Replacing particles by strings is a naive-sounding step, from which many other things follow. In fact, replacing Feynman graphs by Riemann surfaces has numerous consequences: 1. It eliminates the infinities from the theory. ...2. It greatly reduces the number of possible theories. ...3. It gives the first hint that string theory will change our notions of spacetime. Just as in QCD, so also in gravity, many of the interesting questions cannot be answered in perturbation theory. In string theory, to understand the nature of the Big Bang, or the quantum fate of a black hole, or the nature of the vacuum state that determines the properties of the elementary particles, requires information beyond perturbation theory... Perturbation theory is not everything. It is just the way the [string] theory was discovered.
 
    
        Edward Witten 
     
    
     
    Related topics 
            beyond 
            black 
            change 
            elementary 
            everything 
            fate 
            follow 
            gives 
            hole 
            nature 
            number 
            perturbation 
            possible 
            quantum 
            state 
            step 
            string 
            way 
            things 
            Riemann 
            replacing 
            Feynman 
            questions 
            spacetime 
        
    
                    Related quotes 
        
                    
                                        
                    
    
        As the natural sciences have developed to encompass increasingly complex systems, scientific rationality has become ever more statistical, or probabilistic. The deterministic classical mechanics of the enlightenment was revolutionized by the near-equilibrium statistical mechanics of late 19th century atomists, by quantum mechanics in the early 20th century, and by the far-from-equilibrium complexity theorists of the later 20th century. Mathematical neo-Darwinism, information theory, and quantitative social sciences compounded the trend. Forces, objects, and natural types were progressively dissolved into statistical distributions: heterogeneous clouds, entropy deviations, wave functions, gene frequencies, noise-signal ratios and redundancies, dissipative structures, and complex systems at the edge of chaos. 
         
 
    Nick Land 
 
                 
            
        
     
    
    
                                        
                    
    
        Every development of truths which relate to human nature, and more especially its active manifestations, is attended with a wish to see worked out in practice what theory has shown us to be just and good. To man, whose mind is seldom satisfied with the calmly beneficent influence of abstract ideas, this desire is perfectly natural, and it increases in liveliness with the spirit of benevolent sympathy in social happiness and well-being. But, however natural in itself, and however noble in its origin, this desire has not unfrequently led to hurtful consequences,-nay, often to greater evils than the colder indifference, or (as from the very opposite cause the same effect may follow) the glowing enthusiasm, which, comparatively heedless of reality, delights only in the pure beauty of ideas. 
         
 
    Wilhelm von Humboldt 
 
                 
            
        
     
    
    
    
    
                                        
                    
    
        P. Bernays has pointed out on several occasions that, since the consistency of a system cannot be proved using means of proof weaker than those of the system itself, it is necessary to go beyond the framework of what is, in Hilbert's sense, finitary mathematics if one wants to prove the consistency of classical mathematics, or even that of classical number theory. Consequently, since finitary mathematics is defined as the mathematics in which evidence rests on what is intuitive, certain abstract notions are required for the proof of the consistency of number theory.... In the absence of a precise notion of what it means to be evident, either in the intuitive or in the abstract realm, we have no strict proof of Bernays' assertion; practically speaking, however, there can be no doubt that it is correct... 
         
 
    Paul Bernays