In string theory one studies strings moving in a fixed classical spacetime. ...what we call a background-dependent approach. ...One of the fundamental discoveries of Einstein is that there is no fixed background. The very geometry of space and time is a dynamical system that evolves in time. The experimental observations that energy leaks from binary pulsars in the form of gravitational waves-at the rate predicted by general relativity to the... accuracy of eleven decimal places-tell us that there is no more a fixed background of spacetime geometry than there are fixed crystal spheres holding the planets up.
Lee SmolinRelated topics
accuracy approach background binary call classical crystal decimal eleven energy experimental form fundamental general geometry holding moving rate relativity space string studies system theory time einstein spacetime stringsRelated quotes
The BEH mechanism operates within the context of gauge theories. Despite the fact that grand unification schemes reach scales comparable to the Planck scale, there was, a priori, no indication that Yang-Mills fields offer any insight into quantum gravity. The only approach to quantum gravity that had some success, in particular in the context of a quantum interpretation of the black hole entropies, are the superstring theory approaches and the possible merging of the five perturbative approaches (Type IIA, IIB, Type I and the two heterotic strings) into an elusive M-theory whose classical limit would be 11-dimensional supergravity.
Francois Englert
There are certain devices that one uses in Romantic music that are appropriate only for Romantic or subsequent music. If you take those devices and apply them to earlier music, then it's totally inappropriate, and it makes the Classical music sound silly. However, if you were to use what you might call ‘Classical devices' on Romantic music, historically, that would be correct! It very often benefits Romantic music, which is sometimes rather disjunctive, rather shapeless in comparison with Classical symphonic or sonata form. Romantic music very often benefits from that tighter organization that you get from Classical music.
Leon Fleisher
The following work is not a republication of a former treatise by the Author, entitled, "The Mathematical Analysis of Logic." Its earlier portion is indeed devoted to the same object, and it begins by establishing the same system of fundamental laws, but its methods are more general, and its range of applications far wider. It exhibits the results, matured by some years of study and reflection, of a principle of investigation relating to the intellectual operations, the previous exposition of which was written within a few weeks after its idea had been conceived.
George Boole
I suppose men are born with traits that can be cultivated in the direction of leadership. But there is also no doubt that leadership can be cultivated. The idea of any man being born an army commander or being born to be a theater commander, such as General Eisenhower, just isn't so. The characteristics of leadership, necessarily has to have certain decisiveness and confidence come from knowledge based on studies and training. The fundamental thing is your basic knowledge, the development of your mind and your ability to apply this knowledge as you go along your military career.
Lucian Truscott
Capital, explaining the origins of the capitalist mode of production, points towards the inevitable historical decline and fall of this same social system. An economic theory based upon the historical relativity of every economic system, its strict limitation in time, tactlessly reminds Messrs the capitalists, their hangers-on and their apologists that capitalism itself is a product of history. It will perish in due course as it once was born. A new social form of economic organization will then take the place of the capitalist one: it will function according to other laws than those which govern the capitalist economy.
Ernest Mandel
