2 What is Light?Light is composed of particles called photons which are massless bundles of concentrated electromagnetic energy and the travel in waves. Transverse Waves
3 Light travels in straight lines: Properties of LightLight travels in straight lines:Laser
4 Light travels VERY FAST – around 300,000 kilometres per second. At this speed it can go around the world 8 times in one second.A light-year is the distance light travels in one year and is a unit of measure.
5 Light travels much faster than sound. For example: Thunder and lightning start at the same time, but we will see the lightning first.2) When a starting pistol is fired we see the smoke first and then hear the bang.
6 ElectromagneticElectromagnetic waves- is energy traveling in a wave that is partially electric and partially magnetic.Electromagnetic Spectrum- all the electromagnetic waves that reach earth.
7 Electromagnetic Spectrum Radio, microwaves, infrared, visible light, ultraviolet, x-rays and gamma raysOrganized from longest wavelength to shortestWe have various uses for each type of wave
8 ColorWhite 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:This is how rainbows are formed: sunlight is “split up” by raindrops.
9 The colors of the rainbow: (ROY G BIV) RedOrangeYellowGreenBlueIndigoViolet
10 Objects and LightTransparent Objects- visible light can pass through them. Example: Clear glassOpaque Objects- No light passes through them . Example wood, bricks etc.Translucent Object- some light passed through . Example: Frosted Glass
11 Shadows Shadows are places where light is “blocked”: Rays of light A shadow is formed where light can’t reach.The larger the light source the larger the shadow.Shadows are places where light is “blocked”:Rays of light
12 PolarizationLight waves are transverse and that means they can be polarized-when waves travel in one direction.Polarized lenses filter light and caused it to be polarized reducing glare.