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Light6 - definition is that light is a wave it has...

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Light It is very important to understand the properties of light - why? Light is the main means by which we study most astronomical phenomena. Astronomy is different than other sciences in that astronomers can't actually handle, touch, or alter in any way the stuff they study (this isn't always true - those who study planets and meteorites can sometimes touch what they study, but they're in the minority). Almost all the information we obtain is via light, so the more we know about how light works, what it is, and how we can wring out information from it, the more we can use it to discern features about the stars and galaxies which are beyond our reach. Astronomy is the most voyeuristic of all sciences - we like to watch! Exactly what is light? If you want the $25 term for it, you can say it is an oscillating electro-magnetic wave . That's pretty much a mouthful, but what does it really mean? Actually, the most important part of this
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Unformatted text preview: definition is that light is a wave ; it has wave-like properties. It, like sound or water, acts like a wave. Think of it as a wiggling, squirming thing if you like. Since light does stuff like a wave, it has a certain size. You know that not all waves are alike, and therefore not all types of light are alike. You can distinguish the different types of light by measuring the distance between consecutive peaks or consecutive valleys. This distance is known as the wavelength . Often we abbreviate it with the greek letter "lambda" - . Since it is just a distance, we can measure it in units such as centimeters (cm), millimeters (mm) or other normal units of distance. What else do we know about light? It travels. It has a certain speed, since it travels. The speed of light is denoted by the letter c , and is equal to 300,000 km/s = 186,000 miles/s. That's pretty fast....
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