ATLAS Experiment Home The Large Hadron Collider The Large Hadron Collider (LHC) is the world’s largest and most powerful particle accelerator. It first started up on 10 September 2008, and remains the latest addition to CERN’s accelerator complex. The LHC consists of a 27-kilometre ring of superconducting magnets with a number of accelerating structures to boost the energy of the particles along the way. Inside the accelerator, two high-energy particle beams travel at close to the speed of light before they are made to collide. The beams travel in opposite directions in separate beam pipes – two tubes kept at ultrahigh vacuum. They are guided around the accelerator ring by a strong magnetic field maintained by superconducting electromagnets. Thousands of magnets of different varieties and sizes are used to direct the beams around the accelerator. All the controls for the accelerator, its services and technical infrastructure are housed under one roof at the CERN Control Centre. How many kilometres of cables are there on the LHC?
Giant natural particle accelerator discovered above thun (PhysOrg.com) -- A lightning researcher at the University of Bath has discovered that during thunderstorms, giant natural particle accelerators can form 40 km above the surface of the Earth. Dr Martin Füllekrug from the University’s Department of Electronic & Electrical Engineering presented his new work on Wednesday 14 April at the Royal Astronomical Society National Astronomy Meeting (RAS NAM 2010) in Glasgow. His findings show that when particularly intense lightning discharges in thunderstorms coincide with high-energy particles coming in from space (cosmic rays), nature provides the right conditions to form a giant particle accelerator above the thunderclouds. The cosmic rays strip off electrons from air molecules and these electrons are accelerated upwards by the electric field of the lightning discharge. The free electrons and the lightning electric field then make up a natural particle accelerator. Explore further: Remnants of Tropical Depression Peipah still raining on Philippines
M-theory M-theory is a theory in physics that unifies all consistent versions of superstring theory. The existence of such a theory was first conjectured by Edward Witten at the string theory conference at the University of Southern California in the summer of 1995. Witten's announcement initiated a flurry of research activity known as the second superstring revolution. Background[edit] Quantum gravity and strings[edit] One of the deepest problems in modern physics is the problem of quantum gravity. Number of dimensions[edit] In everyday life, there are three familiar dimensions of space (up/down, left/right, and forward/backward), and there is one dimension of time (later/earlier). Despite the obvious relevance of four-dimensional spacetime for describing the physical world, there are several reasons why physicists often consider theories in other dimensions. Dualities[edit] Main articles: S-duality and T-duality A diagram of string theory dualities. and winding number in the dual description. .
Introduction to M-theory In non-technical terms, M-theory presents an idea about the basic substance of the universe. Background[edit] In the early years of the 20th century, the atom – long believed to be the smallest building-block of matter – was proven to consist of even smaller components called protons, neutrons and electrons, which are known as subatomic particles. Beginning in the 1960s, other subatomic particles were discovered. In the 1980s, a new mathematical model of theoretical physics called string theory emerged. These "strings" vibrate in multiple dimensions, and depending on how they vibrate, they might be seen in three-dimensional space as matter, light, or gravity. String theory, as mentioned above, ran into a problem: another version of the equations was discovered, then another, and then another. Status[edit] M-theory is not complete, but the underlying structure of the mathematics has been established and is in agreement with all the string theories. See also[edit] Superstring theory
Bosonic string theory Bosonic string theory is the original version of string theory, developed in the late 1960s. In the early 2000s, supersymmetry was discovered in the context of string theory, and a new version of string theory called superstring theory (supersymmetric string theory) became the real focus. Nevertheless, bosonic string theory remains a very useful "toy model" to understand many general features of perturbative string theory, and string theory textbooks usually start with the bosonic string. The first volume of Polchinski's String Theory and Zwiebach's A First Course in String Theory are good examples. Problems[edit] Although bosonic string theory has many attractive features, it falls short as a viable physical model in two significant areas and is forced to posit a 26 dimensional spacetime to remedy inconsistencies. First, it predicts only the existence of bosons whereas many physical particles are fermions. Mathematics[edit] See also[edit] References[edit] External links[edit]
The Physics behind the paper behind “Colliding Particles” « Life This post also at The Guardian. This is a bit of a niche post but there was recently a review in Physics World of these videos I’m in about research at the Large Hadron Collider (LHC). While generally positive, the review pointed out that although the videos are partially based around a particular scientific paper about how one might find the Higgs boson (referred to in the films as the “Eurostar paper”), they don’t really explain the physics behind it, being focussed more on “how science works” than a specific result. Fair comment. So here is my attempt to explain the physics behind this paper to an intelligent but non-specialist audience. I’ll concentrate on explaining the new ideas in the paper rather than giving a summary of why the Higgs is interesting or what the LHC is. about that at the end of this article for the BBC, and might try again at some point. Now you see it, now you don’t For a 120 GeV Higgs, the heaviest thing it can decay to is a pair of bottom (b) quarks. Fast movers