How a Power Outage In Colorado Caused US Official Time To Be 4.8 Microseconds (npr.org)
- Reference: 0180441921
- News link: https://science.slashdot.org/story/25/12/23/018200/how-a-power-outage-in-colorado-caused-us-official-time-to-be-48-microseconds
- Source link: https://www.npr.org/2025/12/21/nx-s1-5651317/colorado-us-official-time-microseconds-nist-clocks
> The U.S. government calculates the country's [2]official time using more than a dozen atomic clocks at a federal facility northwest of Denver. But when a [3]destructive windstorm knocked out power to the National Institute of Standards and Technology (NIST) laboratory in Boulder on Wednesday and a backup generator subsequently failed, time ever so slightly slowed down. The lapse "resulted in NIST UTC [universal coordinated time] [4]being 4.8 microseconds slower than it should have been ," NIST spokesperson Rebecca Jacobson said in an email. [...]
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> Since 2007, the official time of the U.S. has been determined by the commerce secretary, who oversees NIST, along with the U.S. Navy. The national time standard is known as NIST UTC. (Somewhat confusingly, UTC itself is a separate, global time standard to which the U.S. and other countries contribute measurements.) NIST currently calculates the standard using a weighted average of the readings of 16 atomic clocks situated across the Boulder campus. Atomic clocks, including hydrogen masers and cesium beam clocks, rely on the natural resonant frequencies of atoms to tell time with extremely high accuracy.
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> All of the atomic clocks continued ticking through the power outage last week thanks to their battery backup systems, according to NIST supervisory research physicist Jeff Sherman. What failed was the connection between some of the clocks and NIST's measurement and distribution systems, he said. Some critical operations staff who were still on site following the severe weather were able to restore backup power by activating a diesel generator the team had kept in reserve, Sherman said.
[1] https://slashdot.org/~Tony+Isaac
[2] https://www.nist.gov/pml/time-and-frequency-division/time-realization/utcnist-time-scale-0/introduction-utcnist
[3] https://www.cpr.org/2025/12/19/nearly-90000-xcel-customers-without-power-friday-morning/
[4] https://www.npr.org/2025/12/21/nx-s1-5651317/colorado-us-official-time-microseconds-nist-clocks
Now the US is officially behind the rest if the wo (Score:3, Funny)
It will probably take a a few years to catch up
Don't leave me hanging! (Score:2)
> How a Power Outage In Colorado Caused US Official Time To Be 4.8 Microseconds
4.8 microseconds what? Longer, shorter - wider, thinner? Unless... (*gasp*) Time is now 4.8 microseconds. /s :-)
Re: (Score:2)
Yeah, I know it's de rigueur to complain about Slashdot's editors, and sometimes that's not really fair. But these mid-sentence title clips are happening more and more often, and it's hard to come up with an explanation other than simple laziness or sloppiness.
Re: Don't leave me hanging! (Score:2)
That's what I understood from the headline!
The time is now: 0:00:00.000 004 8
The time is now: 0:00:00.000 004 8 (Score:2)
Well that solves the problem of Social Security...
Something is wrong with the post's hadline (Score:2)
something seems to be missing
Re:Something is wrong with the post's hadline (Score:4, Funny)
meet the new slashdot editor: clippy
Re: Something is wrong with the post's hadline (Score:2)
Does AI do English grammar better than any human?
It's official (Score:2)
The USA really is going back in time compared to the rest of the world. And here I thought that was just a joke we made about Trump and his policies.
Just declare it "correct" (Score:2)
"Freedom time"
Our professional timekeepers (Score:2)
I just love that a bunch of people immediately just went to work when the power went out.
"How's clock number five?"
"Not sure, but eleven and twelve are holding. We seem to be losing synchronization."
"We can't lose NIST UTC!! Don't we have that generator in the back?"
This is a _very_ big deal! (Score:5, Insightful)
NIST have always been the world leader in creating ever more accurate clocks, the current masers work in picoseconds and below, so allowing the reference to drift by 4.8 microseconds means that precision dropped by at least 6 orders of magnitude.
If allowed to propagate to the GPS control clocks, this would have been enough to totally destroy the navigation system since a clock that is off by 4.8 us corresponds to a position error of 1500 kilometers. (OTOH, USNO has its own large ensemble of atomic clocks, so they don't depend short term on NIST updates.)
Full disclosure: I worked with the NTP Hackers (network time protocol) team for 20+ years, so I'm probably a bit more interested in precise timekeeping than most. I have personally soldered together 4 or 5 GPS-based reference clocks that would deliver 25-35 ns RMS precision.
What failed was the connection between some of the (Score:2)
Ok, some clocks were disconnected. But why haven't the remaining clocks been accurate enough? Shouldn't even a single clock suffice? It sounds like the time is only accurate if an average of all clocks can be calculated.
Cause and Effect. (Score:2)
> But when a destructive windstorm knocked out power to the National Institute of Standards and Technology (NIST) laboratory in Boulder on Wednesday and a backup generator subsequently failed, time ever so slightly slowed down.
Its not that I’m chastising NIST backup capability as much as I’m shocked that is the steps it takes to hobble one of the country’s most critical services.
Then again, what exactly was the impact? Good time to bolster recovery processes if there is a measurable one I guess. Doesn’t happen very often.
Re: (Score:2)
I am actually shocked. As claimed by the article, it's not the clocks themselves that were compromised, it's actually the network outage that caused the problem.
That makes sense, because the time protocol requires estimating routing delays, so when the outage happened there may have been a change to the estimated delays in the network. And that seems frankly ridiculous, if true, since there's no reason that the network relaying the atomic clock readings should be tampered with on an ordinary operating day
Re: (Score:2)
Not so. We have moved on from such large time uncertainties in networking in the last 10 years, at least for specialized applications.
Also do not confuse the reference clock being slow, and the time propagation across the global network (ie Internet) being slow.
It is fine for the NIST clock to be inaccessible to the wider network for small periods of time, which would inevitably introduce drift on the downstream systems. Once those systems reconnect to NIST, they could correct themselves.
What is not f