Online ASP Newsletter
Volume 30, Issue 2
Summer, 2001
Editor: John S. Connolly, Ph.D.
INSIDE THIS ISSUE . . . . .
2001 ASP Award Winners
 |
 |
| At its meeting in the Washington, D.C, area on January 14, 2001, the
ASP Council approved the recommendations of the Grants and Awards Committee
for the Research Award and the New Investigator Award for the year 2001.
Thomas A. Moore received his B.A. and Ph.D. from Texas Tech University,
the latter with Pill Soon-Song as his advisor. He has been in the Department
of Chemistry at Arizona State University since 1976, where he is currently
a professor. He was a member of the ASP Council in 1982-85.
For the last 20 years, Dr. Moore, along with his main collaborators and fellow
ASU faculty members-Ana Moore, his wife, and Devens Gust-has been applying
the principles and techniques of synthetic and physical organic chemistry
to mimicry of biological processes in photosynthesis. Using his expertise
in molecular synthesis, spectroscopic methodologies, and biophysics, Dr.
Moore has studied a large number of complex organic molecular systems that
express important facets of natural photosynthesis.
The results of this body of work have led to a better understanding of the
natural photosynthetic process, uncovered new principles for understanding
and controlling photoinduced electron transfer, singlet- and triplet-energy
transfer, provided new basic principles for the design of photochemical
solar-energy harvesting, and demonstrated the feasibility of prototypical
optoelectronic components at the molecular level. Recently, Dr. Moore and
his colleagues have successfully assembled a functioning artificial
photosynthetic membrane in which light energy drives the generation of the
proton motive force and synthesis of ATP.
Dr. Moore will give the ASP Research Award lecture at the annual meeting
in Chicago on Sunday, July 8, 2001 |
Paola Taroni received her Ph.D. in nuclear engineering from
Politecnico, Milan, Italy, in 1987. She then spent a year as a visiting scientist
at MIT, working on UV-fluorescence spectroscopy for medical diagnosis. From
late 1988 through 1999, she was a staff researcher with the Center for Quantum
Electronics and Electronic Instrumentation (CEQSE) at Politecnico Milano,
where she is currently an associate professor of physics. She is a new member
of the ASP Council.
Dr. Taroni's research activity concerns mainly the development of laser systems
for time-resolved spectroscopy and imaging, and the applications of these
systems in biology and medicine. In particular, she has developed a system
for time-gated fluorescence spectroscopy with picosecond resolution, and
has applied it to the photophysical characterization of various pigments
and photosensitizers for PDT. She has also been engaged in the optimization
of therapeutic protocols for PDT. Over the last few years, she has been working
on the detection of tumors with time-resolved fluorescence imaging.
More recently, she extended her interests to photon migration, and in particular
to time-resolved reflectance spectroscopy for non-invasive optical
characterization of highly diffusive media (such as biological tissues),
and to time-resolved transmittance-imaging techniques for breast cancer detection
(i.e., optical mammography).
Dr. Taroni is scheduled to give the ASP New Investigator Award lecture at
the ASP annual meeting in Chicago on Monday, July 9, 2001.
Other members of the Committee are Charles Gomer, Irene Kochevar, Fran-cesco
Lenci, Frances Noonan and John Spudich.
Henry W. Lim, Chair
Grants and Awards Committee |
Election Results
President-elect
Henry Lim (Division 4)
Councilors
Bridgette Barry (Division 3)
Wolfgang Gärtner (Division 1)
Holly Gorton (Division 5)
Donat Häder (Division 5)
Congratulations to the winners and many thanks to all of the candidates!
Please note that the names of two Divisions have been changed: Division 2
is now "Photosensory and Circadian Biology" and Division 3 is "Photosynthesis
and Luminescence."
Newsletter Editor Wanted
For health reasons, I must step down as editor of ASP News before the end
of September. If you think you might be interested in the job, please feel
free to contact Charlie Yocum, Chair
of the Publications Committee, for details. - JSC (rewrite)
Associate Member Travel Awards
The Grants and Awards Committee has approved 37 applications for the Associate
Member Travel Awards, which will partially support attendance at the 2001
annual meeting by these members.
These awards were made possible through the generous contributions of Don
Forbes and his group, Primedica Argus, and of Tom Dougherty, Barbara Henderson,
and the Oncologic Foundation of Buffalo.
Henry W. Lim, Chair
"The greatest obstacle to discovery is not ignorance; it is the illusion
of knowledge." - Daniel J. Boorstin
Reichard Leaves ASP After 10 Years as Executive
Secretary
Sherwood Reichard came to ASP in 1991 as the Society's first Executive
Secretary who was also a professional administrator, businessman, and scientist.
He managed the Society though his company, Management Association for
Professional Societies (MAPS). Formerly he was Regents' Professor of Radiology,
Physiology and Immunology at the Medical College of Georgia. Before that,
he was Director of the Division of Radiobiology at MCG and Director of the
Institute of Radiation Biology at Florida State University. At other times,
Sherwood served as CEO of Chemical Consultants, Inc., CFO of Crown Colony
Enterprises, a director of Xytex Corp., and President of Health Center Credit
Union. He was also a director on the International Trade Council in Washington.
Dr. Reichard has been President of several national and international societies
including, the Society for Leukocyte Biology, the Reticuloendothelial Society,
the Shock Society, the Forum for Macrophage Biology, and the International
Union of RES Societies. He was also Executive Director of four International
Societies and managed over 200 national and international meetings throughout
the world. Sherwood has published over 200 papers, was editor of Advances
in Experimental Biology and Medicine, has written or edited over 30
scientific books, and is now President and CEO of BioMedical Press, which
publishes scholarly journals and multimedia publications.
A very unassuming person, Sherwood goes out of his way to help members and
officers. He has served the ASP with distinction over the past 10 years,
having organized some 30 Council, Society, and international meetings and
overseeing the Society from a time when it was essentially a "debtor"
organization to one that now boasts assets of over a million dollars, an
outstanding journal, and nearly 1600 members.
Thanks, Sherwood; we'll miss you very much!
John Connolly
ASP News is published quarterly by the
American Society for Photobiology
2000 L St, NW, Ste 710
Washington, DC 20036
Phone: 202-973-8670
Fax: 202-331-0111
E-Mail: ASP@courtesyassoc.com
**********************
Editor: John S. Connolly, Ph.D.
SCIENTIFIC EDITING SERVICES
P.O. Box 16222
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Courtesy Associates Retained as New ASP Secretariat
We are pleased to welcome Courtesy Associates of Washington, D.C., as the
new association management contractor to assist ASP, beginning this fall.
Founded in 1947, Courtesy has provided association and conference-management
services to hundreds of clients over its 54-year history.
We are looking to Courtesy to apply its experience gained from managing other
associations and meetings not only to streamlining administrative duties,
such as dues processing and publications distribution, but also to helping
increase ASP's membership, improve the Annual Meeting, and assist ASP officers
and Board members in enhancing other related areas.
Courtesy has worked with both basic and clinical scientists, so its staff
members are familiar with some of the issues we face. The firm has several
multi-year contracts with various government organizations, including the
National Institutes of Health (with whom Courtesy has worked since the
mid-1970s). Courtesy currently manages seven associations, including the
IEEE Magnetics Society and the International Society for Antiviral Research.
The firm plans 350 conferences and events per year, including several dozen
NIH meetings and nine major conferences for IEEE annually.
Below you will find descriptions of the Courtesy staff members who will work
with us and the tasks you can expect them to perform.
The transition will take place during August and September 2001, so please
give a warm welcome to our new management firm.
Woody Hastings, President
John Spudich, President-elect
Introducing Your New Team From Courtesy Associates
It is my pleasure to introduce ASP's new management team from Courtesy
Associates. Sylvia van Laar and Cecile Phillips will be the
two individuals with whom you will probably interact most.
Sylvia will assume the role of Executive Director. She will be responsible
for supervising the overall administrative and financial management of the
Society, and handling liaison with the Board of Directors. She will oversee
all membership strategy development as well as strategic issues regarding
publications and communications. Her primary day-to-day role will be managing
the Annual Meeting, so she will be the person you will contact with
meeting-related issues.
Sylvia
has over 20 years of management experience with major organizations. She
began her association with Courtesy in 1992. In addition to managing the
World Congress of Gastroenterology, she has worked with other Courtesy clients
in planning events on Increasing Awareness of Heart Disease in Women, various
NIH meetings, conferences sponsored by the National Science Foundation, and
numerous other organizations. Formerly she was employed by another
association-management firm as well as by the American Bankers Association
and the American Psychiatric Association. She has worked nationally as well
as internationally and has managed meetings in Europe, Asia, and South America.
Cecile
will be the Association Pro-gram Manager for ASP. She will be the person
whose voice you will probably hear on the other end of the phone when you
call ASP. She will supervise processing of your dues, send information to
potential and new members, and generally assist with membership issues. She
will also manage the ASP database; coordinate mailings, e-mail messages,
and directory production; and work with Sylvia on financial matters.
In Cecile's eight years with Courtesy, she has managed and supported six
associations and has also managed over 60 conferences for (among others)
the National Institutes of Health, the White House Commission on Complementary
and Alternative Medicine, and the Institute of Electrical and Electronics
Engineers.
Courtesy has a staff of 40, so if either Cecile or Sylvia is out of the office,
rest assured that your needs will be well taken care of by an assistant who
will be trained on your issues.
Sherry Watkins
Director of Marketing
Courtesy Associates
For more information on Courtesy Associates, point your Web browser to
http://www.courtesyassociates.com/.
- Ed.
Farewell From your Editor
Due to health considerations, this will be my last issue as editor of ASP
News. For the last four years, I've had the opportunity to interact with
your officers and councilors as well as with many members whom I had not
previously met. I've also been able to view the broad spectrum of specialties
encompassed by the word "photobiology" from a different perspective. Perhaps
over the next few months, my successor will entertain an occasional article
or two.
In Memoriam, Alan D. Adler, 1932-2000
Alan D. Adler, 68, renowned porphyrin chemist and professor emeritus of chemistry
at Western Connecticut State University, died June 11, 2000, at his home
in West Redding, Connecticut.
Al
received his B.S. degree in chemistry from the University of Rochester in
1953 and his Ph.D. degree in physical chemistry seven years later from the
University of Pennsylvania. His career began at Penn, where he joined the
faculty as an assistant professor of molecular biology. In 1967, he joined
the staff of the New England Institute in Ridgefield, Conn., holding the
concurrent posts of professor, senior staff scientist, and chairman of the
Chemical Sciences Division. He joined Western Connecticut State in 1974 and
four years later cofounded its biochemistry program.
Al's interdisciplinary work dealt mainly with the biophysical chemistry of
porphyrinic materials but he also carried out photovoltaic studies of porphyrin
films and mechanistic synthetic studies of heme proteins in nitrite-pollution
problems. His landmark synthesis of tetraphenyl-porphyrin in 1967 can fairly
be said to have paved the way for the great variety of porphyrin research
that followed. Because of his extensive porphyrin studies and encyclopedic
knowledge, he was considered an authority on blood chemistry.
In 1977, Al agreed to do a "weekend's worth" of analysis on a controversial
religious artifact, the Shroud of Turin. The initial short-term project became
a career interest, lasting more than 20 years and taking him around the world
as a member of the Shroud of Turin Research Project and as an ACS Tour Speaker
on the subject.
Though he formally retired from the university in 1992, Al continued to teach
biochemistry through the spring of 2000. In addition to his teaching and
research, he was active in several organizations, including the American
Chemical Society, American Institute of Chemists, the American Physical Society,
the American Association for the Advancement of Science, the American Association
of Clinical Chemists, the American Society for Photobiology, and Sigma Xi.
He joined ASP in 1972.
Over the years, Al was very generous in sharing his samples and his knowledge
with a large number of people working on various aspects of porphyrins. His
passing was acknowledged at the First International Conference on Porphyrins
and Phthalocyanines held in Dijon in June 2000. He should have been there!
Adapted with permission from Chemical and Engineering News, March 5, 2001,
by John Connolly with additional comments by Martin Gouterman.
"Only those who risk going too far can possibly find out how far one can
go." - T.S. Eliot
In Memory of Laura Polo
Laura Polo passed away on February 20, 2001, at the age of 37. A postdoc
in the Biology Department of Padova University, Laura was a beautiful, enchanting
young lady, a brilliant scientist, and an adorable and dear friend.
She was the first young scientist in Italy to earn a Ph.D. in
Photobiology. She devoted her research mainly to the field of photodynamic
activity, but she was interested in a wide variety of scientific and cultural
questions and was always open to new ideas.
Laura had been fighting breast cancer for seven years with extraordinary
fortitude and full consciousness that her life was in danger. She ceaselessly
committed herself to give her precious contribution to the scientific activity
of her research group.
All of her friends and colleagues remember when she gave a talk after her
first chemotherapy, in 1994, at a joint meeting of the Italian Photobiology
and Photochemistry Societies. As usual, it was a superb scientific talk,
presented with her luminous smile, as if she had just come back after a relaxing
journey.
For many years, Laura received awards and fellowships to attend and contribute
to national and international congresses. In 2000, she received her last
grant to participate in the International Congress of Photobiology in San
Francisco. She was unable to attend because of her health, but she kept asking
all of her colleagues who were there to acquaint her with the topics she
was interested in. Her last paper was published in December 2000.1
At her funeral, one of her closest friends read the following message:
"We want to remember you for your great will to live and for the serene joy
that shone from your face, making it brighter than the sun. Your light
illumin-ated what we might never have seen, and you filled our life with
happiness. We want to remember you for the courage you showed in the difficult
moments of your life, that same courage, which had its roots in the frankness
of your heart. We want to remember your tenacity, your strength, and your
honesty, which gave courage to those close to you. Clear as spring water
and limpid were your eyes. This is how we want to remember you and keep you
in our hearts forever. Ciao, Laura!"
Francesco Lenci
Istituto Biofisica CNR, Pisa, Italy
1L. Polo, A. Segalla, G. Bertoloni, G. Jori, K. Schaffner, and
E. Reddi (2000) "Polylysine-porphycene conjugates as efficient photosensitizers
for the inactivation of microbial pathogens," J. Photochem. Photobiol. B:
Biol. 59, 152-158.
Final Program, 29th Annual ASP Meeting
For the final program of the 29th Annual ASP Meeting, please point your browser
to
http://www.pol-us.net/ASP_Home/Meetings/Annual2001/29asp04.html.
Laser Light, Drugs Erase Brain Tumor
Surgeons were somewhat in the dark when they operated on Rick Myers' brain
tumor. It wasn't due to a power failure or a lack of knowledge about the
cancer. Myers, 41, a civil engineer who lives in West Deer, Pa., was [undergoing]
photodynamic therapy, which researchers at the Western Pennsylvania Hospital
are studying as a treatment for brain tumors.
In photodynamic therapy [PDT], the patient is intravenously given a
light-activated drug called porfimer sodium. Normal brain cells rapidly excrete
the drug, but it lingers in tumor cells.
A day after the infusion, surgeons cut away the tumor, then [applied] laser
light to the site. The light activates the drug, causing the release of a
toxic form of oxygen molecule that then kills any remaining cancer cells.
Because the drug also lingers in skin cells, surgeons covered up the windows
in the operating room to protect Myers. Minutes of direct sunshine could
have given him a severe burn.
For six weeks after the Nov. 25 surgery, Myers stayed out of the sun. That
wasn't hard to do during gloomy winter days, Myers said, and the inconvenience
was worth it.
Before surgery, a large mass occupied the right side of Myers' brain just
above the eye. Now, Myers said, doctors can't find any remaining tumor.
The father of three was one of two local patients that West Penn doctors
have enrolled in a national study to gauge the effectiveness of photodynamic
therapy on brain tumors. Photodynamic therapy already is federally [FDA]
approved to treat some esophageal cancers and early lung cancer. Recently,
it also was approved for use in advanced lung cancer when a tumor is obstructing
a large airway, causing symptoms such as coughing or bleeding.
Myers was diagnosed with the late-stage cancer a few days before Christmas
1997. Earlier that month, Myers had brief episodes of severe headache and
visual disturbances. "It was like looking through a kaleidoscope," or a
rain-spattered windshield, he explained.
A brain scan revealed... a glioma [tumor]. Myers had [undergone] surgery
a year [earlier at Pittsburgh's] St. Francis Medical Center to remove a
golf-ball-sized tumor, but not all the disease could be cut out. Radiation
treatments and chemotherapy at West Penn followed, but the cancer kept growing.
In August, [surgeons] implanted tiny radioactive seeds into the tumor. The
cancer shrunk, and the seeds were removed a week later, but some diseased
tissue remained.
Dr. Robert Selker, director of West Penn's Center for Neurooncology, then
suggested Myers participate in [a] trial of photodynamic therapy, [which
was being] sponsored by the National Institutes of Health.
Surgeons can remove only the tumor they can see, but the drug-and-laser treatment
could kill microscopic cancer cells that may be left behind, Selker said.
According to Selker, the cells that can't be seen are the reason the brain
tumors grow back. About 85 percent of recurrences occur in the margins around
the tumor site of tumor removal, despite radiation therapy and chemotherapy.
Researchers have focused on treating the surrounding tissue in hopes of
prolonging survival. Only half [the] patients with late-stage disease are
alive 51 weeks after standard treatments. But preliminary studies showed
[PDT] extends that survival time by 40 more weeks, Selker said.
[PDT] can be used [only in] tumors that are readily accessible. The American
Cancer Society estimates that 16,800 people are diagnosed with brain tumors
or other nervous system cancers each year. Selker said about 10 percent of
brain cancers [are] inoperable.
West Penn is one of four centers contributing to the current trial. One other
local patient has participated, and more than 50 brain procedures have been
done at the other centers.
"It's not a miracle drug, but it is a very important addition to our
armamentarium against lung cancer and esophagus cancer," Dr. Jim Luketich,
a thoracic surgeon at the University of Pittsburgh Medical Center, said of
[PDT]. About 100 esophageal and 45 lung procedures have been performed [there].
Researchers around the country are examining the therapy's effectiveness
in skin cancer, recurrences of breast cancer, and vocal-cord tumors.
"I think it's a little too early... to say if it's going to be a permanent
addition to the treatment of brain cancer," Luketich said. "But it is an
important area of research."
Anita Srikameswaran
Pittsburgh Post-Gazette Staff Writer
January 15, 1999
(Reprinted with permission)
While the Web provides a wonderful vista from which to explore the information
explosion, direct communication with investigators in the area is even better.
Please drop me a line if you have any up-to-date information on experimental
treatments of internal-organ tumors.
By the way, if you haven't heard about the Cerus Helinx™ system for
photodynamic treatment of HIV in donor blood, go to
http://www.ceruscorp.com/pages/solution/cerussolutionA.html.
Auf wiedersehen ! - John Connolly
Mentoring Lunch in Chicago
The annual ASP Mentoring Lunch will be held on Wednesday, July 11, from noon
to 1:30 pm in the Avenue Ballroom of the Marriott Hotel. This event is being
organized by Kathryn Woodburn and David Kessel. All students who have received
travel awards are invited, and we want to have a select number of mentors
on hand to give out good advice in return for great food. The organizers
extend you an invitation to attend this lunch and to share some of your
entertaining experiences in research and grant gathering with the group.
If you are willing to undertake this grave responsibility, please reply to
KWoodburn@pcyc.com and we'll reserve
a place.
Scientists Probe the Light and Dark Sides of Light
It can heal, benefit heart patients, cause skin cancer, damage microscopic
organisms
Light and life: They have an intimate connection.
Light might help to prevent a small percentage of heart attacks if doctors
shine it into an unusual place-the interior of human arteries-scientists
said at a conference in San Francisco.
Also, conferees at the 13th International Congress on Photobiology... had
this warning for beachgoers and sun worshipers: Now that summer is here,
don't assume your suntan lotion will protect you against skin cancer. It
may not.
Meanwhile, excessive ultraviolet light from the sun is already damaging the
genes of microscopic Antarctic organisms, researchers say.
That's some of the latest news from the science of photobiology. More than
1,000 practitioners of this small but thriving science... descended on The
City for a six-day conference at the Hyatt Embarcadero.
"Photobiology is an extremely broad field-it covers topics from vision to
photosynthesis to skin-cancer therapies," observes Francis P. Gasparro, president
of the organizing committee for the conference.
Beaming light into arteries
Some time within the next year, researchers at the Mayo Clinic and elsewhere
may begin beaming light into human arteries. The goal: to see if light prevents
arteries from re-clogging after a special type of heart surgery, Gasparro
said.
In recent years, a popular kind of heart surgery has involved the insertion
of a long catheter, which carries a small balloon, into an artery feeding
into the heart. The catheter is routed toward the artery via a wide vein
in the leg.
Once the catheter-remotely operated by a surgeon-reaches the desired artery,
he or she inflates the balloon. The balloon flattens out accumulated plaques
that are blocking blood flow. Ideally this method-transluminal balloon
angioplasty-allows the resumption of normal, unblocked blood flood into the
heart.
However, in a small percentage of cases, the artery clogs up again within
months. What might be done to prevent such re-clogging of the artery?
A novel solution, now being tested on lab animals, involves sliding a fiber-optic
tube through the catheter into the heart. The fiber-optic line can transmit
an intense beam of light to the site of the clogging.
Healing scar tissues
Scientists suspect that by illuminating the arterial interior for several
minutes, they might be able to hasten the healing of scar tissue that would
otherwise seed future clogging.
Why would a beam of light accelerate wound healing? Past research indicates
that light accelerates wound healing in surface skin, perhaps by stimulating
the skin's immune system. Hence it's worth seeing if the same thing will
happen inside arteries, Gasparro says.
Lab tests of the procedure on rabbits and pigs have been "very encouraging,"
said Gasparro, a professor of physical chemistry at Thomas Jefferson University
in Philadelphia who is not directly connected with the research.
However, "it's too early to say whether this approach (to preventing future
arterial closure) is efficacious. No one has yet done a clinical study in
humans," said Gasparro.
He said human tests might begin within a year at the Mayo Clinic in Rochester,
Minn., and elsewhere.
The science of photobiology began to attract public attention in the 1970s,
when scientists began fearing a future epidemic of skin cancer caused by
increasing solar ultraviolet (UV) light.
Destroying the ozone layer
UV levels would rise, they forecast, because... chloro-fluorocarbons (CFCs)
were slowly destroying the atmospheric ozone layer. The ozone layer normally
shields us from cancer-causing solar radiation.
In that regard, scientists at the meeting issued an important warning Tuesday:
They still haven't found convincing scientific evidence that suntan lotions
protect against a wide variety of skin cancers.
True, there is "limited evidence" that suntan lotion protects against one
type of cancer and another, pre-cancerous condition, Gaparro said. However,
he warned, there is no clear evidence that suntan lotion protects against
many types of skin cancer.
Gasparro based his comments on a report... by Antony R. Young of St. John's
Institute of Dermatology in London. Young, Gasparro said, is "the premiere
researcher in sun-screen photobiology."
[According to] Gasparro..., Young reported "limited evidence" that suntan
lotion may protect against a type of skin cancer called squamous cell carcinoma
and a pre-cancerous condition dubbed actinic keratosis.
Yet science still has "not established" the ability of suntan lotion to protect
against skin cancer in general, Young cautioned in an abstract of his talk.
"All the information isn't in... We need to do more research," Gasparro said.
Formation of the ozone hole
Also at the conference, researchers discussed how polar organisms' genes
are being damaged by increased UV radiation in the Antarctic. In recent years
Antarctic UV levels have risen because of the formation of the so-called
"ozone hole," a dramatic deterioration of the ozone layer over the icy continent.
Earlier [in the] week, researcher Anita Buma of the University of Groningen
in the Netherlands reported finding gene damage in two types of microscopic
inhabitants of Antarctic waters: marine phytoplankton and bacterial
phytoplankton.
The creatures appear to have suffered more genetic damage caused by UV light
than related creatures inhabiting the Red Sea, which is at a tropical latitude,
Buma told conferees.
Another conferee, research ecologist Lara Hansen of the U.S. Environmental
Protection Agency's Gulf Ecology Division in Gulf Breeze, Fla., praised Buma's
study. However, Hansen added, it's too early to consider the genetic damage
"a dire development."
Rather, Hansen said, more research is needed. "We're just beginning to get
a handle on how to measure (this kind of genetic) damage in the field," she
said.
Keay Davidson
San Francisco Examiner Science Writer
July 5, 2000
(http://www.sfgate.com/cgi-bin/article.cgi?file=/examiner/
archive/2000/07/05/NEWS15309.dtl-sections)
(Reprinted with permission-finally! This is the article for which I was
unable to get reprint permission in time for either the Winter or Spring
2000 issues.)
Can Light Break Its Own Speed Limit?
Scientists have apparently broken the universe's speed limit.
For generations, physicists believed there is nothing faster than light moving
through a vacuum-a speed of 186,000 miles per second.
But in an experiment in Princeton, N.J., physicists sent a pulse of laser
light through cesium vapor so quickly that it left the chamber before it
had even finished entering.
The pulse traveled 310 times the distance it would have covered if the chamber
had contained a vacuum.
Researchers say it is the most convincing demonstration yet that the speed
of light-supposedly an ironclad rule of nature-can be pushed beyond known
boundaries, at least under certain laboratory circumstances.
"This effect cannot be used to send information back in time," said Lijun
Wang, a researcher with the private NEC Institute. "However, our experiment
does show that the generally held misconception that `nothing can travel
faster than the speed of light' is wrong."
The results of the work by Wang, Alexander Kuzmich and Arthur Dogariu were
published in Thursday's issue of the journal Nature.
The achievement has no practical application right now, but experiments like
this have generated considerable excitement in the small international community
of theoretical and optical physicists.
"This is a breakthrough in the sense that people have thought that was
impossible," said Raymond Chiao, a physicist at the University of California
at Berkeley who was not involved in the work. Chiao has performed similar
experiments using electric fields.
In the latest experiment, researchers at NEC developed a device that fired
a laser pulse into a glass chamber filled with a vapor of cesium atoms. The
researchers say the device is sort of a light amplifier that can push the
pulse ahead.
Previously, experiments have been done in which light also appeared to achieve
such so-called superluminal speeds, but the light was distorted, raising
doubts as to whether scientists had really accomplished such a feat.
The laser pulse in the NEC experiment exits the chamber with almost exactly
the same shape, but with less intensity, Wang said.
The pulse may look like a straight beam but actually behaves like waves of
light particles. The light can leave the chamber before it has finished entering
because the cesium atoms change the properties of the light, allowing it
to exit more quickly than in a vacuum.
The leading edge of the light pulse has all the information needed to produce
the pulse on the other end of the chamber, so the entire pulse does not need
to reach the chamber for it to exit the other side.
The experiment produces an almost identical light pulse that exits the chamber
and travels about 60 feet before the main part of the laser pulse finishes
entering the chamber, Wang said.
Wang said the effect is possible only because light has no mass; the same
thing cannot be done with physical objects.
The Princeton experiment and others like it test the limits of the theory
of relativity that Albert Einstein developed nearly a century ago.
According to the special theory of relativity, the speed of particles of
light in a vacuum, such as outer space, is the only absolute measurement
in the universe. The speed of everything else-rockets or inchworms-is relative
to the observer, Einstein and others explained.
In everyday circumstances, an object cannot travel faster than light.
The Princeton experiment and others change these circumstances by using devices
such as the cesium chamber rather than a vacuum.
Ultimately, the work may contribute to the development of faster computers
that carry information in light particles.
Not everyone agrees on the implications of the NEC experiment.
Aephraim Steinberg, a physicist at the University of Toronto, said the light
particles coming out of the cesium chamber may not have been the same ones
that entered, so he questions whether the speed of light was broken.
Still, the work is important, he said: "The interesting thing is how did
they manage to produce light that looks exactly like something that didn't
get there yet?"
Alex Dominguez
Associated Press Writer
(Updated 8:03 PM ET July 19, 2000; reprinted with permission.)
More About the Speed of Light
For a respected physicist to suggest that it's possible for something to
travel faster than light, is rather like a geologist declaring that the earth
is flat. But as NPR's David Kestenbaum reports, [the July 20, 2000] issue
of the prestigious journal Nature contains a paper that claims exactly that.
(http://search.npr.org/cf/cmn/cmnps02fm.cfm?mm=7&yy=2000&PrgID=2)
In another NPR report, Alex Chadwick talks with the "Math Guy," Keith Devlin,
dean of science at St. Mary's College in Moraga, California. They discuss
attempts by physicists to beat the speed of light.
(http://search.npr.org/cf/cmn/mnpd01fm.cfm?PrgDate=6%2F24%2F2000&PrgID=7)
"Reality is merely an illusion, albeit a very persistent one." -
Albert Einstein
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Photobiology in the News
Q&A: Ultraviolet Damage
Q. How does ultraviolet radiation cause skin cancer?
A. The prevailing theory involves damage to the DNA of skin cells,
said Dr. Darrell Rigel, a professor of dermatology at New York University.
It is the shorter [wavelength] UVB rays, which penetrate only the top layers
of the skin, that are suspect, while the longer [wavelength] and more deeply
penetrating UVA rays cause wrinkles and aging.
"In tissue cultures, UV damages the DNA of cells, but humans have an enzyme
that repairs it," he said. "In a genetic defect, some people lack the repair
enzyme. How does this convert to skin cancer? The hypothesis is that in the
body such DNA damage occurs all the time and is constantly repaired, but
some cells do not get repaired, or get repaired improperly, and this is how
skin cancer begins."
Researchers found a specific kind of DNA damage in a gene called p53 that
occurs in this way. In the error, two DNA units of the type designated as
thymine are side by side, instead of two units of the cytosine type. The
error is called a thymine dimer. It is presumed that the brakes on cell
multiplication come off because of it, leading to uncontrolled proliferation
of cells into a tumor.
UV radiation is implicated in the vast majority of non-melanoma skin cancers,
like basal cell carcinoma and squamous cells carcinoma, according to the
American Cancer Society. It is also linked to melanoma, though less clearly.
C. Claiborne Ray
The New York Times
March 6, 2001