Visible light & Colour

• What is the main topic of today's video?

  The color appearance of objects
• What is visible light composed of?

  A spectrum of different colors
• Which color has the longest wavelength?

  Red
• Which color has the shortest wavelength?

  Violet
• What acronym can help remember the order of colors in the visible spectrum?

  Roy G. Biv
• Why are white and black not considered colors in the visible spectrum?

  White light is a combination of all wavelengths, while black is the absence of light
• What determines the color an object appears to be?

  The wavelengths of light hitting it and the properties of the object
• What are opaque objects?

  Objects that do not transmit any light
• How does a gas appear blue?

  It reflects blue wavelengths of light and absorbs others
• Why might a piece of cheese appear yellow?

  It reflects yellow wavelengths or a combination of red and green wavelengths
• What is the difference between transparent and translucent objects?

  Transparent objects transmit nearly all light, while translucent objects transmit some light
• How do transparent objects like glass appear?

  They are almost completely see-through because they transmit nearly all light
• How does the color of a translucent object like a plastic bottle get determined?

  By which wavelengths are transmitted most
• Why does a green bottle appear green?

  Because it transmits green wavelengths while absorbing others
• What is the function of color filters?

  To filter out particular colors so that only certain wavelengths can pass through
• What is a primary color filter?

  A filter that only allows one of the three primary colors to be transmitted
• What happens when white light passes through a green filter?

  Only the green wavelength gets through
• How would white paper appear when viewed through a green filter?

  It would appear green because only the reflected green waves would pass through
• What would happen to a blue object viewed through a green filter?

  It would appear black because the filter blocks blue light
• What do yellow filters allow to pass through?

  Yellow light, as well as red and green wavelengths
• What do indigo filters allow to pass through?

  Indigo wavelengths, as well as blue and red wavelengths
• What are the key points about how objects appear in terms of light interaction?

  • Color appearance depends on light wavelengths and object properties.
  • Opaque objects absorb or reflect all light.
  • Transparent objects transmit nearly all light.
  • Translucent objects transmit some light, affecting visibility.
  • Color filters transmit specific wavelengths while absorbing others.
• What are the differences between opaque, transparent, and translucent objects?

  • Opaque: Do not transmit light; color determined by reflected light.
  • Transparent: Transmit nearly all light; clear visibility.
  • Translucent: Transmit some light; visibility depends on light transmission.
• How do primary color filters function?

  • Allow only one primary color to pass through.
  • Block other colors.
  • Example: Green filter allows green light, blocking red and blue.
• How do non-primary color filters work?

  • Allow their color and combinations of primary colors.
  • Example: Yellow filters allow yellow, red, and green light.
  • Example: Indigo filters allow indigo, blue, and red light.