Shop Windows to the Universe

Become a nitrogen atom in the nitrogen cycle in our Traveling Nitrogen Classroom Activity Kit/Game. See all our games, activity kits and classroom activities.
Example of a stable and an unstable equilibrium, respectively.
Click on image for full size

Stability

When someone pushes you on a swing, do you keep going in the same direction or do you swing back the other way? If it wasn't a really strong push, you come back. That's because a swingset is a stable system. That means if you don't do anything after you get pushed then you will return to where you started. If the swingset was unstable then you would keep going with just a little push and not end up where you started.

The atmosphere can be either stable or unstable. If it's unstable then clouds can form. If it's really unstable then a lot of clouds can form and turn into a storm and then begin to rain.
Last modified May 26, 2004 by Jennifer Bergman.

Shop Windows to the Universe Science Store!

Cool It! is the new card game from the Union of Concerned Scientists that teaches kids about the choices we have when it comes to climate change—and how policy and technology decisions made today will matter. Cool It! is available in our online store.

Windows to the Universe Community

News

Opportunities

You might also be interested in:

Science, Evolution, and Creationism

How did life evolve on Earth? The answer to this question can help us understand our past and prepare for our future. Although evolution provides credible and reliable answers, polls show that many people turn away from science, seeking other explanations with which they are more comfortable....more

Tornado Forecasts

Tornadoes are hard to forecast. They don't last very long so there's not much time to figure out what's happening. Also, scientists don't really know how they form. They know what the weather's like when...more

Wave Beats

Sound travels in waves. When the waves hit your ear, you hear a sound. Have you ever noticed the waves in the ocean? They go up and down, up and down. Sound waves act the same way. The number of times...more

Chasing Tornadoes

Storm chasers are different than storm spotters. Chasers travel around Tornado Alley looking for severe storms and tornadoes. Sometime there are dozens of chasers following the same storm. All kinds of...more

Energy Density

A tornado is the most destructive natural storm. You might think that this also means that tornadoes are the strongest storms; that's not the case. In fact, a thunderstorm which produces a tornado can...more

The Doppler Effect

The Doppler effect was named after Christian Doppler, who first came up with the idea in 1842. He learned that sound waves would be pushed closer together if the source of the sound was moving toward you....more

Common Tornado Myths

Has someone told you to open your windows during a tornado? Or has someone told you that you don't have to worry about tornadoes because the place where you live is protected? These are two of the most...more

Tornado Notification

Tornadoes are very dangerous. This is why it's important to know when they are going to form. Forecastors at the National Weather Service are always looking for storms that could pop up. Nobody knows exactly...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA