Marlborough Primary School Thursday 26 th March MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH Light travels in straight lines MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH Light travels from a source to our eyes. We can see sources in a dark room. Light can travel through transparent objects. Translucent objects let a bit of light through. MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH If there is no light: we cannot see anything! Let s try a test: Put a few small objects into the black bag ! MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH Light bounces off and some reaches our eyes. We can try this with rough surfaces and shiny surfaces. MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH When light bounces off something we say the light is reflected. If we move the mirror. The light reaches a different place on the wall. MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH Look into a mirror: Light is reflected We see the reflection MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH Lasers are very bright light sources, where all the atoms give out light at the same time. The surface has tiny pits and smooth bits in a spiral pattern The pits scatter light from a laser The smooth bits reflect the light and a coded message is read. MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH Nucleus surrounded by orbiting electrons Heat atom up Electron jumps into bigger orbit Cool atom down Electron jumps back Electron emits light energy MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH Depends on how big the jump between orbits was The bigger the jump, the higher the energy ( ) The energy determines the colour MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH wavelength The wavelength of a wave is the distance between a point on one wave and the same point on the next wave. The colour of the light depends on the wavelength MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH 300,000 km / s = 300,000,000 m / s Earth is 149,600,000 km from sun Speed = Distance = 149,600,000 = s = 8.32 minutes Time 300,000 All kinds of light travel at one speed Faster than sound Really fast! See lightning before we hear thunder See fireworks before we hear the BANG MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH White light is made up of all of the colours. When light enters different objects, it slows down and bends. Some objects can be used to separate light into different colours. FAST slow FAST MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH When light passes through some objects, it slows down MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH Red, green and blue are used for stage lighting. MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH Red Green Cyan Yellow Magenta Other colour effects are made by mixing these three lights. MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH The colour an object appears depends on the colours it absorbs or reflects. MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH The colour an object appears depends on the colours it absorbs or reflects. MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH An artist on stage wears a red t-shirt with a yellow star motif, and blue trousers. Complete the table showing how his costume appears under different colour lighting. MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH MARLBOROUGH PRIMARY SCHOOLTHURSDAY 26 TH MARCH