black body radiation

• a perfect black body:

  • absorbs all radiation that hits it
  • do not reflect any light or transmit any radiation
  • best possible emitter of radiation
• • stars are black bodies because they are good emitters of most wavelengths in the electromagnetic spectrum
  • so, they absorb most wavelengths
  • planets and black holes are black bodies
• • white and shiny silver surfaces are the worst absorbers of light, as they reflect all visible light wavelengths
  • they are poor emitters and do not emit radiation as quick as darker colours
  • radiations in homes are painted white so infrared radiation is emitted gradually