background preloader

String theory

String theory
String theory was first studied in the late 1960s[3] as a theory of the strong nuclear force before being abandoned in favor of the theory of quantum chromodynamics. Subsequently, it was realized that the very properties that made string theory unsuitable as a theory of nuclear physics made it a promising candidate for a quantum theory of gravity. Five consistent versions of string theory were developed until it was realized in the mid-1990s that they were different limits of a conjectured single 11-dimensional theory now known as M-theory.[4] Many theoretical physicists, including Stephen Hawking, Edward Witten and Juan Maldacena, believe that string theory is a step towards the correct fundamental description of nature: it accommodates a consistent combination of quantum field theory and general relativity, agrees with insights in quantum gravity (such as the holographic principle and black hole thermodynamics) and has passed many non-trivial checks of its internal consistency.

http://en.wikipedia.org/wiki/String_theory

Car Lease Takeover - Lease Transfer - How does it work? What is a car lease takeover or lease transfer? How does it work? In a tough economy, automotive consumers look for affordable ways to drive the cars they need and want. Lease takeovers, or lease transfers, are increasingly providing the ideal answer for many of these consumers. Although lease transfers have been around for years, it has now become the hottest new way to acquire a late model automobile at the lowest possible cost. Here's how a car lease takeover works Someone who is currently leasing a car wants out of their lease. Loop quantum gravity More precisely, space can be viewed as an extremely fine fabric or network "woven" of finite loops. These networks of loops are called spin networks. The evolution of a spin network over time is called a spin foam. The predicted size of this structure is the Planck length, which is approximately 10−35 meters. According to the theory, there is no meaning to distance at scales smaller than the Planck scale.

Dark matter Dark matter is invisible. Based on the effect of gravitational lensing, a ring of dark matter has been detected in this image of a galaxy cluster (CL0024+17) and has been represented in blue.[1] Dark matter is a hypothetical kind of matter that cannot be seen with telescopes but accounts for most of the matter in the universe. The existence and properties of dark matter are inferred from its gravitational effects on visible matter, radiation, and the large-scale structure of the universe. Other than neutrinos, a form of hot dark matter, it has not been detected directly, making it one of the greatest mysteries in modern astrophysics. Astrophysicists hypothesized dark matter because of discrepancies between the mass of large astronomical objects determined from their gravitational effects and the mass calculated from the observable matter (stars, gas, and dust) that they can be seen to contain.

Einstein for Everyone Einstein for Everyone Nullarbor Press 2007revisions 2008, 2010, 2011, 2012, 2013 Copyright 2007, 2008, 2010, 2011, 2012, 2013 John D. Norton Published by Nullarbor Press, 500 Fifth Avenue, Pittsburgh, Pennsylvania 15260 with offices in Liberty Ave., Pittsburgh, Pennsylvania, 15222 All Rights Reserved John D. String Theory: A Brief Overview General relativity and quantum mechanics take different approaches at looking at how the universe works. Many physicists feel that there must be a method that unites the two. One contender for such a universal theory is superstring theory, or string theory, for short. Merging with Siva, Chapter 13: Five Steps to Enlightenment Monday LESSON 85 Step One: Attention The grand old man of the East who ordained me, Jnanaguru Yoganathan, Yogaswami of Jaffna, used to say time and time again, "It was all finished long ago." It's finished already.

Black hole A black hole is defined as a region of spacetime from which gravity prevents anything, including light, from escaping.[1] The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole.[2] Around a black hole, there is a mathematically defined surface called an event horizon that marks the point of no return. The hole is called "black" because it absorbs all the light that hits the horizon, reflecting nothing, just like a perfect black body in thermodynamics.[3][4] Quantum field theory in curved spacetime predicts that event horizons emit radiation like a black body with a finite temperature. This temperature is inversely proportional to the mass of the black hole, making it difficult to observe this radiation for black holes of stellar mass or greater. Objects whose gravity fields are too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace. History General relativity

The Mayan Prophecy of 2012 Is 2012 going to be the "End of The World?" No, not in terms of the complete destruction of the Earth and some kind of annihilation scenario. 2012 is not bringing the end of the planet. When we contemplate the expression "end of the world" let us realize the term "world" can refer to a cycle; a period of time; a world age era. Therefore 2012 is signalling the completion of one World Age Cycle, transitting into an emerging New World Age to come. Engineering The American Engineers' Council for Professional Development (ECPD, the predecessor of ABET)[1] has defined "engineering" as: The creative application of scientific principles to design or develop structures, machines, apparatus, or manufacturing processes, or works utilizing them singly or in combination; or to construct or operate the same with full cognizance of their design; or to forecast their behavior under specific operating conditions; all as respects an intended function, economics of operation or safety to life and property.[2][3] One who practices engineering is called an engineer, and those licensed to do so may have more formal designations such as Professional Engineer, Designated Engineering Representative, Chartered Engineer, Incorporated Engineer, Ingenieur or European Engineer. History[edit] Engineering has existed since ancient times as humans devised fundamental inventions such as the pulley, lever, and wheel.

Through the Wormhole: How Does the Universe Work? With the help of massive machines called particle accelerators, scientists studied the subatomic realm and made discoveries about the forces that operate at that level. But the search for a comprehensive explanation still continues. In particular, physicists have sought to find a way to reconcile Einstein's model of space-time, which seems to work best when applied to big objects like stars and galaxies, and the theory of quantum mechanics, which offers an explanation of electromagnetic and nuclear forces that makes sense of reality at the tiniest level.

Related: