Quantum Physics in Your Kitchen

While ubiquitous quantum computers may seem far off, quantum principles are already at work in many technologies available today.

A common kitchen appliance demonstrates one of the phenomena that led to the founding of quantum science: Inside our toasters, there are metallic elements that glow red when they heat up. Heat any material to the same temperature and the same thing will happen: if you get them hot enough, all materials, metal or not, will glow red, then yellow, then white as they get hotter. This observation provided insight into the field of quantum science. Physicists in the late 1800s and early 1900s proposed that energy emitted from these heated elements was restricted to certain wavelengths, each producing a different visible color. This restricted range is due to the fact that light delivers energy in discrete packets, or “quanta.”

Interested in more examples? Hint: one is probably in your office ceiling, and another is in your phone. Visit the Caltech Science Exchange and click on the toaster.