Surprisingly, they all are related to each other, and to one additional theory-not quite a string theory-known as M-theory. One of the important achievements of string duality has been the determination of the behavior of all of the various consistent string theories (there are five of them) when the interactions become strong. Lessons learned from the history of particle physics suggest that this should be a signal of new physics occurring at these tiny distance scales. A serious problem arises when general relativity is extrapolated to tiny distance scales (again roughly 10 − 32 cm) where quantum effects must be taken into account: the quantum-mechanical perturbation expansion of this theory has uncontrollable divergences. General relativity is a “classical” theory, which takes no notice of effects from quantum mechanics (whose development was another of the triumphs of theoretical and experimental physics in the early part of the century). Incorporating gravity into this framework required an even more drastic modification of our view of space and time: in general relativity, space time is seen as intrinsically warped, and the warping is responsible for the gravitational force. Reconciling the Newtonian theory of motion with the experimentally observed constancy of the speed of light required the introduction of special relativity, which quite remarkably insists that space and time are intimately related, much as different faces of the same coin. The study of motion and gravity also has undergone several revisions during this century. The standard model is valid to distances as small as 10 − 16 cm, and there is some evidence (such as that obtained by extrapolating the strengths of the four forces to determine the distance scale at which they might become indistinguishable) that the next level of structure will be detected only at a distance scale of roughly 10 − 32 cm, far beyond our abilities to measure in the laboratory. The current “standard model” of particle physics-which is nearly 25 years old, has much experimental evidence in its favor and is comprised of six quarks, six leptons, four forces, and the as yet unobserved Higgs boson-contains internal indications that it, too, may be just another step along the path toward uncovering the truly fundamental degrees of freedom. Finally, the bibliography gives the sources for the information used in our analyses.Particle physicists have spent much of this century grappling with one basic question in various forms: what are the fundamental degrees of freedom needed to describe nature, and what are the laws that govern their dynamics? First molecules, then atoms, then “elementary particles” such as protons and neutrons all have been revealed to be composite objects whose constituents could be studied as more fundamental degrees of freedom. We also provide summaries of major actors and a glossary of key terms for reference. In Networks in the Public Sphere, we look at how the controversy has spilled over into blogs, websites and popular books. We then move on to analyze networks in the scientific community to gain some perspective on how string theory research is conducted. ![]() The history page provides a timeline of significant events in the development of the theory, as well as data on the size and geographic distribution of string theory research over time. In this site, we take a specific scientometric prospective. The ApproachĪs this controversy has been ongoing for many years, there is a very large amount of information available, and therefore many possible ways of analyzing the debate. In this site, we present an analysis of this controversy, and thereby learn some general facts about how science is conducted. Critics, however, point out that string theory has not yet made any experimental predictions. Supporters of the theory allege that it has brought physics closer to finding a single theory of everything, and that the string paradigm will eventually prove itself to be the correct one. Although the theory has been in development for nearly 40 years, it is still not a universally accepted physical paradigm. The picture on the right shows an artists rendition of these strings. ![]() ![]() To do so, it proposes that all particles are composed of extremely small vibrating strings, and that the universe contains small, hidden extra dimensions. ![]() String theory is an area of research in theoretical physics that seeks to unite quantum mechanics - our current theory of very small objects - with general relativity - our current theory of very large objects. The String Theory Debate What Is String Theory?
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