Blackbody Radiation Calculator
Calculate the peak wavelength and total emitted power of a blackbody for a given temperature.
Blackbody Parameters
Blackbody Radiation Laws
A blackbody is an idealized object that absorbs all incident electromagnetic radiation and emits thermal radiation based solely on its temperature.
Wien's Displacement Law:
Where:
- λpeak = Peak Wavelength (meters)
- b = Wien's Displacement Constant (2.898 × 10-3 m·K)
- T = Absolute Temperature (Kelvin)
Stefan-Boltzmann Law:
Where:
- P/A = Total Emitted Power per unit area (W/m2)
- σ = Stefan-Boltzmann Constant (5.67 × 10-8 W·m-2·K-4)
- T = Absolute Temperature (Kelvin)
Blackbody Radiation Examples
| Object | Temperature (K) | Peak Wavelength | Emitted Power (W/m²) |
|---|---|---|---|
| Human Body | 310 K | ~9.35 μm (Infrared) | ~500 W/m² |
| Sun's Surface | 5800 K | ~500 nm (Visible Light) | ~6.4 × 107 W/m² |
| Incandescent Bulb Filament | 2800 K | ~1.03 μm (Infrared) | ~3.5 × 105 W/m² |
Frequently Asked Questions
What is a blackbody?
A blackbody is an idealized physical body that absorbs all incident electromagnetic radiation, regardless of frequency or angle of incidence. It emits thermal radiation in a continuous spectrum that depends only on its temperature, not on its composition or structure.
What is Wien's Displacement Law?
Wien's Displacement Law states that the peak wavelength of emitted radiation from a blackbody is inversely proportional to its absolute temperature. Formula: λ_peak = b / T, where b is Wien's displacement constant (2.898 × 10⁻³ m·K).
What is the Stefan-Boltzmann Law?
The Stefan-Boltzmann Law states that the total energy radiated per unit surface area of a blackbody across all wavelengths per unit time is directly proportional to the fourth power of the blackbody's absolute temperature. Formula: P/A = σT⁴, where σ is the Stefan-Boltzmann constant (5.67 × 10⁻⁸ W·m⁻²·K⁻⁴).