Tuesday, 1 May 2007

A Brief History of Time


From The Big Bang to Black Holes

A Brief History of Time  
BriefHistoryTime.jpg
Author(s)Stephen Hawking
LanguageEnglish
Genre(s)Popular science
PublisherBantam Dell Publishing Group
Publication date1988
Media typeBook
Pages256
ISBN9780553109535
OCLC Number39256652
Dewey Decimal523.1 21
LC ClassificationQB981 .H377 1998
Followed byBlack Holes and Baby Universes and Other Essays

A Brief History of Time (subtitled "From the Big Bang to Black Holes") is a popular science bookwritten by Stephen Hawking and first published by the Bantam Dell Publishing Group in 1988.

  It became a best-seller and has sold more than 10 million copies.

  It was also on the London Sunday Times best-seller list for more than four years.

A Brief History of Time attempts to explain a range of subjects in cosmology, including the Big Bang, black holes and light cones, to the nonspecialist reader.

Its main goal is to give an overview of the subject but, unusual for a popular science book, it also attempts to explain some complexmathematics.

The author notes that an editor warned him that for every equation in the book the readership would be halved, hence it includes only a single equation: E = mc2.

In addition to Hawking's notable abstention from presenting equations, the book also simplifies matters by means of illustrations throughout the text, depicting complex models and diagrams.

The book ends with: "If we find [a unified theory], it would be the ultimate triumph for then we would know the mind of God."

A Brief History of Time attempts to explain a range of subjects in cosmology, including the Big Bang, black holes and light cones, to the nonspecialist reader. Its main goal is to give an overview of the subject but, unusual for a popular science book, it also attempts to explain some complex mathematics. The 1996 edition of the book and subsequent editions discuss the possibility of time travel and wormholes and explore the possibility of having a universe without a quantum singularity at the beginning of time.


The author notes that an editor warned him that for every equation in the book the readership would be halved, hence it includes only a single equation: E = mc2. Early in 1983, Hawking approached Simon Mitton, the editor in charge of astronomy books at Cambridge University Press, with his ideas for a popular book on cosmology.

Mitton was doubtful about all the equations in the draft manuscript, which he felt would put off the buyers in airport bookshops that Hawking wished to reach. It was with some difficulty that he persuaded Hawking to drop all but one equation.

In addition to Hawking's notable abstention from presenting equations, the book also simplifies matters by means of illustrations throughout the text, depicting complex models and diagrams.

  • 1988: First edition. It included an Introduction by Carl Sagan that tells the following story: Sagan was in London for a scientific conference in 1974, and between sessions he wandered into a different room, where a larger meeting was taking place. "I realized that I was watching an ancient ceremony: the investiture of new fellows into the Royal Society, one of the most ancient scholarly organizations on the planet. 
  • In the front row, a young man in a wheelchair was, very slowly, signing his name in a book that bore on its earliest pages the signature of Isaac Newton... Stephen Hawking was a legend even then." In his Introduction, Sagan goes on to add that Hawking is the "worthy successor" to Newton and P. A. M. Dirac, both former Lucasian Professors of Mathematics.
The Introduction was removed after the first edition, as it was copyrighted by Sagan, rather than by Hawking or the publisher, and the publisher did not have the right to reprint it in perpetuity. Hawking wrote his own introduction for later editions.
  • 1996: Illustrated, updated and expanded edition. This hardcover edition contained full color illustrations and photographs to help further explain the text, as well as the addition of topics that were not included in the original book.
  • 1998: The Tenth Anniversary Edition. It features the same text as the one published in 1996, but was also released in paperback and has only a few diagrams included.
September 2005 saw the release of A Briefer History of Time (a collaboration with Leonard Mlodinow), which is an abridged version of the original book. It was updated again to address new issues that have arisen due to further scientific development.

Sumber;

Wikipedia

Friday, 20 April 2007

Data Analysis and Archive for CGRO



The Compton Gamma Ray Observatory (CGRO) was a space observatory detecting light from 20 KeV to 30 GeV in Earth orbit from 1991 to 2000. It featured four main telescopes in one spacecraft covering x-rays and gamma-rays, including various specialized sub-instruments and detectors. Following 14 years of effort, the observatory was launched on the Space ShuttleAtlantis, mission STS-37, on 5 April 1991 and operated until its deorbit on 4 June 2000. It was deployed in low earth orbit at 450 km (280 mi) to avoid the Van Allen radiation belt. It was the heaviest astrophysical payload ever flown at that time at 17,000 kilograms (37,000 lb).

The CGRO was part of NASA's Great Observatories series, with the Hubble Space Telescope, the Chandra X-ray Observatory, and the Spitzer Space Telescope. It was the second of theNASA "Great Observatories" to be launched to space, following the Hubble Space Telescope. CGRO was named after Dr. Arthur Holly Compton (Washington University in St. Louis), Nobel prize winner, for work involved with gamma ray physics. CGRO was built by TRW (now Northrop Grumman Aerospace Systems) in Redondo Beach, CA. CRGO was an international collaboration and additional contributions came from the European Space Agency and various Universities, as well as the U.S. Naval Research Laboratory,

Data Analysis for CGRO

BATSE
COMPTEL
EGRET

Wednesday, 18 April 2007

A space observatory The Compton Gamma Ray Observatory (CGRO)

Edited by:
Arip Nurahman
(Teacher and Professional Lecturer)
Guru dan Dosen Profesional
Amin



Compton Gamma Ray Observatory
Cartoon CGRO.jpg
General information
NSSDC ID 1991-027B
Organization NASA
Major contractors TRW
Launch date 5 April 1991
Launched from Kennedy Space Center
Launch vehicle Space Shuttle Atlantis STS-37
Mission length 9 years, 2 months
Deorbited 4 June 2000
Mass 17,000 kg (37,000 lb)
Orbit height 450 km (280 mi)
Orbit period 90 min (1.5 h)
Telescope style Scintillation detectors
Wavelength Gamma
Diameter N/A
Collecting area Varies by instrument
Focal length N/A
Instruments
BATSE all-sky monitor
OSSE pointed detectors
COMPTEL imaging telescope
EGRET wide field telescope
Website NASA Compton Gamma Ray Observatory


Space observatory

A space observatory is any instrument in outer space which is used for observation of distant planets, galaxies, and other outer space objects.A large number of observatories have been launched into orbit, and most of them have greatly enhanced our knowledge of the cosmos.Performing astronomy from the Earth's surface is limited by the filtering and distortion of electromagnetic radiation due to the Earth's atmosphere.

This makes it desirable to place astrononomical observation devices into space.As a telescope orbits the Earth outside the atmosphere it is subject neither to twinkling (distortion due to thermal turbulences of the air) nor to light pollution from artificial light sources on the Earth.

But space-based astronomy is even more important for frequency ranges which are outside of the optic window and the radio window, the only two wavelength ranges of the electromagnetic spectrum that are not severely attenuated by the atmosphere.

For example, X-ray astronomy is nearly impossible when done from the Earth, and has reached its current important stand within astronomy only due to orbiting satellites with X-ray telescopes such as the Chandra observatory or XMM-Newton observatory.

Infrared and ultraviolet are also greatly blocked.







Compton Gamma Ray Observatory



The Compton Gamma Ray Observatory (CGRO) was the second of the NASA "Great Observatories" to be launched to space, following the Hubble Space Telescope.The observatory was launched on the Space Shuttle Atlantis, mission STS-37, on 5 April 1991.It was deployed in low earth orbit at 450 km in order to avoid the Van Allen radiation belt.It was the heaviest astrophysical payload ever flown at that time, at 17000 kg. The CGRO is part of NASA's Great Observatories series, with the Hubble Space Telescope, the Chandra X-ray Observatory, and the Spitzer Space Telescope.

See also

References

External links



Arip Nurahman

Guru dan Dosen Profesional

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