Chromatic Dispersion in a Prism

Yes! Chromatic dispersion takes place as light crosses the boundary between one transparent medium and another if it has a different refractive index.

Yes! Every wavelength of light is affected to a different degree by the refractive index of a transparent medium and as a result, changes direction by a different amount when passing from air to glass or glass to air.

Chromatic dispersion refers to the way that light separates into its component wavelengths (and so colours), under certain conditions.

Every wavelength of light is affected to a different degree by the refractive index of a material and as a result changes direction by a different amount when passing from one medium (such as air) to another (such as glass or water).

Yes! Light separates into different colours during the course of refraction.

A light source is a natural or man-made object that emits one or more wavelengths of light.

• The Sun is the most important light source in our lives and emits every wavelength of light in the visible spectrum.
• Celestial sources of light include other stars, comets and meteors.
• Other natural sources of light include lightning, volcanoes and forest fires.
• There are also bio-luminescent light sources including some species of fish and insects as well as types of bacteria and algae.
• Man-made light sources of the most simple type include natural tars and resins, wax candles, lamps that burn oil, fats or paraffin and gas lamps.
• Modern man-made light sources include tungsten light sources. These are a type of incandescent source which means they radiate light when electricity is used to heat a filament inside a glass bulb.
• Halogen bulbs are more efficient and long-lasting versions of incandescent tungsten lamps and produce a very uniform bright light throughout the bulb’s lifetime.
• Fluorescent lights are non-incandescent sources of light. They generally work by passing electricity through a glass tube of gas such as mercury, neon, argon or xenon instead of a filament. These lamps are very efficient at emitting visible light, produce less waste heat, and typically last much longer than incandescent lamps.
• An LED (Light Emitting Diode) is an electroluminescent light source. It produces light by passing an electrical charge across the junction of a semiconductor.
• Made-made lights can emit a single wavelength, bands of wavelengths or combinations of wavelengths.
• An LED light typically emits a single colour of light which is composed of a very narrow range of wavelengths.

An additive colour model explains how different coloured lights (such as LEDs or beams of light) are mixed to produce other colours.

• Additive colour refers to the methods used and effects produced by combining or mixing different wavelengths of light.
• The RGB colour model and HSB colour model are examples of additive colour models.
• Additive colour models such as the RGB colour model and HSB colour model can produce vast ranges of colours by combining red, green, and blue lights in varying proportions.
• An additive approach to colour is used to achieve precise control over the appearance of colours on digital screens of TVs, computers, and phones.

Rainbow colours are the colours seen in rainbows and in other situations where visible light separates into its different wavelengths and the spectral colours corresponding with each wavelength become visible to the human eye.

• The rainbow colours (ROYGBV) in order of wavelength are red (longest wavelength), orange, yellow, green, blue and violet (shortest wavelength).
•  It is the sensitivity of the human eye to this small part of the electromagnetic spectrum that results in our perception of colour.
• The names of rainbow colours are a matter more closely related to the relationship between perception and language than anything to do with physics or scientific accuracy. While the spectrum of light and the colours we see are both determined by wavelength, it’s our eyes and brains that turn these differences in light into the colours we experience.
• In the past, rainbows were sometimes portrayed as having seven colours: red, orange, yellow, green, blue, indigo and violet.
• Modern portrayals of rainbows reduce the number of colours to six spectral colours, ROYGBV.
• In reality, the colours of a rainbow form a continuous spectrum and there are no clear boundaries between one colour and the next.

 

 

The angle of refraction measures the angle to which light bends as it passes across the boundary between different media.

• The angle of refraction is measured between a ray of light and an imaginary line called the normal.
• In optics, the normal is a line drawn on a ray diagram perpendicular to, so at a right angle to (90⁰), the boundary between two media.
• See this diagram for an explanation: Refraction of a ray of light
• If the boundary between the media is curved, the normal is drawn perpendicular to the boundary.

Visible light refers to the range of wavelengths of electromagnetic radiation that is perceived as colour by human observers. While the range of visible light is generally considered to be 400-700 nm, the exact range of colours perceptible can vary slightly between individuals.

• Visible light is one form of electromagnetic radiation. Other forms of electromagnetic radiation include radio waves, microwaves, infrared, ultraviolet, X-rays, and gamma rays. Visible light ranges from approximately 400 nanometres (nm) for violet to 700 nm for red.
• A human observer perceives visible light as a combination of all the spectral colours between red and violet, as well as a vast range of other colours produced from the blending of different wavelengths in varying proportions.

A colour model is a system or framework used to understand, organise, and manipulate colour. It ranges from basic concepts, such as the sequence of colours in a rainbow, to more advanced models like RGB, CMYK, and CIE, which are essential for accurate colour reproduction in various fields, including digital media, printing, and manufacturing.

• A colour model, underpinned by colour theory, provides a precise and replicable approach to understanding:
  • How the human eye perceives light and interprets colour.
  • Different types of colour, including those produced by mixing lights, pigments, or inks.
  • How to manage the diverse ways colour is processed by devices such as cameras, digital screens, and printers.
• Colour models enable us to:
  • Make sense of colour in relation to human vision and the world around us.
  • Use colours in logical, predictable, and replicable ways.
  • Understand how to mix specific colours, whether using lights, pigments, inks, or dyes.
  • Specify colours using names, codes, notations, or equations.
  • Organise and apply colour for different purposes, from fabrics and interiors to vehicles.

• For more information see https://lightcolourvision.org/dictionary/definition/colour-model/

Refraction refers to the way that electromagnetic radiation (light) changes speed and direction as it travels across the boundary between one transparent medium and another.

• Light bends towards the normal and slows down when it moves from a fast medium (like air) to a slower medium (like water).
• Light bends away from the normal and speeds up when it moves from a slow medium (like diamond) to a faster medium (like glass).
• These phenomena are governed by Snell’s law, which describes the relationship between the angles of incidence and refraction.
• The refractive index (index of refraction) of a medium indicates how much the speed and direction of light are altered when travelling in or out of a medium.
• It is calculated by dividing the speed of light in a vacuum by the speed of light in the material.
• Snell’s law relates the angles of incidence and refraction to the refractive indices of the two media involved.
• Snell’s law states that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is equal to the ratio of the refractive indices.

In physics and optics, a medium refers to any material through which light or other electromagnetic waves can travel. It’s essentially a substance that acts as a carrier for these waves.

• Light is a form of electromagnetic radiation, which travels in the form of waves. These waves consist of oscillating electric and magnetic fields.
• The properties of the medium, such as its density and composition, influence how light propagates through it.
• Different mediums can affect the speed, direction, and behaviour of light waves. For instance, light travels slower in water compared to a vacuum.
• Examples of Mediums:
  • Transparent: Materials like air, glass, and water allow most light to pass through, with minimal absorption or scattering. These are good examples of mediums for light propagation.
  • Translucent: Some materials, like frosted glass or thin paper, partially transmit light. They allow some light to pass through while diffusing or scattering the rest.
  • Opaque: Materials like wood or metal block light completely. They don’t allow any light to travel through them.

Optical density is a measure of how much a material resists and slows the transmission of light.

• The higher the optical density of a material, the slower light travels through it.
• The lower the optical density of a material, the faster light travels through it.
• A vacuum is not a medium and has zero optical density.
• Light travels through a vacuum at the maximum possible speed of light which is 299,792 kilometres per second.
• Optical density and refractive index are related properties.
• In general, materials with higher optical density tend to have higher refractive indices and vice versa.
• The greater the difference in refractive index between two materials, the more they will bend light when they come into contact.