Light Continued

The light models explain how we… See ____________ See ______________ in objects ______ see around corners See ________ distant objects apparent bends Can’t shadows

Light travels in ________ lines: How do we see things? Light travels in ________ lines: straight Laser

We see things because they ________ light into our eyes: reflect Astronomy

Part 2 - Reflection Reflection from a mirror: Mirror Normal Incident ray Reflected ray Angle of incidence Angle of reflection Mirror

Angle of incidence = Angle of reflection The Law of Reflection Angle of incidence = Angle of reflection In other words, light gets reflected from a surface at the same angle it hits it. The same !!!

Color We can demonstrate this by splitting white light with a prism: White light is not a single color; it is made up of a mixture of the seven colors of the rainbow. We can demonstrate this by splitting white light with a prism:

Only red light is reflected Seeing color The color an object appears depends on the colors of light it ______. reflects Homework White light Only red light is reflected

Refraction Refraction medium _________ is when waves bend or change speed due to travelling in a different medium. A _______ is something that waves will travel through. medium

Shadows Shadows are places where light is “_______”: blocked Rays of light

Shadow(s) Light from a single direction. Sun-light. Has one shadow Two light sources Two shadows

Life of a Photon – 4 Steps ________ - released ___________ – pass through an object Air, glass, water, plastic, space _____________ – reflect off surface of objects ________ – ultimately photons strike an object and disappear Emitted Transmitted Bounce/Scatter Absorbed

How light or electromagnetic radiation is used in Astronomy Astronomers use a tool called a spectroscope to separate starlight into its colors – in this way, they can tell what a star is made of, its temperature, luminosity and so on… Astronomers can look at astronomical objects at different wavelengths…