Light

• Light


  An electromagnetic wave that does not need a medium to propagate, travels in a straight path in vacuum, and has a speed of 299,792,458 m/s
• Photons


  The smallest unit of visible light
• Luminous body


  An object capable of producing its own light
• Natural sources of light


  • Sun
• Artificial sources of light

  • Lamps
  • Bulbs
  • Candles
• Scientists who contributed to understanding light

  • Isaac Newton
  • Christian Huygens
  • Louis de Broglie
  • James Clerk Maxwell
• Dual nature of light


  Light behaves as both particles (photons) and waves
• Electromagnetic spectrum


  Arrangement of electromagnetic waves in increasing frequency
• Radio waves have the lowest frequency, and gamma rays have the highest frequency in the electromagnetic spectrum
• Visible light spectrum


  The only frequency of electromagnetic waves visible to the human eye
• Dispersion


  The phenomenon where a prism separates white light into its component colors
• Component colors of white light

  • Red
  • Orange
  • Yellow
  • Green
  • Blue
  • Indigo
  • Violet
• Properties of light


  • Wavelength
  • Frequency
  • Amplitude
• Light intensity


  The power of light, the quantity that measures the amount of light illuminating a surface
• Photometry


  The science of measuring the intensity or brightness of light
• Brightness


  The visual perception of the amount of light emitted or reflected by a surface
• Luminous intensity


  The amount of light an object produces, measured in candela
• Distance from the light source


  Affects the brightness of the light
• Amplitude of light waves


  Affects the brightness of the light
• Visible light spectrum


  Wavelength range of 400 to 750 nanometers
• Ultraviolet


  Electromagnetic waves with wavelengths shorter than 400 nanometers
• Infrared


  Electromagnetic waves with wavelengths greater than 750 nanometers
• Wavelength and frequency of light


  As wavelength increases, frequency decreases
• Colors in the visible light spectrum


  • Red
  • Orange
  • Yellow
  • Green
  • Blue
  • Indigo
  • Violet
• White light is the combination of all wavelengths of visible light, and black is the absence of wavelength
• Light


  travels in a straight path

  made if photons

  it does not need medium to propagate

  electromagnetic wave
• Isaace Newton


  "light behaves like a particle"
• Christian Huygens


  Light behaves like a wave
• Louie De Broglie


  Light can be a particle and a wave
• James Clerk Maxwell


  Electromagnetic theory of light
• Visible light spectrum


  aka White Light
• Visible Light


  Only seen by the naked eye
• Photometry


  The science of measuring the intensity or brightness of light
• Brightness


  A qualitative expression of light intensity
• Visible Light


  Visible light falls in the wavelength range ofof 400 manometers to 750 manometers
• White and Black


  The color white represents the combination of all wavelength of visible light;while black isis the absence of the wavelength