Annus MirabilisEinstein in 1905
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light quanta

The equation explained

β=4,866⋅10−11.\beta = 4{,}866 \cdot 10^{-11}.
In wordsThe constant β of Planck's formula is 4.866 × 10⁻¹¹, as the paper prints it.OverviewThe second constant of Planck's formula, with the value the paper prints. It sets the frequency, relative to the temperature, at which the spectrum turns over, and the later sections build the size of the energy quantum from it.Full explanationβ\beta stands in the exponent of Planck's formula, as βνT\frac{\beta \nu}{T}, so it sets the scale of frequency, relative to the temperature, at which the exponential takes over. Where βν\beta \nu is small compared with TT the formula goes over into section 1's; where it is large the density falls off. It is the same β\beta from which the later sections build the size of the energy quantum, RNβν\frac{R}{N} \beta \nu. It is the constant of Planck's and Wien's formulas, not the β\beta of the relativity paper.Every stepβ=4,866⋅10−11\beta = 4{,}866 \cdot 10^{-11}The value as printed on p. 136, with the German decimal comma.βνT\frac{\beta \nu}{T}Where it acts: in the exponent of Planck's formula. A frequency ν\nu counts as low when βν\beta \nu is small compared with the temperature TT.Also

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