1. Properties of light

2. Learning goals We are learning the properties of light.
We are learning the components of the electromagnetic spectrum.

3. Basic properties of light
1. Light travels at tremendous speed.
c = 3.0 X 108 m/s ( m/s)
300 Earth diameters per second

4. Fun facts The Earth to the Moon: 1.255 seconds
The Sun to Earth: 8.3 minutes
Our Sun to the next closest star: 4.24 years
Across our Milky Way galaxy: 100,000 years
To the closest spiral galaxy (Andromeda): 2.5 million years
Limit of the observable universe to Earth: 13.7 billion years

5. Basic properties of light
2. Light travels in straight lines
Linear Propagation
Light radiates in all directions from a luminous object
Radiation: method of energy transfer that does not require a medium; energy travels at the speed of light

6. Basic properties of light
3. Light travels as waves
Although light travels in straight lines, individual photons (bundles of energy) travel as waves
Compare to a care traveling along a straight road
Electromagnetic waves

7. Since light travels as waves
Many waves of energy of different wavelengths can travel together
Some wavelengths are visible to the human eye and others are not
Each colour we see is a different wavelength

8. Electromagnetic spectrum

9. Learning goals We are learning the properties of light.
We are learning the components of the electromagnetic spectrum.