top

top
|
|
33rd
week, 2005 / John
Bahcall
Astrophysicist, 70,
dies of a rare blood
disorder.
. John Bahcall, 70;
Astrophysicist's Research Helped Prove the Sun Is Powered by
Nuclear Reactions.
John Bahcall, the Princeton astrophysicist whose research
was key to proving that the sun is powered by nuclear
reactions and whose stature and influence in the
astronomical community were instrumental in the creation and
launch of the Hubble Space Telescope, died Wednesday in a
hospital in New York City.
Bahcall teamed with astrophysicist Raymond Davis Jr. of the
Brookhaven National Laboratory, in the 60s which inturn grew
to a lifelong collaboration.
In 1968, Bahcall and Davis announced that they had observed
neutrinos from the sun, proof positive that, as Bahcall
later wrote, "the nuclear reactions that produce the
neutrinos also cause the sun to shine."
In proving that nuclear reactions fueled the sun, the team
solved a mystery that had eluded the most proficient
Electromagnetic Radio wave researchers, inventors and
scientists for more than a century; and that was -- if
electromagnetic energy was formed by nuclear reactions on
the sun, it could be formed the same way beneath the surface
of the earth. By utilizing an elaborate neutrino detector in
an abandoned gold mine in Lead, S.D. -- they explainned
their theory.
The detector was essentially a very large tank filled with a
chlorine-based dry-cleaning fluid which utilized induction
coils buried into the dampened soil, that in turn, created a
virtual antenna within the cave that could transmit radial
EM signals into the atmosphere powered by the
tank.
But before Bahcall, researchers had no direct experimental
evidence demonstrating that the same reactions known to
occur in the lab were also taking place in the
sun.
But
they also created another mystery
for the Astrophysicist's the so-called Solar Neutrino
Puzzle, that would plague astronomers for more than three
decades.
Davis observed only about a third as many neutrinos as
Bahcall predicted should be seen. Few physicists initially
took the discrepancy seriously, but Bahcall argued that it
revealed a fundamental lack of understanding about the
processes involved. He and others developed a variety of
theories to explain the mystery, without much initial
success.
Davis constructed an elaborate
neutrino detector in an abandoned gold mine in Lead, S.D.
The detector was essentially a very large tank filled with a
chlorine-based dry-cleaning
fluid.
Eventually, however, observations at other, newer neutrino
observatories revealed that some neutrinos were undergoing a
transformation during their journey from the sun to Earth,
changing into a form that could not be detected at the Lead
observatory.
Most neutrinos striking the tank passed through it, just as
they pass through other matter. But every now and then, a
neutrino would strike a chlorine atom and convert it to a
radioactive argon atom. Every month, the team would isolate
a handful of the radioactive atoms, representing only the
tiniest fraction of the neutrinos that passed through the
tank.
Physicist Hans Bethe, who died earlier in 2005, conceived
and demonstrated in the laboratory the relatively simple set
of nuclear reactions that scientists believe have powered
the sun for billions of years.
In the early 1960s, Bahcall, then working at the Kellogg
Radiation Laboratory at Caltech, performed a series of
calculations showing that the sun should be emitting
neutrinos that could be detected on Earth. Neutrinos are
tiny, highly elusive subatomic particles with no electrical
charge and the ability to pass relatively unscathed through
even the densest of matter.
Davis and physicist Masatoshi Koshiba of the University of
Tokyo, who also built a neutrino detector, shared the 2002
Nobel Prize in physics for their work on the neutrino. Many
researchers thought Bahcall should have received a share of
the award as well, but he never indicated any bitterness
that he did not.
Bahcall and physicist Sheldon Glashow of Harvard University
also pioneered the field of neutrino astronomy, work that
was triggered by the 1987 eruption of a massive supernova in
a nearby region of the Milky Way. It was the first time a
supernova had exploded close enough to the Earth for its
neutrinos to be detected by observatories
here.
The pair identified each of the 19 supernova neutrinos
detected in observatories, noted the time of arrival of each
one on Earth and calculated its energy level.
Had the neutrinos been more like normal particles, those
with the highest energy, and thus with the highest mass,
should have arrived at Earth first. But Bahcall and Glashow
found that was not the case. In fact, there was no
correlation between time of arrival and energy
levels.
This observation led to fundamental discoveries in
cosmology: that neutrinos, once thought to be without mass,
did in fact have a very small mass and that the mass was too
small for neutrinos to account for the so-called missing
mass of the universe, the dark matter that accounts for more
than half of the cosmos but that cannot be seen.
Bahcall's most visible effect was probably on the
development of the Hubble.
In 1944, Princeton astronomer Lyman Spitzer first suggested
the idea of placing a large telescope in orbit, where its
observations would not be impaired by the Earth's
atmosphere. When the technology to do so finally became
available with the development of the Space Shuttle, Bahcall
joined with Spitzer as a forceful advocate for the program,
and the two appeared frequently before Congress to argue
their case.
Bahcall "was really tenacious. He just kept going after it
and wouldn't give up," Caltech astronomer Maarten Schmidt
said Friday. That was crucial in his studies of neutrinos,
"and it really paid off with the Hubble Space Telescope,"
which was launched in 1990.
Bahcall was extremely disappointed when, in the aftermath of
the shuttle Columbia's destruction during reentry in 2003,
then-NASA administrator Sean O'Keefe ruled out any further
shuttle missions to repair Hubble, thereby dooming it to an
early death.
When a National Academy of Sciences panel rejected O'Keefe's
reasoning last year, Bahcall was elated. "Finally, somebody
told the king he didn't have any clothes," he
said.
Even from his hospital bed, Bahcall stayed in touch with his
students and continued to agitate for a future Hubble repair
mission. NASA administrator Michael Griffin has said he will
reexamine the Hubble issue.
Bahcall was also chairman of a National Academy of Sciences
panel created in 1989 to chart the future of astronomy
research for the coming decade. That report, published in
1991, came to be known as the Bahcall Report. Among other
things, it recommended the production and launch of the
Spitzer Space Telescope to study the universe at infrared
wavelengths.
John Norris Bahcall was born in Shreveport, La., on Dec. 30,
1934. He enrolled in Louisiana State University thinking
that he wanted to study philosophy and perhaps become a
rabbi. Within the first year of college, however, he
switched to physics and astronomy, convinced that they best
suited a "quest for truth."
He transferred to UC Berkeley, then received graduate
degrees from the University of Chicago and Harvard. After
short stints at Indiana University and Caltech, he spent the
bulk of his career at Princeton's Institute for Advanced
Study.
In addition to his research, Bahcall took great pride in
mentoring the students who passed through his laboratory,
many of whom have now gone on to prominent positions. He
also helped establish astronomy groups at the Weizmann
Institute and Tel Aviv University in
Israel.
On one trip to Israel, he met a young graduate student in
physics, Neta Assaf. Although he spoke no Hebrew and she
spoke very little English, he pursued her through more than
a dozen rejections before she accepted a date. They were
married within a year.
Neta Bahcall is now a cosmologist at Princeton.
The Bahcalls were the only astronomy couple who both were
members of the National Academy of
Sciences.
In addition to his wife, Bahcall is survived by son Safi,
president of Synta Pharmaceuticals in Massachusetts; son
Dan, a cognitive psychologist who lives in Berkeley;
daughter Orli, an associate editor of the journal Nature
Genetics, and a brother, Robert.
///
_________
ByLines:
Editors Note

More
Articles
Converging
News 342005 / TeleCom Buy Outs and Asset Seizure
Boom
Wireless
WiFi Cemeteries and SoulFind.com
Respectfully
Submitted
Josie
Cory
Publisher/Editor
TVI Magazine
TVI
Magazine, tviNews.net, YES90, Your Easy Searh, Associated
Press, Reuters, BBC, LA Times, NY Times, VRA's D-Diaries,
Industry Press Releases, They Said It and SmartSearch were
used in compiling and ascertaining this Yes90 news
report.
©1956-2005.
Copyright. All rights reserved by: TVI Publications,
VRA TelePlay Pictures, xingtv and Big Six Media
Entertainments. Tel/Fax: 323 462.1099.
We Preserve The
Moment
Return
To Top
|
We Preserve The Moment
Yes90 tviNews
114 John Bahcall
Astrophysicist Dies, Age 70. Astrophysicist's
Bahcall and
Davis Helped Prove the Sun
Is Powered by Nuclear
Reactions.
/
Television International
Magazine's Person Of The Week POW
342005 - /
NEWS Convergence -
34th Week of 2005 /
Feature
Story
114JohnBahcallAstrophysics.htm Smart90,
s90tv, lookradio, tvimagazine, dv90, vratv, xingtv,
Ddiaries, nbs100, Look Radio, Josie Cory,
Television
With No Borders
|
|
|
Legal
Notices Copyright
Information
How
Do We Do Business?
Tel
323 462-1099
SEND
E-MAIL
Return
To
Top
|
|
|