LIGHT 0-4 study guide

Indentify how optic fibers work?

Light travels down a fiber optic cable by bouncing off the walls of the cable repeatedly. Each light particle (photon) bounces down the pipe with continued internal mirror-like reflection. The light beam travels down the core of the cable.

Explain why a mirage forms?

Mirages happen when the ground is very hot and the air is cool. The hot ground warms a layer of air just above the ground. When the light moves through the cold air and into the layer of hot air it is refracted (bent). A layer of very warm air near the ground refracts the light from the sky nearly into a U-shaped bend.

describe the differences between regular reflections and diffuse reflections?

Regular reflection occurs when light reflects off a very smooth surface and forms a clear image. Diffuse reflection occurs when light reflects off a rough surface and forms a blurry image or no image at all.

Contrast the causes of nearsightedness and farsightedness and how each is corrected.

The biggest difference between nearsighted and farsighted vision is where objects appear in focus. Nearsighted people see close-up objects more clearly, while farsighted people see things in the distance more clearly. Conversely, nearsightedness makes distant objects look blurry, while farsightedness blurs objects that are close to you. Nearsightedness, or myopia, is the inability to see distant objects and is corrected with a diverging lens to reduce power. Farsightedness, or hyperopia, is the inability to see close objects and is corrected with a converging lens to increase power.

laser

a device that generates a narrow beam of coherent light

index of refraction

a measure of the amount a ray of light bends when it passes from one medium to another

hologram

a three-dimensional photograph made using lasers

virtual images

an upright image that forms where light seems to come from, the image you see in a plane mirror.

complimentary colors

any two colors that combine to form white light.

pigment

colored substances that are used to color other materials.

Describe the characteristics of plane, convex, and concave mirrors?

convex:Virtual and erect, Smaller than the size of the object., Always within the focus.. plane: Images formed by plane mirrors are virtual, upright, left-right reversed, the same distance from the mirror as the object's distance, and the same size as the object. concave: Real and inverted or Virtual and erect, Smaller or larger, depending on the position of the object., Depends on the position of the object..

identify the parts of the eye and how each functions?

look at chart in book pg 127

opaque

reflects or absorbs all of the light that strikes it, you cannot see opaque material because light cannot pass through them. (wood or steel)

translucent

scatters light as it passes through, you can usually see something behind a translucent material. (frosty window)

total internal reflection

the complete reflection that takes place within a substance when the angle of incidence of light striking the surface boundary is less than the critical angle

primary colors

three colors that can combine to make any other color.

transparent

transmits most of the light that strikes it. The light passes right through without being scattered. (glass)

secondary colors

two primary colors combine in equal amounts to produce these colors

real images

when rays actually meet, they could be larger or smaller than the object.

Explain how a convex and concave lens form an image?

A concave lens causes parallel light rays to spread out. The focal point is the point at which parallel light rays meet after being reflected or refracted. Distort means to change the shape of something by twisting or moving the parts around. A convex lens forms an image by refracting light rays.

Contrast convex and concave lenses?

A concave lens is thinner in the middle and thicker at the edges. A convex lens is thicker in the middle and thinner at the edges. Used in the camera, focus sunlight, overhead projector, projector microscope, simple telescope, magnifying glasses, etc. It is also used for the correction of the problem in long sight.