[Workaccount2]

>The actual port for the actual clock, the little metal thingy that is going buzz, buzz, buzz with voltage every second on the dot? Yeah, that little port isn't actually hooked up to anything, as again, it's so sensitive (impedance matching). So they use the other ports on the card for actual data transfer to the rest of the world.

Can you restate this part in full technical jargon along with more detail? I'm having a hard time following it

[pas]

it sounds like there's some kind of coupling, inductive or optoelectronic

but yes, I also want the juicy details!

so this is the clock

https://en.wikipedia.org/wiki/NIST-F1

or this

https://en.wikipedia.org/wiki/NIST-F2

or there's already F4 too, but it doesn't have a Wikipedia article yet

https://www.nist.gov/news-events/news/2025/04/new-atomic-fou...

but maybe they are talking about the new non-microwave clocks that use Ytterbium-based optical combs ...

or about the Aluminum ion clock

https://www.nist.gov/news-events/news/2025/07/nist-ion-clock...

mind blown

[lisper]

These claims are bullshit. You can get technical details about the clock first-hand at this link:

https://www.nist.gov/pml/time-and-frequency-division/time-re...

and you can see a photo of the actual installation here:

https://www.denver7.com/news/front-range/boulder/new-atomic-...

As you can see, the room is clearly not filled with asbestos. Furthermore, the claim is absurd on its face. Asbestos was banned in the U.S. in March 2024 [1] and the clock was commissioned in May 2025.

The rest of the claims are equally questionable. For example:

> The actual port for the actual clock ... isn't actually hooked up to anything ... they use the other ports on the card for actual data transfer

It's hard to make heads or tails of this, but if you read the technical description of the clock you will see that by the time you get to anything in the system that could reasonably be described as a "card" with "ports" you are so far from the business end of the clock that nothing you do could plausibly have an impact on its operation.

> You can't put anything in the room or take anything out. That's how sensitive the clock is.

This claim is also easily debunked using the formula for gravitational time dilation [2]. The accuracy of the clock is ~10^-16. Calculating the mass of an object 1m away from the clock that would produce this effect is left as an exercise, but it's a lot more than the mass of a human. To get a rough idea, the relativistic time dilation on the surface of the earth is <100 μs/day [3]. That is huge by atomic clock standards, but that is the result of 10^24kg of mass. A human is 20 orders of magnitude lighter.

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[1] https://www.mesotheliomahope.com/legal/legislation/asbestos-...

[2] https://en.wikipedia.org/wiki/Gravitational_time_dilation

[3] https://tf.nist.gov/general/pdf/3278.pdf

[zamadatix]

Agreed the stated claims don't seem to make much sense. Using a point mass 1 meter away and (G*M)/(r*c^2) I'm getting that you'd have to stand next to the clock for ~61 years to cause a time dilation due to gravity exceeding 10^-16 seconds.

[lisper]

Actually, it's even worse than that: the design of the clock makes it so that the cesium atoms doing the actual time keeping are in free-fall while they are being observed. So it is physically impossible for any gravitational influence to change the accuracy of the clock.