The optics table is where the equipment is placed to perform an experiment. In an actual laboratory, an optics table is used to isolate the experiment from the vibrations of the building. Shown in the figure are ten spotlights where a selected piece of equipment is allowed to be placed on the table. As each piece of equipment is selected from the stockroom counter, the spotlights will show where the selected item can be placed. Sources can be placed in positions 1, 2, or 3; samples can only be placed in position 5; detectors can be placed in positions 1, 3, 4, 5, 8, 9, or 10; the electric and magnetic field modifiers can be placed together or individually in position 5 (when a sample is present) or in position 7 (alone); and the heat modifier can only be placed at position 5 when a sample is present.