Planck spectrum

Planck s constant, 23 33 Planck spectrum, 23 2 Plan-Do-Check-Act (PDCA) model, 21 174 Plane-polarized light (PPL), 16 470, 476 Planetary rotation reactor, 22 154, 155 Planetary type mixers, 16 720 Plane wall, heat-transfer rate through,... 

The Planck spectrum with linear scales. E in units kT nin units k1T1/c2hi. 

The Planck spectrum with logarithmic scales (m.w microwave i.r infrared vis visible light u.v ultraviolet radiation). 

Total heat transfer consists of radiation at different frequencies. The distribution of radiation energy in a spectrum and its dependency on temperature is determined from Planck s law of radiation. M ,and are the spectral radiation intensities for a blackbody ... 

When Planck used this relationship to calculate the spectrum of blackbody radiation, he came up with a result that agreed perfectly with experiment. More importantly, he had discovered quantum mechanics. Energy emitted by a blackbody is not continuous. Instead, it comes in tiny, irreducible packets or quanta (a word coined by Planck himself) that are proportional to the frequency of the oscillator that generated the radiation. 

Now that we have a simple model for the continuum spectrum of the stars based around the Planck curve, the temperature and the luminosity, we can make some observations and classifications of the stars. There are some constellations that dominate the night sky in both the northern and southern hemispheres and even a casual look should inspire wonder. Star hopping in the night sky should lead to the simplest observation not all stars have the same colour. A high-quality photograph of the constellation of Orion (see page 2 of the colour plate section) shows stars... 

Some important examples of real radiation sources with spectral distributions close to the Planck distribntion are the sun (which shows a spectrum consistent with T = 6000 K) and the bright tnngsten wire of a light bulb T = 2800 K). 

Fig. 3.28. The electron impact mass spectrum of [60]fullerene. The insets show the expanded signals of M, and ions. The signals of the patterns are at 1, 0.5 and 0.33 u distance, respectively. The intensity scale has been normalized in the insets to allow for easier comparison of the isotopic patterns. By courtesy of W. Kratschmer, Max Planck Institute for Nuclear Physics, Heidelberg.

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