Cesium Fountain Atomic Clock Tour - Atlas Obscura

Boulder, Colorado

Cesium Fountain Atomic Clock Tour

Bring your pathetic wristwatch and vainly compare it to its CLOCK MASTER!

Four years to build. Ten times more accurate than its predecessor. One of a handful of clocks used to define Coordinated Universal Time (UTC), the official world time.  So accurate that it will neither lose nor gain a second in more than 100 million years...

Join Atlas Obscura Denver on a tour of the NIST-F1 Cesium Fountain Atomic Clock. If you only recognize a handful of those words, don't sweat! We'll get an in-depth but layman-friendly explanation of how this clock uses lasers to roll atoms into a ball of optical molasses!


  • We need the names of each attendee, so if you're buying multiple tickets, please provide names and emails for each member of your group (you'll be prompted to do so in the order form).
  • Please arrive at least 15 minutes before the tour to check in. The tour will start promptly!
  • Meet at the NIST Lab in Boulder (address in confirmation email). Look for the Atlas Obscura sign.
  • This event is appropriate for ages 10+


Email james.oneill@atlasobscura.com.

Stay connected! Subscribe to the Atlas Obscura Society Denver newsletter  for a first glimpse at upcoming events.

Advance Tickets Only. All Sales Final. No Refunds or Exchanges.