DO NOW In your notes… answer the following question using bullet points: What do you know about light? Causes sunburn Allows plants to make food Allows us to see Form of energy

Properties of Light

Essential Question “How do astronomers learn/study what is beyond our atmosphere?” Today’s Objectives: Investigate the properties of light Explain the role of light in astronomy

Light is the common term for electromagnetic radiation traveling through space as waves. Speed of light = 3.0x108 m/s

Electromagnetic Radiation Electromagnetic Radiation is any form of energy that moves like a wave through space Organized on the Electromagnetic Spectrum according to wavelength and frequency

Parts of a wave Wavelength (l) = Length of one wave Measured in unit of distance (m, nm, etc.) l Frequency(v) = number of cycles in one second Measured in hertz 1 hz = 1 cycle/second

Electromagnetic Radiation There are many Different l and n Higher Energy = Higher Frequency / Lower Wavelength Radio waves, microwaves, x rays and gamma rays are all examples. Visible Light is only the part our eyes can detect. a m m a R a d i o R a y s w a v e s

Electromagnetic Spectrum

Creation of light Light can be created in 3 ways: The Sun Light Bulbs – Electricity or batteries Chemicals – Fireworks, explosion, chemical reactions

Refraction The bending of light as it passes between materials of different optical density

Reflection The abrupt change in direction or bouncing off of a wave

Color Visible Light Spectrum (ROY G. BIV) White light is a mixture of every color of the rainbow Black is the absence of color Observed color – the color you see is the color the object reflects back to your eyes