Nothing lasts forever, not even scientific ideas. One idea that has been around for >70 years is Cholodny–Went's hypothesis of gravitropism. This proposes that the differential growth characteristic of the gravitropic response is brought about principally by the lateral redistribution of the plant growth regulator, auxin. This view has been challenged by Hans Edelmann [Physiol. Plant. 112 (2001) 119–126]. Edelmann's model proposes a gravi-stimulated, temporary inhibition of release of wall-loosening factors on the non-growing side of the organ, which is not dependent upon a redistribution of auxin. Will Cholodny–Went stand the ‘test of time’? Or will its view of gravitropism now fall? NC