Wien’s displacement law states that the wavelength at which a blackbody emits most intensely is inversely proportional to its temperature. In simple terms, hotter objects emit peak radiation at shorter wavelengths.
Key insight:
- As temperature increases, the peak of the emission spectrum shifts toward the blue (shorter wavelength) end.
- Cooler objects peak in the infrared, while hotter ones glow red, white, or blue.
Why it matters:
This law helps astronomers determine the surface temperatures of stars by analyzing their color. For example, the Sun (around 5,800 K) peaks in visible light, while hotter stars peak in ultraviolet. It’s a crucial bridge between thermal radiation and temperature measurement in both physics and astronomy.