Explore how populations change over time in a NetLogo model of sheep and grass. Experiment with the initial number of sheep, the sheep birthrate, the amount of energy sheep gain from the grass, and the rate at which the grass re-grows. Remove sheep that have a particular trait (better teeth) from the population, then watch what happens to the sheep teeth trait in the population as a whole. Consider conflicting selection pressures to make predictions about other instances of natural selection.

Explore the relationship between the genetic code on the DNA strand and the resulting protein and rudimentary shape it forms. Through models of transcription and translation, you will discover this relationship and the resilience to mutations built into our genetic code. Start by exploring DNA's double helix with an interactive 3D model. Highlight base pairs, look at one or both strands, and turn hydrogen bonds on or off. Next, watch an animation of transcription, which creates RNA from DNA, and translation, which 'reads' the RNA codons to create a protein.

Determine the dew point temperature for your classroom through a hands-on experiment. Use humidity and temperature probes to investigate the temperature at which it would rain in your classroom! Learn about water density and the conditions necessary to produce fog or rain.

Diffusion is the net movement of particles from areas of high concentration (number of particles per unit area) to low concentration. In this activity, students use a molecular dynamics model to view the behavior of diffusion in gases and liquids.

Movement of ions in and out of cells is crucial to maintaining homeostasis within the body and ensuring that biological functions run properly. The natural movement of molecules due to collisions is called diffusion. Several factors affect diffusion rate: concentration, surface area, and molecular pumps. This activity demonstrates diffusion, osmosis, and active transport through 12 interactive models.

The interactions of electrons with matter have great explanatory power and are central to many technologies from transistors, diodes, smoke detectors, and dosemeters to sophisticated imaging, lasers, and quantum computing. A conceptual grasp of the interactions of electrons in general allows students to acquire deeper understanding that can be applied to a very broad range of technologies.

Use a series of interactive models and games to explore electrostatics. Learn about the effects positive and negative charges have on one another, and investigate these effects further through games. Learn about Coulomb's law and the concept that both the distance between the charges and the difference in the charges affect the strength of the force. Explore polarization at an atomic level, and learn how a material that does not hold any net charge can be attracted to a charged object. Students will be able to:

Explore the concept of evaporative cooling through a hands-on experiment. Use a wet cloth and fan to model an air-conditioner and use temperature and relative humidity sensors to collect data. Then digitally plot the data using graphs in the activity. In an optional extension, make your own modifications to improve the cooler's efficiency.

In this activity, students study gas laws at a molecular level. They vary the volume of a container at constant temperature to see how pressure changes (Boyle's Law), change the temperature of a container at constant pressure to see how the volume changes with temperature (Charles’s Law), and experiment with heating a gas in a closed container to discover how pressure changes with temperature (Gay Lussac's Law). They also discover the relationship between the number of gas molecules and gas volume (Avogadro's Law). Finally, students use their knowledge of gas laws to model a heated soda can collapsing as it is plunged into ice water.

The Geniverse software is being developed as part of a five-year research project funded by the National Science Foundation. Still in its early stages, a Beta version of the software is currently being piloted in six schools throughout New England. We invite you to try the current Beta version, keeping in mind that you may encounter errors or pages that are not fully functional. If you encounter any problem, it may help to refresh or reload the web page.

Build your own miniature "greenhouse" out of a plastic container and plastic wrap, and fill it with different things such as dirt and sand to observe the effect this has on temperature. Monitor the temperature using temperature probes and digitally plot the data on the graphs provided in the activity.

Explore how the Earth's atmosphere affects the energy balance between incoming and outgoing radiation. Using an interactive model, adjust realistic parameters such as how many clouds are present or how much carbon dioxide is in the air, and watch how these factors affect the global temperature.

Make your own miniature greenhouse and measure the light levels at different "times of day"--modeled by changing the angle of a lamp on the greenhouse--using a light sensor. Next, investigate the temperature in your greenhouse with and without a cover. Learn how a greenhouse works and how you can regulate the temperature in your model greenhouse.

Discover how electricity can be converted into other forms of energy such as light and heat. Connect resistors and holiday light bulbs to simple circuits and monitor the temperature over time. Investigate the differences in temperature between the circuit with the resistor and the circuit using the bulb.

Being able to control the movement of electrons is fundamental for making all electronic devices work. Discover how electric and magnetic fields can be used to move electrons around. Begin by exploring the relationship between electric forces and charges with vectors. Then, learn about electron fields. Finally, test your knowledge in a fun "Electron Shooting" game!

Use the Sound Grapher to create visualizations of sound and learn about the frequency, wavelength, amplitude and velocity of sound waves.

The microscopic world is full of phenomena very different from what we see in everyday life. Some of those phenomena can only be explained using quantum mechanics. This activity introduces basic quantum mechanics concepts about electrons that are essential to understanding modern and future technology, especially nanotechnology. Start by exploring probability distribution, then discover the behavior of electrons with a series of simulations.

In this investigation, students will explore the question: Can there be life outside of Earth? Students will use planet hunting models to discover how scientists find new planets and perform simulated spectroscopic measurements to determine if the chemical requirements for life are present.

Isaac Newton's famous thought experiment about what would happen if you launched a cannon from a mountaintop at a high velocity comes to life with an interactive computer model. You are charged with the task of launching a satellite into space. Control the angle and speed at which the satellite is launched, and see the results to gain a basic understanding of escape velocity.

This NetLogo model of leaf photosynthesis shows the macroscopic outcome of the reaction.