It would be intellectually satisfying if all forces derive from a single principle, but more importantly, that principle would reveal the conservation laws that give rise to matter itself.
Perhaps electroweak unification is only the first step. Since the particle discovered last year seems to be the long-sought Higgs boson, we may finally be able to test this theory. It is thus impossible to do a truly isolated experiment. This idea is that we are immersed in a field that interacts with Z bosons, giving them an effective mass. The Higgs mechanism is one possible explanation. Since electric and weak charges do exist, it is widely believed that the laws of physics have electroweak symmetry, but something in the environment "breaks" the symmetry. If the symmetry were exact, they would both be massless. However, the photon is massless and the Z boson is so massive that only a handful of high-energy accelerators have ever created them. A photon can behave like a Z boson and vice-versa, under the right circumstances. An experimental consequence of this is that the photons of electromagnetism and the Z bosons of the weak force are really the same particle (or half-and-half mixtures of two fundamental particles, depending on how you want to look at it). The gauge symmetry of the weak force is much more complex than that of electromagnetism, but the two are actually factors of a single equation. In the 1970s and '80s, physicists discovered that the weak force can also be added to the mix. When magnetism is added to the mix, gauge symmetry becomes more complicated, since you can trade electric voltages for magnetic potentials. A circuit operating between 0 volts and 5 volts is the same as the circuit between 100 volts and 105 volts. It is called gauge symmetry, and, if you're familiar with electronics, this is the reason that all voltages are measured relative to an arbitrary ground level. Similarly, the conservation of electric charge is due to a symmetry. Since mass is a form of energy, this fact about the nature of time implies that matter is persistent and may be thought of as a substance. For instance, the fact that an isolated experiment performed today would yield the same result as the same experiment performed tomorrow-time translation symmetry-is ultimately responsible for the conservation of energy. Perhaps the deepest idea in physics is Noether's Theorem, which states that symmetries in the laws of physics imply the existence of conserved quantities.
It's already clear that two of them, electromagnetism and the weak force, are related by a unifying principle, known as electroweak symmetry. Many physicists are motivated by the idea that they are really four manifestations of a single principle, yet to be discovered. However, these four forces are not truly distinct.
#Particle playground unity series
In this series of Physics in a Nutshell articles, Don and I have talked about each of the four fundamental forces of nature: electromagnetism, the strong force, the weak force and gravity. Send comments and suggestions the FermilabĪpart from mass, the electromagnetic photon and the weak Z boson are the same particle-in two manifestations.
Haricots verts with red peppers and almonds Beef en croute with coriander walnut filling Breakfast: blueberry-stuffed French toast Ongoing and upcoming conferences at Fermilab THERE WILL BE NO ACCELERATOR PHYSICS AND TECHNOLOGYĪ weekly calendar with links to additional information. Title: Constraining Cosmology and Dark Energy Models with Current and Future Wide-Field Imaging Surveys Speaker: Tim Eifler, University of Pennsylvania Particle Astrophysics Seminar (NOTE DATE, TIME, LOCATION) - WH6NW Title: Dark Matter Inspired Exotics Searches with ATLAS
Speaker: Ben Brau, University of Massachusetts, Amherst Joint Experimental-Theoretical Physics Seminar - One West Title: Closing the Door on Weak-Scale SUSY Speaker: Natalia Toro, Perimeter Institute LHC Physics Center Topic of the Week Seminar - WH11NE
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