This interactive activity adapted from the National Park Service describes how humans impact the environment by creating light pollution such as light trespass, glare, and sky glow. Learn how unnecessary light wastes energy, obscures the view of the night sky, and affects wildlife. In addition, explore possible solutions to save energy and minimize light pollution.
Most of us to depend on artificial lights in our daily routines—to light our homes and offices; to illuminate outdoor areas such as streets, sidewalks, parking lots, and sports stadiums; and even for electronic signs and billboards. Without lighting our world would be very dark after the Sun goes down.
In general, light will always travel in a straight line until it hits an object. For example, a globe light fixture—a transparent spherical light fixture—radiates light in all directions. Without an opaque top to block the light, this type of fixture not only illuminates the intended area (the ground) but also radiates light upwards and sideways. This misdirected light provides unnecessary illumination and creates light pollution.
Light pollution created by excessive and badly designed lighting has negative effects. For instance, one form of light pollution is light trespass; in this form of light pollution, unwanted light extends unnecessarily—or trespasses—into someone else's space. For example, when a neighbor's light shines into your bedroom and keeps you up at night, that light is trespassing in your room.
Another major form of light pollution is sky glow, the bright, glowing effect of light from well-populated areas seen in the night sky. Light that is badly directed, along with light that reflects off the ground and other surfaces, is scattered in all directions by particles in the atmosphere. The resulting sky glow creates many negative effects: it obscures the stars from view, it interferes with astronomy research, and it diminishes our appreciation of the night sky.
Light pollution also affects wildlife. For example, some birds navigate by using the stars but cannot do so if sky glow obscures their view. Newly-hatched sea turtles instinctually move from the sand to the ocean at night because the water and horizon are generally brighter than the sand dunes and surrounding plant-life. However, artificial lights in the area can confuse them.
In addition to creating light pollution that affects both humans and wildlife, excessive and badly directed lighting wastes energy. It takes a great deal of electricity to power all the lights in the world. Unnecessary lights, and lights that illuminate in directions that do not need artificial lighting (toward the sky, for example), are an inefficient use of electricity and contribute needlessly to the depletion of natural resources such as oil and coal. They also contribute to the build-up of greenhouse gases in the atmosphere. Light pollution can be reduced by using more efficient lighting fixtures (for example, fixtures that control the direction of the light and use less energy) and by developing better energy conservation habits.
Academic standards correlations on Teachers' Domain use the Achievement Standards Network (ASN) database of state and national standards, provided to NSDL projects courtesy of JES & Co.
We assign reference terms to each statement within a standards document and to each media resource, and correlations are based upon matches of these terms for a given grade band. If a particular standards document of interest to you is not displayed yet, it most likely has not yet been processed by ASN or by Teachers' Domain. We will be adding social studies and arts correlations over the coming year, and also will be increasing the specificity of alignment.