Q: When did light pollution become a problem?
A: Light pollution started to become a problem in the early 20th century, around the time cities began adopting electric lighting.
Q: Are modern telescopes that observe alternate wavelengths of light affected?
A: Yes, and no. This web site was designed to focus on visible light pollution, so in that aspect, radio telescopes are not affected. If I were to talk about all forms of light pollution, then the answer would be yes. Observatories that have radio telescopes have to be careful about TV, radio, and cell phone towers are, because they emit radio light.
Q: What can I do about it?
A:The easiest way to reduce the amount of light pollution you are creating is to just turn off any lights that are not needed. For example, if you have a security light outside, instead of having it on constantly, think about adding an infrared detector, that way the light will be on when you need it. Another way to reduce light pollution is to make sure that the light is only illuminating what needs to be illuminated. Putting a shade on a lamp would be an example. Florescent, low-pressure sodium, and high-pressure sodium light bulbs are the best light bulbs to use to reduce light pollution due to the fact that they emit light in one wavelength, making it easier to filter out man made light pollution.
Q: Does light pollution affect anything else beside the visibility of stars?
A: Yes, it does. Most electric energy is generated by thermal power stations, most of which use fossilized fuel. The more light that is wasted, the more energy is needed, thus it causes more air pollution.