the Public Broadcasting Service and
the WGBH Educational Foundation
This web page provides free access to Saved By the Sun, a 53-minute video produced by NOVA that explores how solar energy is being used to power homes, businesses, and entire communities. It takes a realistic view of solar power -- both its promises and challenges -- and the hope it holds for powering the future. The movie is supplemented by additional resources, including an interactive trip inside a photovoltaic cell and a look at new solar technologies.
6-8: 4D/M9. Materials vary in how they respond to electric currents, magnetic forces, and visible light or other electromagnetic waves.
4E. Energy Transformations
3-5: 4E/E2c. A warmer object can warm a cooler one by contact or at a distance.
6-8: 4E/M2. Energy can be transferred from one system to another (or from a system to its environment) in different ways: 1) thermally, when a warmer object is in contact with a cooler one; 2) mechanically, when two objects push or pull on each other over a distance; 3) electrically, when an electrical source such as a battery or generator is connected in a complete circuit to an electrical device; or 4) by electromagnetic waves.
6-8: 4E/M3. Thermal energy is transferred through a material by the collisions of atoms within the material. Over time, the thermal energy tends to spread out through a material and from one material to another if they are in contact. Thermal energy can also be transferred by means of currents in air, water, or other fluids. In addition, some thermal energy in all materials is transformed into light energy and radiated into the environment by electromagnetic waves; that light energy can be transformed back into thermal energy when the electromagnetic waves strike another material. As a result, a material tends to cool down unless some other form of energy is converted to thermal energy in the material.
6-8: 4E/M6. Light and other electromagnetic waves can warm objects. How much an object's temperature increases depends on how intense the light striking its surface is, how long the light shines on the object, and how much of the light is absorbed.
3-5: 4F/E3. Light travels and tends to maintain its direction of motion until it interacts with an object or material. Light can be absorbed, redirected, bounced back, or allowed to pass through.
8. The Designed World
8C. Energy Sources and Use
6-8: 8C/M4. Electrical energy can be generated from a variety of energy resources and can be transformed into almost any other form of energy. Electric circuits are used to distribute energy quickly and conveniently to distant locations.
6-8: 8C/M5. Energy from the sun (and the wind and water energy derived from it) is available indefinitely. Because the transfer of energy from these resources is weak and variable, systems are needed to collect and concentrate the energy.
9-12: 8C/H5. Decisions to slow the depletion of energy resources can be made at many levels, from personal to national, and they always involve trade-offs involving economic costs and social values.
%0 Electronic Source %D September 27, 2007 %T NOVA: Saved by the Sun %I Public Broadcasting Service %V 2016 %N 30 May 2016 %8 September 27, 2007 %9 text/html %U http://www.pbs.org/wgbh/nova/tech/saved-by-the-sun.html
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