Gravity governs the structure of the universe. Test your knowledge of this fundamental force with our gravity quiz!
Related HowStuffWorks Articles
- How the Sun Works
- How Volcanoes Work
- How Earthquakes Work
- How Evolution Works
- How the Nature Conservancy Works
- How the World Wildlife Fund Works
- How Asteroids Work
- How Stars Work
- How Black Holes Work
- How Compasses Work
- How Electromagnets Work
- How Landfills Work
- How Telescopes Work
- Where did the Earth come from?
- Where did the moon come from?
- Can we plug the hole in the ozone layer?
- If we stop global warming, will the polar caps refreeze?
- Could reversing global warming start an ice age?
- Will we ever run out of magma?
- Why does the North Pole move?
- Earth Day
More Great Links
- Britt, Robert Roy. "Moon Mechanics: What Really Makes Our World Go 'Round." Space.com, March 18, 2003. http://www.space.com/scienceastronomy/moon_mechanics_0303018.html
- Britt, Robert Roy. "When North Becomes South: New Clues to Earth's Magnetic Flip-Flops." Space.com, April 7, 2004. http://www.space.com/scienceastronomy/earth_poles_040407.html
- "The Carbon Cycle." NASA Earth Observatory. http://earthobservatory.nasa.gov/Library/CarbonCycle/
- Chown, Marcus. "Solar Wind to Shield Earth During Flip." New Scientist, May 15, 2004. http://www.newscientist.com/article.ns?id=dn4985
- "Cracking the Ice Age." NOVA Online. http://www.pbs.org/wgbh/nova/ice/
- "Earth's Atmosphere." NASA. http://liftoff.msfc.nasa.gov/academy/space/atmosphere.html
- "The Earth's Layers." North Dakota University System. http://volcano.und.nodak.edu/vwdocs/vwlessons/lessons/Earths_layers/Earths_layers1.html
- Glasner, Joanna. "Earth Hurtles Toward 6.5 Billion." Wired, February 21, 2006. http://www.wired.com/news/technology/0,70238-0.html?tw=wn_index_1
- "Global Warming and Our Changing Climate." United States EPA, April 2000.
- "Global Weather Patterns." BBC. http://www.bbc.co.uk/schools/gcsebitesize/geography/weather/elementsofweatherrev10.shtml
- Graham, Steve, et al. "The Water Cycle." NASA Earth Observatory. http://earthobservatory.nasa.gov/Library/Water/
- "The Great Ice Age." U.S. Geological Survey. http://pubs.usgs.gov/gip/ice_age/
- Hawkes, Nigel. "Waterworld: How will Life on Earth Look in 1000 Years." Times Online, February 17, 2006. http://www.timesonline.co.uk/article/0,,3-2044465,00.html
- Herring, David. "Ocean and Climate." NASA Earth Observatory. http://earthobservatory.nasa.gov/Library/OceanClimate/
- Illinois State Museum. "Why Are there Ice Ages?" http://www.museum.state.il.us/exhibits/ice_ages/why_4_cool_periods.html
- Larson, Josh. "Understanding Global Climate Patterns." USA Today, August 6, 2004.
- NASA Earth Observatory. http://earthobservatory.nasa.gov
- Seeds, Michael A. "Foundations of Astronomy." Wadsworth Publishing Company. 1994.
- Simkin, Tom, et al. "This Dynamic Planet." USGS. 1994.
- Smith, Lewis and Ben Hoyle. "World Has Only 20 Years to Stop Climate Disaster." Times Online, January 31, 2006. http://www.timesonline.co.uk/article/0,,2-2017322,00.html
- "Steam Explosions, Earthquakes, and Volcanic Eruptions - What's in Yellowstone's Future?" Fact Sheet 2005-3024, U.S. Geological Survey. http://pubs.usgs.gov/fs/2005/3024/
- Vastag, Brian. "North Magnetic Pole is Shifting Rapidly Toward Russia." National Geographic. December 15, 2005. http://news.nationalgeographic.com/news/2005/12/1215_051215_north_pole.html
- "What Is Photosynthesis?" Arizona State University, February 7, 2006. http://photoscience.la.asu.edu/photosyn/education/learn.html
- "Why Isn't the Earth Hot as an Oven?" NASA Earth Observatory. http://earthobservatory.nasa.gov/Library/Oven/