Understanding Deviations in Wien's Law for Long Wavelengths

[nonequilibrium]

While Wien's law was confirmed for small values of energy, i.e. for short waves, O Lummer and E Pringsheim found large deviations in the case of long waves.

In his nobel laureate speech.

I thought "small values of energy" <=> "long wavelengths"? And for a body of a low temperature T, the maximum is for long wavelengths, so it can't be that either.

What did he maen?

 

[D H]

Planck spoke German, not English. This is a mistranslation / misinterpretation of his speech. Here's the translation at the Nobel Prize site, http://nobelprize.org/nobel_prizes/physics/laureates/1918/planck-lecture.html

Whilst for small values of the energy and for short waves, Wien's law was satisfactorily confirmed, noteworthy deviations for larger wavelengths were found, ...​

Note the use of "and" rather than "i.e.".

Wien's law describes the spectrum of black body radiation. While it is accurate at short wave lengths (high frequencies), it is not accurate at low frequencies. Wien's law is a good approximation for black bodies that are radiating a relatively small amount of total energy. When the total energy output gets larger, the failure of Wien's law to predict contributions by low frequency waves becomes apparent.

 

[nonequilibrium]

Thank you! :)