What is Light?

Light

Light is an electromagnetic wave.

Electromagnetic waves can travel through

empty space or matter and consists of

changing matter and electric fields.

The electric and magnetic fields vibrate at

right angles to one another.

Electric & Magnetic Fields

An electric field surrounds every charged

object.

Electric fields pull oppositely charged objects

towards them and push like charged objects

away from them.

A magnetic field surrounds every magnet.

Magnetic fields pull metal objects towards the

magnet.

EM waves are produced

An EM wave is produced by the vibration

of an electrically charged particle.

When an electric field starts vibrating a

magnetic field is created.

The vibration of the electric and magnetic

fields creates an EM wave.

The transfer of EM waves is known as

radiation.

Speed of Light

Light waves travel at approximately 300,000 km/s.

Light waves travel approximately 880,000 times faster than sound waves.

Light travels around the Earth 7.5 times in one second.

You will use the speed formula (S = D / T) in your calculations involving the speed of light.

Light from the Sun

It takes approximately 8.3 minutes for light produced from the sun to travel the 150,000,000 km from the sun to the Earth.

The EM waves from the sun are the major source of energy on Earth.

Although Earth receives a large amount of energy from the sun the Earth receives only a very small portion of the total amount of energy produced by the sun.