Three-dimensional bronze cam representing the equation of time as it evolves over the next 10,000 years, taking into account the Earth's precessional cycle as well as its slowing rotational speed. This is one of a small set of cams manufactured for the first prototype of the 10,000-year mechanical 'Clock of the Long Now', completed in 1999.
The cam retains the original casting marks at its ends.

The Clock of the Long Now is a project conceived by Stewart Brand and Danny Hillis to address a perception that ‘civilization is reviving itself into a pathologically short attention span’. An all-mechanical clock that can survive for 10,000 years is one such attempt to prompt conversations about long-term thinking.