Science 8 Optics

Matter

Anything that has mass and takes up space

light

is a form of energy

Radiometer

a device that was invented to measure energy from the sun

Energy has the ability

to make things move or produce a change in materials

incandescent

brilliant; giving off heat or light by burning or getting so hot it glows

luminescent

emitting light not caused by heat

types of luminescent light

fluorescent, phosphorescent, chemiluminescent

fluorescent

gives off energy while supplied with electricity

light comes in a tube

very energy efficient

phosphorescent

• stores and releases energy gradually as light

• ex. glow in the dark toys

chemiluminescent

• light result of a chemical reaction between substances.

• ex. fire flies

examples of incandescent

• candle

• light bulb(old school)

Acronym ROYGBIV means:

• red, orange, yellow, green, blue, indigo, violet

Light travels

electromagnetic waves

The longer the wavelength, the _____ the energy

lower

red is a ________________wavelength

long

Violet is a____________________-wavelength

short

How does light travel?

in all directions from its source

Photons are

particles of light

rays

A straight line used to represent a light wave.

Light can travel through

empty space, and through matter

light can be

reflected, absorbed, transmitted

reflected

Light that is bounced off the surface of an object

refracted

light deflected from a straight path

When light enters water it

bends and slows down a little

transparent

Allowing light to pass through

translucent

Permitting light to pass through, but not transparent

opaque

impossible to see through; preventing the passage of light

luminous

emitting its own light

non luminous

Does not produce its own light

luminous example

candle

non luminous example

moon

light can be created by

vibration of electrically charged particles

Synonym of light

electromagnetic radiation

light can transfer its energy in the forms of:

light and heat

visible light

Electromagnetic radiation that can be seen with the unaided eye

EM means

electromagnetic radiation

The longer the wavelength the ____________energy the EM wave carries

less

Gamma rays

Electromagnetic waves with the shortest wavelengths and highest frequencies

Prism

device used to separate light into its colors

A black object looks black because

it absorbs all light

a white object looks white because

it reflects all light

Issac Newton

discovered connections between color and light

rainbow

an arc of colored light in the sky caused by refraction of the sun's rays by rain

Rainbows can be seen

only at certain times of day

vacuum

A space where no particles of matter exist

Light ___________________ from the Sun when entering our atmosphere

slows

Frequency

the number of complete wavelengths that pass a point in a given time

Wavelegnth

distance between wave crests

Crest

Highest point of a wave

Trough

Lowest point of a wave

cycle

a wave from crest to crest or trough to trough

Wavelength

Horizontal distance between the crests or between the troughs of two adjacent waves

Hertz

Unit of frequency

Hz

Hertz

Microwaves uses

the water particles in food to cause them to move and heat the food

infrared waves example

TV remote

The law of reflection says that

the angle of incidence equals the angle of reflection

angle of incidence

the angle between the incident ray and the normal

angle of incidence

equals the angle of reflection

Refraction of light

When light travels through one medium into another its speed changes

Rainbows are caused by

refraction

normal

A line perpendicular to a surface

concave lens

A lens that is thinner in the center than at the edges

convex lens

A lens that is thicker in the middle than at the edges

Cornea

The clear tissue that covers the front of the eye

Retina

Light sensitive layer of the eye; contains rods and cones

total reflection

When the wave hits a boundary, none of the wave enters the new medium and all of the wave reflects off the boundary.

color addition

combining colors of light to produce new colors

color subtraction

identifying which color or colors of light are subtracted (absorbed) and which are reflected from the original set

Synonym of myopia

nearsightedness

hyperopia

farsightedness