Light Energy. Lana Tiernan Mrs. Branin 2016

Transcription

1 Light Energy Lana Tiernan Mrs. Branin 2016

2 What is Light? Light is something very important that is in our everyday lives. We usually don't realize how much we need it. Light is something that allows you to see the world around you. Light comes from the sun, a burner flame (fire), and a light bulb. You cannot see anything in a room that is completely pitch black, unless it is glow in the dark, of course. Light gives off energy making our eyes able to notice everything in your world.

3 How Does it Travel? Light travels in straight lines called light rays. They spread out in all directions from the lit object. Light travels extremely quickly, and fills the entire room you are in. Even the sun lights up half of the entire earth during the daytime. Sometimes, when an item is in front of or near a lit object, it will create a shadow on the nearest wall.

4 Concave Mirrors Concave mirrors are similar to the inside of a spoon, and they curve in on the shiny side. These types of mirrors can form different types of images that depend on the position of the object in relation to the mirror. When you are looking in the mirror from a long distance, your image appears large and upside down. When you are looking in the mirror from a short distance, your image appears large and right side up. When you move farther away from the mirror your image stays upside down but appears smaller and smaller. The mirror isn't moving, it all depends on your view.

5 Convex Mirrors Convex mirrors allow you to see in all directions. You may recognize these mirrors from a store or the side view mirrors of a car. Convex mirrors curve out on the shiny side. When looking in a convex mirror, your image appears right side up and small. Now you know when you look at the side view mirror of the car, it's a convex mirror.

6 What is Polarization? Polarization is something that most people know of but just don't know the NAME of. You know when it's a really sunny day and when you are inside the car, the top of the front windshield seems tinted or sometimes even...blue? That is an example of polarization. Sunglasses are also polarized. Polarized is a synonym for tinted. Polarization is used for blocking light, but not all the way. It seems as if it's almost translucent. It also is known as a form of waves.

7 Some Words You Should Translucent- permitting light to pass through but diffusing it so that people, objects, etc., on the opposite side are not clearly visible Opaque- not transparent nor translucent; impenetrable to light; not allowing light to pass through. Transparent- having the property of transmitting rays of light through its substance so that bodies situated beyond or behind can be distinctively seen. Know

8 Refraction is known as the change in direction of propagation of a wave due to change in its transmission medium. Think, if you skate from a sidewalk onto grass at a 90 degree angle, you will slow down all at once. But if you come from a different angle, one skate will slow down faster than the other, causing it to change direction or refract. It is the same with light rays. In the picture on the right, a pencil looks split in two or bent. That is caused by refraction. Refraction

9 How Concave and Convex Mirrors Form Images Concave and convex mirrors form weird looking images. In a concave mirror, you appear enlarged and right side up. Objects that are farther away appear enlarged and upsidedown. When you move farther and farther from it, you remain upside down and get smaller and smaller. When looking in a concave mirror, your image depends on your position in relation to the mirror. But convex mirrors aren't really funky. In a convex mirror, you'd appear reduced, but upright.

10 What Happens When Light Passes Through Matter? As I explained earlier, when light passes through matter, it mostly depends on what type of material that matter is. And no, not solid, liquid or gas, but opaque, transparent or translucent. Some light isn't permitted to pass through matter. Take my desk for example. Light cannot pass through it, because it is an opaque material. Now, glass on the other hand, allows all light to pass through it, if it is clear glass, not frosted.

11 Prisms are very cool things that interfere with light. When light hits a prism, the light is refracted differently and then it leaves the prism at different angles, creating an effect that is similar to a rainbow. This is also used to separate a beam of white light into many varieties of colors. Prisms are glass objects, usually shaped as triangles or other shapes. They are super cool to use and create astonishing things. Prisms

12 Electromagnetic Spectrums Did you know that an electromagnetic spectrum is actually a map of all the types of light that we can identify? But not all light is in the visible spectrum, which is all of the light that you can see. What I'm saying is, there are types of light, some even are colors, that our eyes cannot see! Imagine that. A whole other world of color that our silly eyes can't see. These strange colors are called infrared colors. The electromagnetic spectrum helps our eyes detect the colors that we are able to see. One color called ultraviolet is something that the human eye can't see. On the right, look below the word "ultraviolet". It appears grey, right? That's why we aren't able to see the actual color. The electromagnetic spectrum also helps detect different sorts of waves.

13 So, the next time you think about light, you'll think about all of the things that help create it!

14 Thanks for watching! A presentation by Lana Tiernan