NIST Ion Clock Sets New Record for Most Accurate Clock in the World

Re:NIST Ion Clock Sets New Record for Most Accurate Clock in... by gwerbret on Tuesday July 15, 2025 @03:18PM (#44574830)

Pedant here!

> NIST researchers have made the most accurate atomic clock to date — one that can measure time down to the 19th decimal place.

That's precision, not accuracy.

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Re:NIST Ion Clock Sets New Record for Most Accurate Clock in... by _se on Tuesday July 15, 2025 @03:21PM (#44574847)

Nope, it is not.

A single measurement cannot be precise. Precision is a measure of how close multiple measurements are to one another. Accuracy is how close a single measurement is to its true value.

A clock that can measure a point in time to 19 decimal places with respect to its true value is accurate.

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Re:NIST Ion Clock Sets New Record for Most Accurate Clock in... by johnnyballgame on Tuesday July 15, 2025 @05:55PM (#44576222)

What is that true value? And was it accurate?

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Re:NIST Ion Clock Sets New Record for Most Accurate Clock in... by _se on Tuesday July 15, 2025 @06:14PM (#44576412)

Unfortunately, I am not a time lord, so I don't know. But I do know the definitions of these words, and that is what they are. You are free to argue with someone else about the true meaning of time.

A single measurement can _never_ be precise, it is simply not possible.

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Re:NIST Ion Clock Sets New Record for Most Accurate Clock in... by RyJones on Tuesday July 15, 2025 @06:59PM (#44576802)

Tell me you have never shot a rifle for score, without saying you haven't.

You can be accurate, precise, or both.

Said clock may be precise, but not accurate.

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Re:NIST Ion Clock Sets New Record for Most Accurate Clock in... by konstantinua00 on Wednesday July 16, 2025 @11:30AM (#44583390)

there is no true value, so it's not accuracy

it's precision

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