George Smoot meraikan kejayaan Hadiah Nobel pada 3 Oktober 3, 2006 pada
Makmal Kebangsaan Lawrence Berkeley
.
George Fitzgerald Smoot III
(lahir
20 Februari
1945
) merupakan seorang ahli
astrofizik
dan
kosmologi
Amerika Syarikat
.
Beliau juga merupakan seorang professor fizik di
University of California, Berkeley
. Beliau telah dianugerahkan
Hadiah Nobel dalam Fizik 2006
, berkongsi dengan
John C. Mather
kerana "penemuan mereka terhadap bentuk
jasad hitam
dan
anisotrofi
latarbelakang gelombang mikro kosmik
". Penemuan ini menolong mengukuhkan teori
big-bang
alam semesta menggunakan satelit
COBE
(Cosmic Background Explorer). Merujuk kepada ahli jawatankuasa Hadiah Nobel, "projek COBE boleh dianggap sebagai titik permulaan
kosmologi
sebagai satu sains yang tepat".
[1]
Pendidikan dan permulaan penyelidikan
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Smoot telah lahir pada
20 Februari
1945
di
Yukon
,
Florida
. Beliau telah mempelajari
matematik
sebelum bertukar ke
Massachusetts Institute of Technology
di mana beliau memperolehi dua
sarjana muda
dalam matematik dan fizik dalam 1966, dan satu ijazah
kedoktoran
di
fizik zarah
dalam tahun 1970.
[2]
Kemudian beliau telah bertukar ke bidang kosmologi, dan telah pergi ke
Makmal Kebangsaan Lawrence Berkeley
di mana beliau telah berkolaborasi dengan
Luis Walter Alvarez
berkenaan dengan eksperimen
HAPPE
, satu
belon
stratosfera
bagi mengesan
antijisim
dalam
atmosfera atas
, di mana ia telah diramal oleh
keadaan tetap
model kosmologi
yang kini samar-samar.
Kemudian beliau mengambil minat dalam latarbelakang gelombang mikro kosmik (CMB), sebelum ini ditemukan oleh
Arno Allan Penzias
dan
Robert Woodrow Wilson
. Satu persoalan yang belum diselesaikan pada masa itu adalah struktur
alam semesta
. Certain models predicted the universe to be in
rotation
, which left a trace in the CMB in the form of
temperature
depending on the direction of observation. With the help of Alvarez and
Richard A. Muller
, he developed a differential
radiometer
which measured the difference in temperature of the CMB between two directions 60
degrees
apart. The instrument, which was mounted on a
Lockheed U-2
plane, made it possible to determine that the overall rotation of the universe was null (within the limit of accuracy of the instrument). It detected a variation in the temperature of the CMB corresponding to a
dipole
, interpreted as the
Doppler effect
of the Earth's motion relative to the area of CMB emission, which is called the
last scattering surface
. Such a doppler effect arises because the
Sun
(and in fact the
Milky Way
as a whole) is not stationary, but rather is moving at nearly 600
km/s
with respect to the last scattering surface. This is probably due to the
gravitational attraction
between our galaxy and a concentration of mass like the
Great Attractor
.
Although Smoot attended MIT, he was not the same
Smoot
who was laid end to end to measure the
Harvard Bridge
between
Cambridge
and
Boston
; this was
Oliver R. Smoot
. This confusion was
clarified by George Smoot himself
.
Map of the CMB fluctuations found by COBE.
At that time, the CMB appeared to be perfectly uniform excluding the distortion caused by the Doppler effect as mentioned above. This result contradicted with observations of the universe, with various structures (
galaxies
,
galaxy clusters
, etc.), indicating that the universe was relatively in
homogenous
on a small scale. However, these structures formed slowly. Thus, if the universe is inhomogenous today, it would be inhomogenous at the time of the emission of the CMB as well, observable today through weak variations in the temperature of the CMB. It was the detection of these anisotropies that Smoot was working on in the late
1970s
. He then proposed to
NASA
a project involving a
satellite
equipped with a detector that was similar to the one mounted on the U-2, but was more sensitive and not influenced by
air pollution
. The proposal was accepted and gave rise to the satellite
COBE
, and cost US$ 160 million. COBE was launched on
November 18
,
1989
, after a delay owing to the destruction of the
Space Shuttle Challenger
. After more than two years of observation and analysis, the team of COBE, led by Smoot, announced on
23 April
1992
to have detected negligible fluctuations in the CMB, a breakthrough in the scientific world.
[3]
The success of
COBE
was the outcome of prodigious team work involving more than 1,000 researchers, engineers and other participants. John Mather coordinated the entire process and also had primary responsibility for the experiment that revealed the blackbody form of the CMB measured by COBE. George Smoot had main responsibility for measuring the small variations in the temperature of the radiation
[4]
.
Smoot collaborated with
San Francisco Chronicle
journalist Keay Davidson to write the general-audience book
Wrinkles in Time
[5]
, first published in 1994, that chronicled his team's efforts.
After COBE, Smoot took part in another experiment involving a stratospheric balloon,
MAXIMA
, which was more precise than COBE, and refined the measurements of the anistrophies of the CMB. He is also a collaborator in
SNAP
, a satellite which is proposed to measured properties of
dark energy
, and data from the
Spitzer Space Telescope
in connection with
infra-red
radiation.
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