article: Physicists hope it could lead to discoveries that could potentially represent the biggest revolution in physics since Einstein's theories of relativity. Among them is Prof Jordan Nash from Imperial College London, who is working on the CMS experiment at the LHC. "We are opening a new window on the Universe and looking forward to seeing what's there," he said. "As much as we have a lot of theories of what might be out there we don't know. We'd love to find something completely unexpected and we might, and that's the exciting bit." They want a glimpse into a world never seen before. By smashing atoms harder than they have been smashed before physicists hope to peel back another veil of reality. The aim of the various theories of physics is to explain how the Universe was formed and how the bits that make it up work. One of the most successful of these theories is called the "Standard Model". It explains how the world of the very, very small works. Just as the world became very strange when Alice shrunk after drinking a potion in the children's book Alice's Adventures in Wonderland, physicists have found things are quite different when they study the goings on at scales that are even smaller than the size of an atom. By doubling the energy of the LHC, it will enable them to discover new characters in the wonderful and mysterious tale of how the Universe works and came to be. The Standard Model describes how the basic building blocks that make up atoms and the forces of nature interact. And just as in Alice's stories it features some eccentric characters, notably a family of 17 elementary particles. Some are familiar from school physics lessons, household names if you like. One of the best known in the sub-atomic world is perhaps the electron, which orbits the atom and is involved in electricity and magnetism. Another flashy A-lister is the photon, which is a particle of light. But most particles from the Standard Model family are more niche, a little more art house if you like, and have strange names. In fact, one of them is actually called "the strange quark". And others from this group of particles are named as if by thoughtless and unimaginative parents: "up", "down", "top" and "bottom" though "charm" does sound a little more, well, charming. A couple of these combine in various ways to form protons and neutrons, which along with electrons make up atoms from which the world is made. These are all members of a group called "fermions". And there is another group called the "bosons", that quite literally hold the place together. They are called the "force carriers" in physics text books and give rise to the forces of nature: electrical, magnetic and nuclear forces, which pull other particles together or push them apart. With the discovery of the sub-atomic world's biggest celeb of all, the Higgs boson, scientists have now detected all the particles predicted by the Standard Model: a theory that beautifully explains how the Universe
summary: The Large Hadron Collider (LHC) has been restarted after a two-year shutdown.