S. Lags
Maglev:
Racing to Oblivion?
An
MIT press release about the frame-dragging discovery
The RTXE
Satellite
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