PHYSICS

• Prism


  Triangular glass object that breaks down white light into a rainbow of colors
• Dispersion of white light


  1. White light enters dark room

  2. White light undergoes dispersion

  3. Resulting in rainbow colors (ROYGBIV)
• Reflection


  • Light travels through matter
  • Encounters smooth surface (mirror) or rough surface (paper, wood, cloth, skin)
• Refraction


  • Light bends when it changes medium
  • Speed of light varies in each medium
• Transmission


  • Materials allow much of the light that falls on them to move through without being reflected
  • Transparent materials (glass, clear water)
  • Opaque materials do not allow transmission of light
• Absorption


  • Object does not reflect or transmit the light
  • Ability to absorb light depends on electromagnetic frequency and nature of atoms in object
• Wearing black shirts on sunny days


  Makes you feel hot
• Rayleigh Scattering


  Selective scattering of blue light in all directions (short wavelength), light travels a shorter distance
• White clouds


  Light interacts with water droplets, sunlight is equally scattered by much larger water droplets, clouds scatter all wavelengths with roughly the same effectiveness
• Reddish sunset


  Sunlight travels a longer path through the atmosphere, red as the longest wavelength, passes through pollutants
• Rainbow


  Result of refraction and reflection of light to water droplets (e.g. raindrops or fog)
• Mirage


  Deceptive appearance of a distant object or object caused by the bending of light rays (refraction) in layers of air of varying density
• Concave - curves inwards Convex - curves outwards
• Haloes


  Rings, arcs, pillars, or bright spots produced by the refraction or reflection of light by ice crystals suspended in the atmosphere (cirriform clouds, diamond dust, etc.)
• Sundogs


  Colored spots of light that develop due to the refraction of light through ice crystals, located approximately 22 degrees either left, right, or both, from the sun, depending on where the ice crystals are present
• Primary rainbow formed when a sunbeam is being refracted twice and reflected once by the droplet
• Aurora Borealis


  When a solar storm comes toward us, some of the energy and small particles can travel down the magnetic field lines at the north and south poles into Earth's atmosphere, where the particles interact with gases resulting in beautiful displays of light in the sky
• Photons or quanta


  Energy carried by light waves packaged in discrete bundles
• Triangular glass prism (1665) Resembles and dissembles white light

• White light undergoes dispersion into spectacular rainbow colors (ROYGBIV)
• Iris


  Coloured sheet of muscle which controls the amount of light which enters the eye by changing the size of the pupil
• Eyelid


  Protects the eye from physical harm
• Ciliary muscles


  Change the shape of the lens when they contract
• Vitreous humour


  Jelly-like fluid which helps to keep the shape of the eyeball and also bends the light onto the retina
• Retina


  Layer of light sensitive cells which send impulses to the optic nerve
• Fovea


  Small area of the retina which contains only cones
• Blind spot


  Point at which the optic nerve leaves the eyeball and there is no retina
• Sclera


  Tough, strong outer layer which protects the internal working parts of the eye and has many blood vessels which supply the retina with food and oxygen
• Choroid


  Dark, pigmented layer which absorbs light and stops it being reflected back into the eye
• Cornea


  Clear area of the sclera which helps to bend light onto the retina
• Aqueous humour


  Fluid that fills the front of the eye and helps bend light onto the retina
• Conjunctiva


  Thin clear protective layer over the surface of the eye and lining the eyelids
• Pupil


  The hole in the middle of the iris through which light enters the eye
• Lens


  Clear disc which focuses the light onto the retina - it gives the fine focus
• Suspensory ligaments


  Hold the lens in place and connect it to the ciliary muscles
• Wavelength of violet is 380-450nm
• Wavelength of blue is 450-495nm
• Wavelength of green is 495-570nm
• Wavelength of yellow is 570-590nm
• Wavelength of orange is 590-620nm