Investigating Emission

• Leslie Cube


  A hollow, watertight, metal cube made of e.g. aluminium, whose four vertical faces have different surfaces (for example, matt black paint, matt white paint, shiny metal and dull metal)
• Investigating IR radiation emitted by different surfaces using a Leslie Cube

  1. Place an empty Leslie cube on a heat-proof mat

  2. Boil water in a kettle and fill the Leslie cube with boiling water

  3. Wait for the cube to warm up, then hold a thermometer against each of the four vertical faces of the cube

  4. Hold an infrared detector a set distance (e.g. 10 cm) away from one of the cube's vertical faces, and record the amount of IR radiation it detects

  5. Repeat this measurement for each of the cube's vertical faces, positioning the detector at the same distance from the cube each time
• You should find that you detect more infrared radiation from the black surface than the white one, and more from the matt surfaces than the shiny ones
• It's important to be careful when you're doing this experiment. Don't try to move the cube when it's full of boiling water - you might burn your hands. And take care if you're carrying a full kettle too