George F. Smoot
From Wikipedia
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]
Jadual isi kandungan |
[Sunting] Biografi
[Sunting] Pendidikan dan permulaan penyelidikan
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.
[Sunting] Pengllibatan dalam 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 inhomogenous 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.
[Sunting] Projek masakini
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.
[Sunting] Rujukan luar
- Nobel Prize announcement
- Biography at the Lawrence Berkeley National Laboratory
- Berkeley lab article
[Sunting] Pautan luar
1901: Röntgen 02: Lorentz, Zeeman 03: Becquerel, P.Curie, M.Curie 04: Rayleigh 05: Lenard 06: Thomson 07: Michelson 08: Lippmann 09: Marconi, Braun 10: van der Waals 11: Wien 12: Dalén 13: Kamerlingh Onnes 14: von Laue 15: W.L.Bragg, W.H.Bragg 17: Barkla 18: Planck 19: Stark 20: Guillaume 21: Einstein 22: N.Bohr 23: Millikan 24: Siegbahn 25: Franck, Hertz 26: Perrin 27: Compton, Wilson 28: Richardson 29: de Broglie 30: Raman 32: Heisenberg 33: Schrödinger, Dirac 35: Chadwick 36: Hess, Anderson 37: Davisson, Thomson 38: Fermi 39: Lawrence 43: Stern 44: Rabi 45: Pauli 46: Bridgman 47: Appleton 48: Blackett 49: Yukawa 50: Powell 51: Cockcroft, Walton 52: Bloch, Purcell 53: Zernike 54: Born, Bothe 55: Lamb, Kusch 56: Shockley, Bardeen, Brattain 57: Yang, T.D.Lee 58: Cherenkov, Frank, Tamm 59: Segrè, Chamberlain 60: Glaser 61: Hofstadter, Mössbauer 62: Landau 63: Wigner, Goeppert‑Mayer, Jensen 64: Townes, Basov, Prokhorov 65: Tomonaga, Schwinger, Feynman 66: Kastler 67: Bethe 68: Alvarez 69: Gell‑Mann 70: Alfvén, Néel 71: Gabor 72: Bardeen, Cooper, Schrieffer 73: Esaki, Giaever, Josephson 74: Ryle, Hewish 75: A.Bohr, Mottelson, Rainwater 76: Richter, Ting 77: Anderson, Mott, van Vleck 78: Kapitsa, Penzias, Wilson 79: Glashow, Salam, Weinberg 80: Cronin, Fitch 81: Bloembergen, Schawlow, Siegbahn 82: Wilson 83: Chandrasekhar, Fowler 84: Carlo Rubbia, van der Meer 85: von Klitzing 86: Ruska, Binnig, Rohrer 87: Bednorz, Müller 88: Lederman, Schwartz, Steinberger 89: Ramsey, Dehmelt, Paul 90: Friedman, Kendall, Taylor 91: de Gennes 92: Charpak 93: Hulse, Taylor 94: Brockhouse, Shull 95: Perl, Reines 96: D.Lee, Osheroff, Richardson 97: Chu, Cohen‑Tannoudji, Phillips 98: Laughlin, Störmer, Tsui 99: 't Hooft, Veltman 2000: Alferov, Kroemer, Kilby 01: Cornell, Ketterle, Wieman 02: Davis, Koshiba, Giacconi 03: Abrikosov, Ginzburg, Leggett 04: Gross, Politzer, Wilczek 05: Glauber, Hall, Hänsch 06: Mather, Smoot |
Persondata | |
---|---|
NAMA | Smoot, George Fitzgerald, III |
NAMA LAIN | |
HURAIAN RINGKAS | American astrophysicist and cosmologist |
TARIKH LAHIR | February 20 1945 |
TEMPAT LAHIR | Yukon, Florida |
TARIKH KEMATIAN | living |
TEMPAT KEMATIAN |
[Sunting] Rujukan
- ↑ Information for the public. (PDF) The Royal Swedish Academy of Sciences: (2006-10-03). Dicapai pada 2006-10-05.
- ↑ Templat:Cite press release
- ↑ Smoot, G. F et al., Structure in the COBE differential microwave radiometer first-year maps, Astrophysical Journal 396, L1 (1992)
- ↑ Press release: Pictures of a newborn Universe
- ↑ Wrinkles in Time by George Smoot and Keay Davidson, Harper Perennial, Reprint edition (October 1, 1994) ISBN 0380720442