Expanding Universe: Materials

Below is a plot showing what the spectrum of a real galaxy might look like. Spectra like this can be measured with telescopes like Berkeley's Keck Telescope (the largest optical telescope in the world, it's mirror is over 10 meters across!). This spectrum is exactly like the rainbows you saw earlier with the spectrograph, but instead of showing the colors we have plotted the intensity of each wavelength (color). This means that the lines you saw before are represented by spikes on the plot.