UNSURPRISINGLY, Frank Keppler and Thomas Röckmann's February article on the discovery of methane emissions in plants elicited strong reactions. Although some correspondents seemed eager to jump to the exact global warming--denying conclusions Keppler and Röckmann had cautioned against, others expressed a more thoughtful attitude as to how this discovery might affect our understanding of global climate change. Readers were also drawn to the more cosmic implications of Christopher J. Conselice's overview of how scientists believe dark energy shapes the universe. Many were unsatisfied with our inability to detect such a force from anything but its effects and offered their own theories as to what dark energy might tangibly represent or how the universe could function without it.