The diameter of our disk-shaped galaxy, the milky way, is about 1.0 x 10^5 light-years (ly). the distance to the andromeda galaxy, which is the spiral galaxy nearest to the milky way, is about 2.0 million ly. if a scale model represents the milky way and andromeda galaxies as dinner plates 25 cm in diameter, determine the distance between the centers of the two plates.

Select light for the type of wave, adjust the wavelength so that the light is red, and increase the amplitude of the light to the max. then, select the start button at the source location to begin producing the waves. light is a form of electromagnetic wave, containing oscillating electric and magnetic fields. the wave amplitude detector mentioned above shows how the electric field oscillates in time at the location of the probe. the amplitude of the wave at the location of the probe is equal to the maximum electric field measured. how does the amplitude of the wave depend on the distance from the source?