Summary: Vol 441|18 May 2006
Do water molecules weave webs or just spin
threads? The traditional picture of water
has each molecule linked, on average,
tetrahedrally to four others in a hydrogen-
bonded network. But this model was
challenged two years ago by spectroscopic
measurements suggesting that the molecules
have on average only two hydrogen-bonded
neighbours, linking them in chains.
Using X-ray scattering, which probes a
wide range of length scales, Teresa Head-
Gordon and Margaret Johnson at the
University of California, Berkeley, now offer
a conciliatory resolution to the controversy.