A cross-section of skeletal muscle in this light micrograph shows the individual, parallel muscle fibers (red). These fibers work in concert to power movement. Thomas Deerinck, NCMIR/ScienceSource hide caption

itoggle caption Thomas Deerinck, NCMIR/ScienceSource

Whether the error in Supreme Court Justice Antonin Scalia's recent dissent was originally his fault or a clerk's doesn't make it less cringeworthy. Alex Wong/Getty Images hide caption

itoggle caption Alex Wong/Getty Images

Wild bees, such as this Andrena bee visiting highbush blueberry flowers, play a key role in boosting crop yields. Left photo by Rufus Isaac/AAAS; Right photo courtesy of Daniel M.N. Turner hide caption

itoggle caption Left photo by Rufus Isaac/AAAS; Right photo courtesy of Daniel M.N. Turner

Tornadoes killed at least 17 people on Sunday and Monday. But some managed to stay safe in underground shelters like the one at right in Vilonia, Ark. Karen E. Segrave/AP hide caption

itoggle caption Karen E. Segrave/AP