Marchers in the Key West Pride parade carry a 100-foot-long section of an iconic 1.25-mile-long rainbow flag Sunday, June 11, 2023, up Duval Street in Key West, Fla.

Since its creation in 1978, the Rainbow Pride Flag has become a universal symbol for the LGBTQ community. While the flag's image is well-recognized, its history may not be as well-known.

It takes all the colors of the rainbow for us to see it that way. It happens because of something called the Rayleigh effect, or Rayleigh scattering, named after a British scientist who first ...