TED KINSMAN / SCIENCE PHOTO LIBRARY TED KINSMAN / SCIENCE PHOTO LIBRARY
An iron rod is heated with a torch. The iron in the metal changes colour from red to white as the temperature rises, in a process called thermionic emission of light. The colour of the light given off by the top metal is called the colour temperature. Image 2 in a series of 3.
Model release not required. Property release not required.