Because parahydrogen has nuclei spinning in opposing directions -- both with and against the larger magnetic field of the imager -- its two signals cancel each other out, leaving zero net signal.
The domains point in different directions, confining the field lines to microscopic loops between neighboring domains, so the combined fields cancel at a distance.
Because induced responses may have different phases across measurements and therefore would cancel out during averaging, they can only be obtained using time-frequency analysis.
A dissenting judge was not persuaded by the majority's nuanced distinction between a mere notice of intent to cancel and an actual notice of cancellation in anticipation of default.
