The Big Bang

Basics of Waves
1. Amplitude
  1. Displacement from rest position to crest
2. Wavelength
  1. The length of a full cycle of the wave
  2. Crest to Crest
3. Transverse Waves
  1. Vibrations are perpendicular (at 90°) to the direction of energy transfer of the wave
  2. Light, Waves on Strings, Ripples
4. Longitudinal Waves
  1. The vibrations are parallel to the direction of energy transfer of the wave
  2. Sound waves, ultrasound, shock waves
  3. Sound waves, Ultrasound, Shock waves
  4. Sound Waves, Ultrasound, Shock Waves
5. Wave Speed = Frequency x Wavelength
Waves Properties
1. Reflection
  1. What allows us to see objects
    1. Light bounces off them into our eyes
  2. Light travelling in the same direction from an...
    1. ...even surface
      1. Light is reflected at the same angle
        Clear reflection
    2. ...uneven surface
      1. Light Reflects off at different angles
  3. Angle of INCIDENCE=Angle of REFLECTION
  4. RAY DIAGRAM
Diffraction
1. Waves spreading out when at the edges when they pass through a gap or pass an obstacle
2. The longer the wavelength, the more the wave spreads out
Refraction
1. When a waves crosses a boundary between two substances it changes direction
2. Waves are only refracted if they meet a new medium at an angle
3. If they're travelling along the normal they will change speed, but are NOT refracted
The EM Spectrum
1. Uses and Dangers of EM Waves
  1. Microwaves
    1. Uses=Satellites
    2. Dangers=Burns, Cancer
  2. Radio
    1. Uses: TV, Radio
    2. Dangers=None
  3. Infra Red
    1. Uses=Cooking, Night Vision
    2. Dangers=Burns
  4. Visible
    1. Uses=Seeing
    2. Dangers=Eye Damage
  5. Ultra Violet
    1. Uses=Discos, Tanning
    2. Dangers=Skin Cancer
  6. X-Ray
    1. Uses=Medical Imagery, Security
    2. Dangers=Cancer
  7. Gamma
    1. Uses=Observing the Universe
    2. Dangers=Cancer
2. The Basics
  1. EM Waves with different wavelengths have different properties
    1. 1. All types of EM Waves travel at the same speed in a vaccum
      2. EM Waves have higher frequencies and shorter wavelengths
      3. Randy Men In Violet Underwear eXite Girls
Sound Waves
1. We hear sounds as vibrations
  1. They're passed through the surrounding medium as a series of compressions
2. Sound travels faster in solids than liquids, and faster in liquids than gases
3. Sound can't travel in space because it's mostly a vaccum
4. Reflection and Refraction
  1. Sound Waves can be reflected by hard flat surfaces
  2. Echoes are Reflected Sound Waves
  3. Sound waves will refract as they enter different media
    1. As they enter denser material, they speed up
5. The higher the frequency, the higher the pitch
The Origin of the Universe
1. Expanding
  1. Galaxies moving away from eachother
2. The Doppler Effect
3. Red-shift
  1. The more distant the galaxy, the more red it appears
4. Big Bang Theory
  1. All matter and energy in Universe was compressed into a small space
    1. It exploded from that point and started to expand
  2. 14 billion yrs ago
5. Cosmic Microwave Background Radiation
  1. low frequency electromagnetic radiation coming from all parts of the universe
  2. Universe still hot after Big Bang, high frequency radiation emitted
    1. As universe expanded and cooled, radiation dropped infrequency, seen as microwave radiation

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The Big Bang

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	Created by I Turner almost 10 years ago