From NASA Goddard, Jewel Box Sun, a surprising video that illuminates how NASA’s Solar Dynamics Observatory (SDO) converts a wide range of invisible wavelengths into colorized images that our human eyes can see.
As the colors sweep around the sun in the movie, viewers should note how different the same area of the sun appears. This happens because each wavelength of light represents solar material at specific temperatures. Different wavelengths convey information about different components of the sun’s surface and atmosphere, so scientists use them to paint a full picture of our constantly changing and varying star.
From a yard in Kampala, Uganda, Moses explains how to build a solar oven using a tire, some glass, newspaper, silver foil, tape, a black pot, and a few hours.
If you’re cooking outside or don’t have an oven, solar ovens are a great alternative for making a hot meal. Building materials are generally inexpensive and easy to find, and rather than requiring fuel or firewood, solar ovens take advantage of a sustainable resource: the sun.How does it work?
Concentrating sunlight: A reflective mirror of polished glass, metal or metallised film concentrates light and heat from the sun on a small cooking area, making the energy more concentrated and increasing its heating power.
Converting light to heat: A black or low reflectivity surface on a food container or the inside of a solar cooker improves the effectiveness of turning light into heat. Light absorption converts the sun’s visible light into heat, substantially improving the effectiveness of the cooker.
Trapping heat: It is important to reduce convection by isolating the air inside the cooker from the air outside the cooker. A plastic bag or tightly sealed glass cover traps the hot air inside. This makes it possible to reach temperatures on cold and windy days similar to those possible on hot days.
Greenhouse effect: Glass transmits visible light but blocks infrared thermal radiation from escaping. This amplifies the heat trapping effect.
For more information about how to make different kinds of solar ovens, visit MAKE or Instructables, or come up with your own solution!
The amount of solar energy that strike the surface of the Earth in one hour is more than enough to supply every person on the planet with electricity for an entire year. However, there are limits that prevent us from being able to fully take advantage of this energy.