What is Wien's displacement constant?
Wien's wavelength displacement constant is b = 2.897771955e-3 m·K, exact by SI definition. It gives the blackbody peak: λ_max·T = b.
Open the interactive PhysRef tool →Key facts
| Value | 2.897771955e-3 m·K |
|---|---|
| Symbol | b |
| Law | λ_max = b / T |
| Exactness | Exact by SI definition (uncertainty 0) |
| Source | CODATA 2018 |
Frequently asked questions
What is the value of Wien's displacement constant?
b = 2.897771955e-3 m·K, relating a blackbody's peak wavelength to its temperature.
What is Wien's displacement law?
The peak emission wavelength satisfies λ_max = b/T, so hotter bodies peak at shorter wavelengths.
What is the peak wavelength of the Sun?
For the Sun's ~5778 K surface, λ_max ≈ b/T ≈ 502 nm, in the green part of the visible spectrum.
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