Build a device to accomplish a fun task. Accept a design trade-off challenge of using only a set amount of simple materials, as if you were stuck on a desert island, to make your device work.

The goal of this science fair project is to build batch solar collectors from different colors of plastic bags and see which collector is the most efficient in heating water.

In this project, you will estimate the circumference of the earth, using a method developed about 2,200 years ago, by Eratosthenes, a Greek mathematician and the librarian of the great library at Alexandria, in Egypt.

Do you like to look up into the night sky? There are so many stars, it can be mind boggling. Some ancient people marked time by the changes in star patterns. We still use changes in constellation patterns to mark astronomical time. This activity explores whether constellations change more in one hour, one day, one month, or one year.

Humans need food, water, and warm shelter to survive. But a lot of humans depend on fossil fuels to supply gas and electricity to heat our homes. But burning fossil fuels to create energy is harmful to the environment. In this science fair project, you will build a solar air heater as an attempt to provide free heat to homes without burning fossil fuels.

There are many different types, or genres, of computer and video games. This includes racing, fighting, sports, adventure, and puzzle games. Survey your classmates in this science fair project to find out if certain genres of games appeal more to males and other genres more to females.

In this environmental science fair project, students will build models of fields prepared by plow-based and no-till methods, and see which ones are best at retaining soil moisture and preventing surface runoff.

The funny thing about friction is that you couldn't get anywhere without it, yet it still acts to slow you down as you're getting there. Here is an easy project to measure the effects of friction.

Enzymes speed up chemical reactions by factors of at least a million. This project investigates some of the factors that affect how fast enzymatic reactions occur.

We all recognize what friction is, but do you really understand what causes it? This project focuses on friction, its causes and forces and specifically how it affects how fast you can slip down slides.

Every criminal leaves behind evidence at the crime scene. The trick to catching the criminal is collecting all of the evidence and making sense of it. This is what the forensic expert does. In this science project you will be correlating the size of blood stains to the distance from which a body fell, but don't get too grossed out. You'll be doing it with water-filled balloons.

People often draw conclusions from a small number of observations, but how easy is it to draw the wrong conclusion? Here is a simple project that shows the importance of making enough observations before making a prediction.

Have you ever dreamed of a world where you could take the scraps from last night's dinner and toss them into your car's fuel tank and make gas? Well, we're not quite in "Back to the Future" yet, but in this energy science fair project, you'll discover that food scraps, dead plants, sawdust, and other decaying organic matter, called biomass are a rich source of energy. You can get energy out of biomass by burning it, turning it into a liquid, or by turning it into a gas called biogas. You've probably burned biomass (like dead wood) before if you've ever built a campfire, and you've seen biogas being produced if you've ever watched cows happily munching on green grass. The cows eat a type of biomass (grass or hay) and turn it into the biogas, methane, in their digestive tracts. In this energy science fair project, you'll compare the amounts of biogas produced by different types of biomass.

Lots of people have preconceived ideas and perceptions of people because of stereotypes. This science fair project will help you examine whether the stereotypes of "gamers" actually matches those that actually play video games.

Have you ever stopped to watch a trail of ants moving back and forth between a food source and their nest? Have you ever wondered how they establish their trail? You've probably read that ants use chemical signals to communicate with one another. This is a relatively simple experiment that you can do to determine whether ants use attractant signals (positive cues) or repellant signals (negative cues) or both.

Oil spills devastate wildlife and our precious water resources. Test the absorptivity of different materials (sorbents) to discover which ones are best at removing oil from water in this brief lab.

This physics project seems like it should have an easy answer. Instead, it turns out to be a great illustration of why it is important to base scientific conclusions on the outcome of controlled experiments. Things don't always turn out as we expect.

Leaves use sunlight to make food for the plant. Sunlight contains all of the colors of the rainbow, but are all of those colors used by the leaf? Can you find out if some colors of light are more important than others?

By making a simple sled kite from the template provided and using the suggestions in the Science Buddies project, you can experiment with variables that test different aspects of flight. The Science Buddies project ideas are set up consistently beginning with an abstract, objective, and introduction, followed by a section on terms, concepts, and questions, bibliography, list of materials and equipment, experimental procedure, suggestions on how to vary the experiment, plus a focus on the sort of careers this experiment might relate to.

Many substances are actually mixtures of different things. For example, milk, which looks like it is one substance, is actually a mixture of many different solids and liquids. Chromatography is a technique that is used to separate mixtures. In this experiment you will study the substances that make up different inks by using paper chromatography.