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

False-color transmission electron micrograph of a field of whooping cough bacteria, Bordetella pertussis. A. Barry Dowsett/Science Source hide caption

itoggle caption A. Barry Dowsett/Science Source

Writer Jeff Kluger speaking at TEDxAsheville. Courtesy of TED hide caption

itoggle caption Courtesy of TED

Psychotherapist Esther Perel says a good and committed relationship draws on the conflicting needs of security and surprise. Courtesy of TED hide caption

itoggle caption Courtesy of TED

Anthropologist Helen Fischer explains how our brains behave when we're in love. Andrew Heavens/Courtesy of TED hide caption

itoggle caption Andrew Heavens/Courtesy of TED

Amy Webb explains how she found love with some help from algorithms. Ryan Lash/Courtesy of TED hide caption

itoggle caption Ryan Lash/Courtesy of TED

Dr. Timothy Jay says children are like "little language vacuum cleaners" that pick up whatever they hear. iStockphoto.com hide caption

itoggle caption iStockphoto.com

This mouse egg (top) is being injected with genetic material from an adult cell to ultimately create an embryo — and, eventually, embryonic stem cells. The process has been difficult to do with human cells. James King-Holmes/Science Source hide caption

itoggle caption James King-Holmes/Science Source

It's the Sichuan peppercorn in dishes like spicy ma po tofu that makes your mouth buzz. Researchers wanted to know if that buzz is connected to the tingling you feel when your foot falls asleep. iStockphoto hide caption

itoggle caption iStockphoto