physics 7.4

• Refraction is the appearance of light bending when it moves from one medium to another
• When light passes from a denser medium to a rarer medium, it bends away from the normal
• Ray diagram of refraction:

  • Incident ray: the ray of light before it enters the medium
  • Refracted ray: the ray of light after it passes through the medium
  • Normal: an imaginary line drawn perpendicular to a surface or medium
• The speed of light is faster in mediums with particles further apart, like air, and slower in mediums with particles closer together, like water or solids
• Refraction occurs when a light ray passes from one medium to another, causing the light ray to change direction and speed.
• Examples of refraction include:

  • Objects appearing to bend in water
  • Formation of a rainbow
  • swimming pool appearing shallow
• The refractive index (R.I) not only tells you how fast light travels in a medium but also how dense the medium is
• In refraction, a high refractive index indicates that the speed of light is slow and the medium is denser, while a low refractive index means fast speed of light and a rarer medium
• The speed of light can be measured in m/s (meters per second)
• Refraction of light occurs when light travels from one medium to another, changing its direction, speed, and medium.
• The bending of light starting at the boundary between two mediums, is called refraction
• The angle between the normal and the incident ray is the angle of incidence, while the angle between the ray and the normal on the other side of the boundary (between refracted ray and normal) is the angle of refraction
• When light goes from a rarer medium to a denser medium, like from air to water, the light ray will bend towards the normal
• If light goes from a more dense medium to a less dense medium, like from water to air, then it will bend away from the normal
• Real depth is the actual depth of an object, while apparent depth is how deep it appears due to refraction
• Refraction explains why a pool looks shallower than it actually is (real depth and apparent depth; the bottom appears to be above, where the real depth is deeper)
• The speed of light varies in different mediums; an optically denser medium will cause light slow light down more, causing more refraction
• a recractive index of a medium is defined by the speed of light in air or a vacuum divided by the speed of light in the given medium
• The refractive index is higher if light slows down more; for example, diamond has a refractive index of 2.4, causing more refraction than glass with a refractive index of 1.5