  The attractive force between metallic surfaces, predicted by Casimir in 1948,
seems to indicate the physical existence and measurability of the quantized
electromagnetic field's zero-point energy. It is shown in this article, that
the measurements of that force do not confirm Casimir's model, but in fact
disprove it's foundational assumption that metal plates may be represented in
the theory by quantum-field-theoretical boundaries. The consequences for the
cosmological constant problem are discussed.
