Blackbody Radiation

A blackbody radiation demo visually proves how objects emit a continuous spectrum of light purely based on their temperature. As an object gets hotter, its emitted radiation increases in total intensity and its peak wavelength shifts from invisible infrared to visible light—progressing from red to orange, yellow, and white

This active demonstration physically maps the relationship between color, temperature, and wavelength using a standard light bulb.

Connect an incandescent bulb to a variable power supply (voltage source) to control the filament's temperature. By turning up the voltage, you increase the current, which heats the filament. At lower voltages, the filament is "cool" and emits mostly infrared heat. As you increase the power, the filament gets hotter and visibly glows dull red, then bright orange, and finally yellow-white.