Читать книгу String Theory For Dummies - Andrew Zimmerman Jones - Страница 90

A change in location or position that retains the properties of the system is called a geometric symmetry (or sometimes translational symmetry). Another form of symmetry is an internal symmetry, which is when something within the system can be swapped for something else and the system (as a whole) doesn’t change. When a symmetrical situation at high energy collapses into a lower energy ground state that is asymmetrical, it’s called spontaneous symmetry breaking. An example would be when a roulette wheel spins and slows into a “ground state.” The ball ultimately settles into one slot in the wheel — and the gambler either wins or loses.

String theory goes beyond the symmetries we observe to predict even more symmetries that aren’t observed in nature. It predicts a necessary symmetry that’s not observed in nature called supersymmetry. At the energies we observe, supersymmetry is an example of a broken symmetry, though physicists believe that in high-energy situations, supersymmetry would no longer be broken (which is what makes it so interesting to study). We cover supersymmetry in Chapters 2 and 10.