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Blackbody Spectrum


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PhET Interactive Simulations
University of Colorado Boulder


  • Blackbody
  • Sun
  • Light
  • Quantum Mechanics


How does the blackbody spectrum of the sun compare to visible light? Learn about the blackbody spectrum of the sun, a light bulb, an oven, and the earth. Adjust the temperature to see the wavelength and intensity of the spectrum change. View the color of the peak of the spectral curve.

Sample Learning Goals

  • Describe what happens to the blackbody spectrum as you increase the temperature. What happens to the shape of the curve and the peak of this curve?
  • What happens to the blackbody spectrum as you decrease the temperature?
  • Set the temperature to that of a light bulb (around 3000 K). Based on this information, do lightbulbs seem efficient? Why do light bulbs get hot?
  • Imagine that you see 2 hot, glowing objects--one is glowing orange and the other is glowing blue. Which one is hotter?
Version 2.02