Blackbody radiation refers to the electromagnetic radiation that is emitted by a perfectly black object, which absorbs all incoming radiation without reflecting any. This phenomenon was first described by Max Planck in 1900, when he introduced the concept of quantized energy. According to Planck's law, the spectral radiance of a blackbody at a given wavelength and temperature can be calculated using the following formula:

\[ B(\lambda, T) = \frac{2 h c^2}{\lambda^5} \frac{1}{e^{\frac{hc}{\lambda kT}} - 1} \]

where:
- B(λ, T) is the spectral radiance at wavelength λ and temperature T,
- h is the Planck constant,
- c is the speed of light,
- λ is the wavelength of the radiation,
- k is the Boltzmann constant, and
- T is the temperature of the blackbody.

This formula shows that the spectral radiance of a blackbody depends on both the temperature of the object and the wavelength of the radiation. As the temperature of the blackbody increases, the peak of the spectral radiance shifts towards shorter wavelengths according to Wien's displacement law. This means that hotter objects emit more radiation at higher frequencies.

In addition to spectral radiance, other important parameters that are used to describe blackbody radiation include the total radiance (given by the Stefan-Boltzmann law) and the Wien displacement law. The Stefan-Boltzmann law states that the total radiance (also known as the total power emitted per unit area) of a blackbody is proportional to the fourth power of its temperature:

\[ P = \sigma T^4 \]

where:
- P is the total radiance,
- σ is the Stefan-Boltzmann constant, and
- T is the temperature of the blackbody.

Wien's displacement law, on the other hand, states that the wavelength at which the spectral radiance of a blackbody is maximum (known as the peak wavelength) is inversely proportional to the temperature of the object:

\[ \lambda_{max} = \frac{b}{T} \]

where:
- λmax is the peak wavelength,
- b is Wien's displacement constant, and
- T is the temperature of the blackbody.

Blackbody radiation is a fundamental concept in physics and plays a crucial role in many areas of science, including astrophysics, thermal imaging, and spectroscopy. By studying the theoretical data of blackbody radiation, scientists are able to better understand the behavior of objects at different temperatures and wavelengths, leading to advancements in technology and a deeper understanding of the universe.