A115 Exploration 4: Temperature

In this week’s online segment, we’ll explore infrared light, and what it tells us about the universe. During class, we’ll use an infrared camera to demonstrate how the objects around us glow at wavelengths our eyes cannot see. Objects radiate light depending on their temperatures. Cool objects glow in radio or infrared light, while warmer objects like stars glow in optical light. The hottest objects in the universe glow in ultraviolet, x-ray, and gamma-ray light.

This exploration should take about an hour to complete, the equivalent of one class period. And if you want to play with the infrared camera yourself, please attend one of the scheduled help sessions this week. Be sure to watch the video that is part of this week’s reading assignment.

Learning Goals:

Students should be able to

  • Describe how an object’s thermal emission spectrum depends on temperature.
  • Explain how temperature can be measured using the color of an astronomical source.
  • Explain now astronomers can determine the temperature of astronomical objects using Wien’s Law.

What to Hand In:

This Exploration should be submitted online using the Word form below. Be sure to answer all questions.


Come to one of the Free Help Sessions if you need help with this Exploration. The schedule for help sessions is available in the Syllabus.