1. Suppose that intelligent life in other parts of the universe were able to perceive parts of the electromagnetic spectrum which are invisible to us. If such creatures used 1 to 2 meter radio waves, would they then be able to "see" our FM radio broadcasts? If they respond to radiation at those wavelengths, would you guess that these creatures were much larger or much smaller than us? Do you think they could they detect small objects, such as a penny?
2. Estimate the number of photons emitted per second by a 15 watt fluorescent lamp.
3. Which emits more photons per second: a 15 watt fluorescent lamp or a 15 watt incandescent bulb? [hint: which is warmer? What type of radiation do you associate with heat?]
4. Estimate the energy of the electronic transition seen in orange sodium vapor lamps.