How is visible light detected?
By our eyes
part of the electromagnetic spectrum
How can we see different colours with visisble light?
Seeing different wavelengths
What happens going from violet to red
visibile light spectrum?
Wavelength increases across
What is the mixture of all the colours
visible light spectrum?
What is an important skill for photography?
Using different shades and colours within visible light
What is infrared radiation emitted from?
What happens the hotter the object is?
More infrared radiation it emits
Remote controls for devices such as TVs and DVD players use?
Infrared radiation (IR)
What can infrared radiation be transmitted along?
What is infrared radiation used in?
Special camers that allow people to see in dark
Where are microwaves used in?
What do microwave transmitters produce?
Wavelengths that are able to pass through the atmosphere
Another purpose for microwaves?
- Used to sned signals to and from satellites for TV programs
- Microwaves are also used in microwave ovens for heating food
What are radiowaves used to?
Transmit radio and TV programmes
What type of radiation do mobile phones used?
Use microwave radiation and radio waves
How is microwave radiation and radio waves hazardous
Penetrate your skin and absorbed by body tissue
causing internal heating and damage
how is it hazardeous?
Absorbed by skin and too much causes you to get burnt
Experiment to see better emitter of infrared radiation
- Cans with light surface and can with black surface
- Fill can with hot water with same temp
- Leave can for same time
- Can with low temp , best emitter
Expierment to test best absorber of IR