Wien's Displacement Law

Wien’s displacement law tells you where a blackbody spectrum reaches its strongest emission: hotter objects peak at shorter wavelengths, while cooler objects peak at longer wavelengths. This happens because increasing temperature shifts the distribution of thermal radiation toward higher-energy photons, so the whole curve moves left as temperature rises. The constant b sets the scale of that inverse relationship and comes from the shape of the blackbody spectrum itself.

Use this when you want to estimate the peak wavelength of thermal radiation from a star, planet, furnace, or any object that behaves approximately like a blackbody. It is especially useful for linking an object’s temperature to the part of the electromagnetic spectrum where it emits most strongly.

• Using the temperature in °C instead of converting to kelvin first
• Confusing the peak wavelength with the wavelength where the object emits the most total energy
• Forgetting that the result is an approximation for a blackbody or near-blackbody, not every real object