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<jats:p>A team of theorists reported at the American Physical Society meeting that a film of ice only two molecules thick may form the oddest of all crystalline structures, a so-called quasicrystal, which lacks the exact repeatability of an ordinary crystal structure but preserves other symmetries of a crystal.</jats:p>

<jats:p>Snapshots from the American Physical Society meeting include lowering the energy of a vibrating widget enough to achieve the least motion allowed by quantum mechanics—the so-called ground state of motion—and a network model that demonstrates that if 10% of the members of a group hold an unshakable conviction, their view will eventually win out.</jats:p>

<jats:p>While erasing information, a tiny system can sometimes generate less than the minimum amount of heat required by a principle of thermodynamics, physicists reported at the American Physical Society meeting.</jats:p>

<jats:p> Gibbs <jats:italic>et al</jats:italic> . question our reconstruction of surface- and deepwater acidification around Oceanic Anoxic Event 1a. We answer their criticisms to better substantiate our arguments and original conclusions. Contrary to their suggestion, preservation cannot explain the nannofossil changes we documented, which trace perturbations in the photic zone, including a substantial increase in partial pressure of CO <jats:sub>2</jats:sub> ( <jats:italic>p</jats:italic> CO <jats:sub>2</jats:sub> ) and an inferred decreased pH as derived from geochemical proxies. </jats:p>

<jats:p> Erba <jats:italic>et al</jats:italic> . (Reports, 23 July 2010, p. 428) attributed calcareous nannofossil morphology and assemblage changes across Cretaceous Oceanic Anoxic Event 1a to the effects of surface ocean acidification. We argue that the quality of carbonate preservation in these sequences, the unsupported assumptions of the biotic response to acidity, and the absence of independent proxy estimates for ocean pH or atmospheric <jats:italic>p</jats:italic> CO <jats:sub>2</jats:sub> render this conclusion questionable. </jats:p>