Table of contentsWhat is light?How does light behave?Where does light come from?Works cited:What is light? than light?Light arrives on our planet after a rapid journey from the Sun, 149 million kilometers (93 million miles). Light travels at a speed of 300,000 km per second, so the light you see now was still hidden in the Sun about eight minutes ago. But why does light make this journey? As you probably know, the Sun is a nuclear fireball that spews energy in all directions. The light we see is simply the only part of the energy produced by the Sun that our eyes can detect. When light travels between two places (from the Sun to Earth or from a flashlight to the sidewalk in front of you on a dark night), the energy makes a trip between those two points. Energy travels in waves (similar to sea waves but about 100 million times smaller): a vibrating pattern of electricity and magnetism that we call electromagnetic energy. If our eyes could see electricity and magnetism, we could see each ray of light as a wave of electricity vibrating in one direction and a wave of magnetism vibrating perpendicular to it. These two waves would propagate over the instep and at the speed of light. Say no to plagiarism. Get a tailor-made essay on "Why violent video games should not be banned"? Get the original essay How does light behave? Light waves behave in four particularly interesting and useful ways that we describe as reflection, refraction , diffraction and interference. The only reason we can see things around us is because light, either from the Sun or from something like an electric lamp here on Earth, reflects in our eyes. Turn off the light source or block it from reaching your eyes and these objects will disappear. They do not cease to exist, but we can no longer see them. Reflection can take place in two very different ways. If you have a smooth, highly polished surface and you shine a narrow beam of light at it, you get a narrow beam of light reflected from it. This is called specular reflection and it's what happens if you shine a flashlight or laser at a mirror: you get a well-defined beam of light bouncing back towards you. Most objects are neither smooth nor highly polished: they are rather rough. So when you shine a light on them, it's scattered everywhere. This is called diffuse reflection and is how we see most objects around us as they scatter the light that falls on them. Have you noticed how your body slows down when you try to walk in water? You run on the beach at full speed, but as soon as you hit the sea, you slow down completely. No matter how hard you try, you can't run as fast in water as you can in air. Dense liquid is harder to push away, so it slows you down. Exactly the same thing happens to light if you shine it at water, glass, plastic, or another denser material: it slows down considerably. This tends to bend light waves, what we usually call refraction. Light will propagate the same way if you shine it at a small aperture roughly similar in size to its wavelength. You may have noticed this effect, called diffraction, if you close your eyes and look at a street lamp in the dark. When your eyes close, the light seems to spread in strange bands as it slips through.