The Elegant Universe I

The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory
Author(s)	Brian Greene
Subject(s)	String theory
Genre(s)	Non-fiction
Publisher	Vintage
Publication date	February 1999
Media type	Print (Hardcover andPaperback)
Pages	464
ISBN	0-375-70811-1
Followed by	The Fabric of the Cosmos: Space, Time, and the Texture of Reality

The Elegant Universe is a book by Brian Greene published in 1999 which introduces string theoryand provides a comprehensive though non-technical assessment of the theory and some of its shortcomings.

Contents

Beginning with a brief consideration of classical physics, which concentrates on the major conflicts in physics, Greene establishes a historical context for string theory as a necessary means of integrating the probabilistic world of the standard model of particle physics and the deterministicNewtonian physics of the macroscopic world. Greene discusses the essential problem facing modern physics: unification of Albert Einstein's theory of General Relativity and Quantum Mechanics. Greene suggests that string theory is the solution to these two conflicting approaches. Greene frequently uses analogies and thought experiments to provide a means for the layman to come to terms with the theory which has the potential to create a unified theory of physics.

Aouthor

Brian Greene (born February 9, 1963) is an American theoretical physicist and string theorist. He has been a professor at Columbia University since 1996. Greene has worked on mirror symmetry, relating two different Calabi-Yau manifolds (concretely, relating theconifold to one of its orbifolds). He also described the flop transition, a mild form oftopology change, showing that topology in string theory can change at the conifold point. He has become known to a wider audience through his books for the general public, The Elegant Universe, Icarus at the Edge of Time, The Fabric of the Cosmos, The Hidden Reality, and a related PBS television special. Greene also appeared on The Big Bang Theory episode "The Herb Garden Germination."

Biography

Greene was born in New York City. His father, Alan Greene, was a one-time vaudevilleperformer and high school dropout who later worked as a voice coach and composer. After attending Stuyvesant High School, where he was a classmate of Lisa Randall, Greene entered Harvard in 1980 to major in physics. 

After completing his bachelor's degree, Greene earned his doctorate from Oxford University as a Rhodes Scholar, graduating in 1987. While at Oxford, Greene also studied piano with the concert pianist Jack Gibbons.

Greene joined the physics faculty of Cornell University in 1990, and was appointed to a full professorship in 1995. The following year, he joined the staff of Columbia Universityas a full professor. 

At Columbia, Greene is co-director of the university's Institute for Strings, Cosmology, and Astroparticle Physics (ISCAP), and is leading a research program applying superstring theory to cosmological questions. He is also one of the FQXi large grant awardees, his project title being "Arrow of Time in the Quantum Universe". 

His co-investigators are David Albert and Maulik Parikh.

Greene is married to former ABC producer Tracy Day. He became vegan in 1997 after touring Farm Sanctuary in Watkins Glen, NY.

Brian Greene
At the launch of the World Science Festival, April 2008
Born	February 9, 1963 (age 48) New York City, U.S.
Residence	United States
Nationality	USA
Fields	Physics
Institutions	Cornell University Columbia University
Alma mater	Stuyvesant High School Harvard University Oxford University
Doctoral advisor	Graham G. Ross (Oxford University) James Binney
Known for	String theory The Elegant Universe The Fabric of the Cosmos

Research

Greene's area of research is string theory, a candidate for a theory of quantum gravity, attempts to explain the different particle species of thestandard model of particle physics as different aspects of a single type of one-dimensional, vibrating string. One peculiarity of string theory is that it postulates the existence of extra dimensions of space – instead of the usual four dimensions, there must be ten spatial dimensions and one dimension of time to allow for a consistently defined string theory. The theory has several explanations to offer for why we do not perceive these extra dimensions, one being that they are "curled up" (compactified, to use the technical term) and are hence too small to be readily noticeable.

In the field, Greene is best known for his contribution to the understanding of the different shapes the curled-up dimensions of string theory take on. The most important of these shapes are so-called Calabi-Yau manifolds; when the extra dimensions take on those particular form, physics in three dimensions exhibits an abstract symmetry known as supersymmetry.

Greene has worked on a particular class of symmetry relating two different Calabi-Yau manifolds, known as mirror symmetry (concretely, relating the conifold to one of its orbifolds). He is also known for his research on the flop transition, a mild form of topology change, showing that topology in string theory can change at the conifold point.

Currently, Greene studies string cosmology, especially the imprints of trans Planckian physics on the cosmic microwave background, andbrane-gas cosmologies that could explain why the space around us has three large dimensions, expanding on the suggestion of a black hole electron, namely that the electron may be a black hole.

See also

• List of physicists
• List of theoretical physicists
• String Theory
• Theory of everything
• Unified Field Theory

References

1. ^ "Biography for Brian Greene". Internet Movie Database. Retrieved 2007-10-31.
2. ^ JR Minkel (Spring 2006). "The String is The Thing - Brian Greene Unravels the Fabric of the Universe". Columbia Magazine (Columbia University). Retrieved 2007-10-31.
3. ^ ^a b Overbye, Dennis (June 3, 2008). "An Overflowing Five-Day Banquet of Science and Its Meanings". New York Times.
4. ^ Boss, Shira. "Brian Greene Has the World on a String". Columbia College Today. Retrieved 16 January 2011.
5. ^ "Consciousness Emerges in the Ash of Stellar Alchemy". Flickr. Retrieved 2011-03-22.
6. ^ Was brian greene vegan
7. ^ "Profile of Brian Greene". Royce Carlton Incorporated. Archived from the original on 2007-08-23. Retrieved 2008-02-17.
8. ^ Amazon.com's catalog entry
9. ^ Shapiro, Gary. "New York, Cambridge To Host Citywide Science Festivals". New York Sun. Retrieved 2007-02-25.
10. ^ "Future-ish Honor". 2010. Retrieved 2010-02-15.

Inflation in Cosmology

In physical cosmology, cosmic inflation, cosmological inflation or just inflation is the theorized extremely rapid exponential expansion of the early universe by a factor of at least 10⁷⁸ in volume, driven by a negative-pressure vacuum energy density. The inflationary epoch comprises the first part of the electroweak epoch following the grand unification epoch. It lasted from 10⁻³⁶ seconds after the Big Bang to sometime between 10⁻³³ and 10⁻³² seconds. Following the inflationary period, the universe continued to expand, but at a slower rate.

The term "inflation" is also used to refer to the hypothesis that inflation occurred, to the theory of inflation, or to the inflationary epoch. The inflationary hypothesis was originally proposed in 1980 by American physicist Alan Guth, who named it "inflation". It was also proposed by Katsuhiko Sato in 1981.

As a direct consequence of this expansion, all of the observable universe originated in a small causally connected region. Inflation answers the classic conundrum of the Big Bang cosmology: why does the universe appear flat, homogeneous, and isotropic in accordance with the cosmological principle when one would expect, on the basis of the physics of the Big Bang, a highly curved, heterogeneous universe? Inflation also explains the origin of the large-scale structure of the cosmos. Quantum fluctuations in the microscopic inflationary region, magnified to cosmic size, become the seeds for the growth of structure in the universe (see galaxy formation and evolution and structure formation).

While the detailed particle physics mechanism responsible for inflation is not known, the basic picture makes a number of predictions that have been confirmed by observation. Inflation is thus now considered part of the standard hot Big Bang cosmology. The hypothetical particle or field thought to be responsible for inflation is called the inflaton.

Source: http://en.wikipedia.org/wiki/Inflation_%28cosmology%29

Mengenal Alam Semesta

The universe is the totality of existence, including planets, stars, galaxies, the contents of intergalactic space, and all matter and energy. Definitions and usage vary and similar terms include the cosmos, the world and nature. Scientific observation of earlier stages in the development of the universe, which can be seen at great distances, suggests that the universe has been governed by the same physical laws and constants throughout most of its extent and history. The universe is believed to be at least 93 billion light years in diameter and has existed for about 13.7 billion years, since it was created by the Big Bang.

There are various multiverse hypotheses, in which physicists have suggested that the universe might be one among many universes that likewise exist. The farthest distance that it is theoretically possible for humans to see is described as the observable universe. Observations have shown that the universe appears to be expanding at an accelerating rate, and a number of models have arisen to predict its ultimate fate.

History

 

 

Observational history

Throughout recorded history, several cosmologies and cosmogonies have been proposed to account for observations of the universe. The earliest quantitative geocentric models were developed by the ancient Greek philosophers. Over the centuries, more precise observations and improved theories of gravity led to Copernicus's heliocentric model and the Newtonian model of the Solar System, respectively. Further improvements in astronomy led to the realization that the Solar System is embedded in a galaxy composed of billions of stars, the Milky Way, and that other galaxies exist outside it, as far as astronomical instruments can reach. Careful studies of the distribution of these galaxies and their spectral lines have led to much of modern cosmology. Discovery of the red shift and cosmic microwave background radiation revealed that the universe is expanding and apparently had a beginning.

History of the universe

According to the prevailing scientific model of the universe, known as the Big Bang, the universe expanded from an extremely hot, dense phase called the Planck epoch, in which all the matter and energy of the observable universe was concentrated. Since the Planck epoch, the universe has been expanding to its present form, possibly with a brief period (less than 10⁻³² seconds) of cosmic inflation. Several independent experimental measurements support this theoretical expansion and, more generally, the Big Bang theory. Recent observations indicate that this expansion is accelerating because of dark energy, and that most of the matter in the universe may be in a form which cannot be detected by present instruments, called dark matter. The common use of the "dark matter" and "dark energy" placeholder names for the unknown entities purported to account for about 95% of the mass-energy density of the universe demonstrates the present observational and conceptual shortcomings and uncertainties concerning the nature and ultimate fate of the universe.

Current interpretations of astronomical observations indicate that the age of the universe is 13.75 ± 0.17 billion years,(whereas the decoupling of light and matter, see CMBR, happened already 380,000 years after the Big Bang), and that the diameter of the observable universe is at least 93 billion light years or 8.80×10²⁶ metres. According to general relativity, space can expand faster than the speed of light, although we can view only a small portion of the universe due to the limitation imposed by light speed. Since we cannot observe space beyond the limitations of light (or any electromagnetic radiation), it is uncertain whether the size of the universe is finite or infinite.

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