For thousands of years, navigators have looked to the sky for direction. Today, celestial navigation has simply switched from using natural objects to human-created satellites. A constellation of satellites, called the Global Positioning System, and hand-held receivers allow for very accurate navigation. In this lesson, students investigate the fundamental concepts of GPS technology trilateration and using the speed of light to calculate distances.

In this lesson, students will learn that math is important in navigation and engineering. Ancient land and sea navigators started with the most basic of navigation equations (Speed x Time = Distance). Today, navigational satellites use equations that take into account the relative effects of space and time. However, even these high-tech wonders cannot be built without pure and simple math concepts basic geometry and trigonometry that have been used for thousands of years. In this lesson, these basic concepts are discussed and illustrated in the associated activities.

This lesson unit provides an insight into the navigational methods of the Bronze Age Mediterranean peoples. The students explore the link between history and astronomical knowledge. Besides an overview of ancient seafaring in the Mediterranean, the students use activities to explore early navigational skills using the stars and constellations and their apparent nightly movement across the sky. In the course of the activities, they become familiar with the stellar constellations and how they are distributed across the northern and southern sky.

Produce light by bombarding atoms with electrons. See how the characteristic spectra of different elements are produced, and configure your own element's energy states to produce light of different colors.

Stimulate a neuron and monitor what happens. Pause, rewind, and move forward in time in order to observe the ions as they move across the neuron membrane.

Students examine how the orientation of a photovoltaic (PV) panel relative to the sun affects the efficiency of the panel. Using sunshine (or a lamp) and a small PV panel connected to a digital multimeter, students vary the angle of the solar panel, record the resulting current output on a worksheet, and plot their experimental results.

Through this unit, students act as engineers who are given the challenge to design laparoscopic surgical tools. After learning about human anatomy and physiology of the abdominopelvic cavity, especially as it applies to laparoscopic surgery, students learn about the mechanics of elastic solids, which is the most basic level of material behavior. Then, they explore the world of fluids and learn how fluids react to forces. Next, they combine their understanding of the mechanics of solids and fluids to understand viscoelastic materials, such as those found in the human body. Finally, they learn about tissue mechanics, including how collagen, elastin and proteoglycans give body tissues their unique characteristics. In the culminating hands-on activity, student teams design their own prototypes of laparoscopic surgical robots remotely controlled, camera-toting devices that must fit through small incisions, inspect organs and tissue for disease, obtain biopsies, and monitor via ongoing wireless image-taking. They use a (homemade) synthetic abdominal cavity simulator to test and iterate the prototype devices.

Normally we find things using landmark navigation. When you move to a new place, it may take you awhile to explore the new streets and buildings, but eventually you recognize enough landmarks and remember where they are in relation to each other. However, another accurate method for locating places and things is using grids and coordinates. In this activity, students will come up with their own system of a grid and coordinates for their classroom and understand why it is important to have one common method of map-making.

Play with a 1D or 2D system of coupled mass-spring oscillators. Vary the number of masses, set the initial conditions, and watch the system evolve. See the spectrum of normal modes for arbitrary motion. See longitudinal or transverse modes in the 1D system.

Celestial navigation is the art and science of finding one's geographic position by means of astronomical observations, particularly by measuring altitudes of celestial objects sun, moon, planets or stars. This activity starts with a basic, but very important and useful, celestial measurement: measuring the altitude of Polaris (the North Star) or measuring the latitude.

Students create and use their own simple compasses, which are each made from a bowl of water, strong magnet, stick pin and Styrofoam peanuts. They learn how compasses work and about cardinal directions. They come to understand that the Earth's magnetic field has both horizontal and vertical components.

Students learn how engineers navigate satellites in orbit around the Earth and on their way to other planets in the solar system. In accompanying activities, they explore how ground-based tracking and onboard measurements are performed. Also provided is an overview of orbits and spacecraft trajectories from Earth to other planets, and how spacecraft are tracked from the ground using the Deep Space Network (DSN). DSN measurements are the primary means for navigating unmanned vehicles in space. Onboard spacecraft instruments might include optical sensors and an inertial measurement unit (IMU).

Students expand upon their understanding of simple machines with an introduction to compound machines. A compound machine a combination of two or more simple machines can affect work more than its individual components. Engineers who design compound machines aim to benefit society by lessening the amount of work that people exert for even common household tasks. This lesson encourages students to critically think about machine inventions and their role in our lives.

Start a chain reaction, or introduce non-radioactive isotopes to prevent one. Control energy production in a nuclear reactor! (Previously part of the Nuclear Physics simulation - now there are separate Alpha Decay and Nuclear Fission sims.)

Start a chain reaction, or introduce non-radioactive isotopes to prevent one. Control energy production in a nuclear reactor! (Previously part of the Nuclear Physics simulation - now there are separate Alpha Decay and Nuclear Fission sims.)

Number Play from PhET is a sim for some of our earliest learners and includes multilingual support. This sim can be used to teach topics such as counting, cardinality, grouping, and subitizing. Students will enjoy interacting with fun objects and challenging themselves with the counting and subitizing games.

Students learn and discuss the advantages and disadvantages of renewable and non-renewable energy sources. They also learn about our nation's electric power grid and what it means for a residential home to be "off the grid."

See how the equation form of Ohm's law relates to a simple circuit. Adjust the voltage and resistance, and see the current change according to Ohm's law. The sizes of the symbols in the equation change to match the circuit diagram.

In this extension to the Ohm's Law I activity, students observe just how much time it takes to use up the "juice" in a battery, and if it is better to use batteries in series or parallel. This extension is suitable as a teacher demonstration and may be started before students begin work on the Ohm's Law I activity.

See how the equation form of Ohm's law relates to a simple circuit. Adjust the voltage and resistance, and see the current change according to Ohm's law. The sizes of the symbols in the equation change to match the circuit diagram.