Golden Brain 100 Science Edition

Author: Compiled by the Press
Publisher:
Publish Date: 2003-09-01
Features: A drop of water can become a mighty river, flowing forward. Every year, rivers around the world transport 1.8 billion tons of sediment, truly giants capable of moving mountains and filling seas. Where does the power of rivers come from? "Water flows downhill" is the result of Earth's gravity converting potential energy into kinetic energy, giving the river its force. The greater the elevation change, the faster the flow and the greater the kinetic energy. The more water, the greater the power. China has abundant hydropower resources, but only a small percentage are currently utilized. Can you name the world's five major rivers?
People have seen rainbows for a long time, but they didn't know what caused them until Newton used a prism to split white light into single-colored light. This revealed that white light is a complex form of light, containing seven types of single-colored light: red, orange, yellow, green, blue, indigo, and violet. Back then, Newton painstakingly crafted the prism. Now, here’s a simple way to observe seven-colored light using a "water prism." Wrap a mirror with aluminum foil, cut out a small "window" measuring 25 mm × 25 mm with a knife, and place it diagonally in a water-filled basin, facing the sunlight. Hold a piece of white paper at a diagonal angle above the mirror and rotate it around the mirror until a colorful light band appears on the paper.
In this experiment, what is the prism?