Recently, Boulder faced a power outage that affected the operations of the National Institute of Standards and Technology (NIST) Internet Time Service. Xcel Energy proactively shut off power in advance of hurricane-force winds to mitigate fire risks across Colorado. This decision resulted in a very brief disruption of the NIST F-4 atomic clock, renowned for its precision.
Boulder Power Outage Affects Atomic Clock
The NIST F-4 atomic clock relies on cesium atoms for measuring time accurately. It serves vital industries such as GPS, telecommunications, and scientific research, necessitating ultra-precise timekeeping.
The NIST F-4 Clock
- The NIST F-4 clock utilizes a fountain design, recognized globally for its accuracy.
- Since its inception in 1967, cesium atoms have been the basis for defining a second.
- If it had started tracking time 100 million years ago, it would only be off by less than a second today.
In 2014, NIST introduced the NIST F-2 atomic clock in Boulder, and a new NIST F-4 clock was activated earlier this year at the Department of Commerce site.
Impact of the Power Disruption
On Wednesday, as power was interrupted, the NIST Internet Time Service switched to a backup generator. However, a brief lapse in power resulted in a drift of about 4 microseconds in NIST UTC time. NIST spokesperson Rebecca Jacobson noted that this drift translates to four millionths of a second.
Comparison of Time Drift
- 350,000 microseconds: Time taken to blink.
- 150,000 microseconds: Time taken to snap fingers.
For most users, the drift remained undetectable. However, industries like telecommunications and aerospace, where precise timing is crucial, were alerted in advance. NIST offers access to alternative networks to ensure continuity during such outages.
Jacobson assured that the impact on the time service is minimal due to a network of clocks and servers distributed across various locations. Currently, the Boulder site’s power remains offline, with plans to recalibrate the clock and rectify the drift once service is restored.
