Physics P1 - Electromagnetic Waves

Physics P1 - Electromagnetic Waves

1. Electromagnetic Spectrum

   • Radio Microwaves Infrared Visible light UV X- Rays Gamma
   • Radio is largest
   • Gamma is smallest
   • Can travel through vacuum

2. Light, Infrared, Microwaves and Radio Waves

   • White light contains all colours of the spectrum
   • All used for communiaction

3. Communication

   • Radio waves used for communication
   • Microwaves used for satellite TV
   • Mobile phones may not be safe- research needed

4. Expanding Universe

   • Doppler Effect- Waves compressed in direction of movement, spread out behind
   • Galaxy- Large collection of stars
   • Red Shift- Light observed from galaxies shifted towards longer wavelength, so are moving away from us
   • Further away, bigger the red shift

5. Big Bang

   • Release of energy from an initial point
   • Continually been expanding
   • Cosmic Microwave Background Radiation- Electromagnetic radiation created just after Big Bang