Science - Light

What is light?

Light is a form of energy that travels in waves and is visible to the human eye.

What is the speed of light?

The speed of light in a vacuum is approximately $299,792,458$ meters per second.

What is refraction?

Refraction is the bending of light rays as they pass from one medium to another.

What is the difference between transparent, translucent, and opaque materials?

Transparent materials allow light to pass through easily; translucent materials allow some light to pass through but scatter it; opaque materials do not allow light to pass through.

What are primary colours?

a colour of light that cannot be formed by any other colour: red, green or blue (the 3 colours the human retia can detect).

What is a spectrum?

All visible colours separated out into a band; a “rainbow”

What is the angle of incidence?

The angle of incidence is the angle between the incoming light ray and an imaginary line called the normal, which is perpendicular to the surface at the point where the light hits.

What is the angle of reflection?

The angle of reflection is the angle between the outgoing light ray and the normal line at the point where the light reflects off a surface.

What does it mean to absorb light?

To absorb light means that a material takes in light energy, so it doesn’t bounce back or pass through.

What is the angle of refraction?

The angle of refraction is the angle between the light ray that bends and the normal line when light passes from one substance to another.

What is a convex lens?

A convex lens is a lens that is wider in the middle and causes light rays to come together.

What color is cyan?

Cyan is a blue-green color and one of the colors made by mixing blue and green light.

What is diffuse scattering?

Diffuse scattering happens when light hits a rough surface and spreads out in many directions.

What is dispersion?

Dispersion is when light spreads out into its different colors, like a rainbow created by a prism.

What does it mean to emit light?

To emit light means to give off light, as seen in sources like the sun or light bulbs.

What is an incident ray?

An incident ray is a ray of light that is approaching and hitting a surface.

What is a luminous object?

A luminous object produces its own light, like the sun or a light bulb.

What is a non-luminous object?

A non-luminous object does not produce light and can only be seen when light reflects off it.

What is the normal line in optics?

The normal line is an imaginary line that stands straight up from a surface where light hits it; it helps us measure angles.

What is an opaque material?

An opaque material does not let any light through, so you cannot see through it.

What is a primary color of light?

Primary colors of light are red, green, and blue; these colors can be mixed to create other colors.

What is a ray in terms of light?

A ray is a straight line that shows the direction in which light travels.

What is refraction in optics?

Refraction is when light bends as it moves from one material into another due to a change in speed.

What is a secondary color of light?

A secondary color of light is made by mixing two primary colors; for example, cyan is made by mixing green and blue.

What is the spectrum of light?

The spectrum of light is the range of colors that light can show, like red, orange, yellow, green, blue, indigo, and violet.

What is specular reflection?

Specular reflection happens when light bounces off a smooth surface, like a mirror, in a clear way.

What is a translucent material?

A translucent material lets some light through, but not enough to see through it clearly.

What does it mean to transmit light?

To transmit light means to allow light to pass through a material.

What is a transparent material?

A transparent material allows light to pass through clearly, so you can see through it like glass.