Sarum College, 19 The Close, Salisbury, U.K., SP1 2EE
Speaker: Charles Baynham, National Physical Laboratory
The SI unit system, the bricks upon which science is built, will soon be redefined: moving away from a dependence on physical artefacts to a system that is directly defined by the fundamental constants of nature. Within this new system, time takes a crowning role, appropriately since modern atomic clocks are the most accurate instruments ever created.
One of those extraordinary instruments is the ytterbium optical clock at the UK’s National Physical Laboratory, a device which uses a single atom to measure the duration of the second. In this device, a forbidden transition in a laser-cooled trapped ion is excited, and the frequency of the light causing this excitation sets the rate at which the clock ‘ticks’.
This talk will focus on how this works, the ingredients of any atomic clock and some of the physics which becomes possible when you have a machine that operates at the 18th decimal place, a point at which the edges of the Standard Model may begin to fray.
- Wheelchair access
- Car park
- Coffee and Tea from 19:00
Image: UK National Physical Laboratory