Spectators dance in the infield before the 150th running of the Kentucky Derby at Churchill Downs in Louisville, KY on Saturday, May 04, 2024. (Photo by Jabin Botsford/The Washington Post)

Mr. Zhong Hua, of Johns Hopkins University School of Medicine, took this image of the peripheral nerves (those outside of the brain) in an 11.5-day-old mouse embryo, magnified five times. (Photo by Zhong Hua)