PURPOSE: To model the formation of Cosmic Strings.
DESCRIPTION: Topological defects which cause symmetry breaking are shown. This is a model for the symmetry beraking which forms monopoles and cosmic strings.
This device is a ferromagnetic garnet demonstration. It is viewed with a video camera. The device uses polarized light and the Faraday Effect to view the magnetization of domains in a ferromagnetic garnet, which has the property of rotating the plane of polarization of the light by an angle dependent on its magnetization. Magnetic domain structure in the garnet is viewed as shown in the photograph. When the magnetic field is increased the domain alignment becomes more complete and the lines vanish and leave a "magnetic bubble," which is a small group of domains aligned opposite the domains of the surrounding area.
EQUIPMENT: Mounted magnetic domain demonstrator, TV microscope gizmo, lamp with lens, power supply with polarity switch.
SETUP TIME: 20 min. Note that there is a front side to the magnetic domains apparatus. The front side must be facing the camera otherwise the image of the domains is not clearly visible. See below.
Updated by JZ in 1/03/2005