Blackbody Radiation Calculator
Calculate peak emission wavelength using Wien's displacement law.
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Enter the temperature of the object in Kelvin. The calculator uses Wien's displacement law to find the peak emission wavelength. Results are shown in both nanometers and meters, along with the spectral region.
About Blackbody Radiation
Every object above absolute zero emits thermal radiation. A blackbody is an ideal emitter whose radiation spectrum depends only on temperature. Wien's displacement law gives the wavelength at which emission intensity is maximum. This principle is used in astrophysics to estimate star temperatures, in thermal imaging, and in designing lighting and heating systems. The Sun, at roughly 5,778 K, peaks near 500 nm in the visible green spectrum.
Frequently Asked Questions
What is blackbody radiation?
A blackbody is an idealized object that absorbs all incident radiation and re-emits it based solely on its temperature. The spectrum of emitted radiation depends only on temperature, not material properties.
What is Wien's displacement law?
Wien's law states that the peak wavelength of blackbody emission is inversely proportional to temperature. The constant b is approximately 2.898 x 10^-3 m K. Hotter objects emit at shorter wavelengths.
Why is the Sun's peak wavelength in the visible spectrum?
The Sun's surface temperature of about 5,778 K produces a peak emission wavelength near 502 nm, which falls in the visible green range. This is why human eyes evolved to be most sensitive to visible light.