How do fundamental particles acquire mass?
Physicists have high hopes for Europe's giant new atom smasher—they want nothing less than to crack the code of the physical universe.
http://ngm.nationalgeographic.com/geopedia/Atom_Smashers
While protons and neutrons can be broken down into fundamental particles known as quarks and gluons, electrons are themselves fundamental—at least for now. It’s always possible that as physicists deepen their understanding of the universe and wield more powerful technology they will discover an even tinier unit underlying the universe. Fundamental particles make up not only matter but also antimatter (in the form of antiparticles) and the particles that carry forces between other particles (e.g., photons mediate the electromagnetic force; gluons mediate the strong force).
Physicists use particle accelerators not only to find the smallest building blocks of the universe but also to shed light on the biggest questions: What is the universe composed of? What laws govern it? How did it come to be?
String theory tries to unify physics by explaining all particles and forces as vibrations of one-dimensional strings; it also predicts that space has six or seven more dimensions than we know about. Strings are too small for current particle accelerators to detect, but physicists hope to find indirect evidence of their existence, such as superparticles, particles disappearing into other dimensions, or disturbances in the behavior of ordinary particles.
In the mid-1800s James Maxwell realized that electricity and magnetism were not separate phenomena but rather aspects of the same force: electromagnetism. In the 1970s the standard model of physics, which still reigns today, showed that the electromagnetic and weak forces combine to form the electroweak force. There are four fundamental forces of nature: electromagnetic, weak, strong, and gravitational. Many physicists wonder if the strong force and gravity can’t also be combined with the electroweak force to effect a unification of forces. This idea is known as the Grand Unification Theory, or GUT, and physicists hope particle accelerators will help them find evidence of unification.
