Physicists Unveil World’s Most Precise Clock

Today, Andrew Ludlow at the National Institute of Standards and Technology in Boulder and a few buddies unveil the two most accurate clocks ever built. They say their new clocks can keep time with an unprecedented precision of one part in 10[to the negative 18th power]

Ludlow and co put this in perspective: “A measurement at the 1018 fractional level is equivalent to specifying the age of the known universe to a precision of less than one second or Earth’s diameter to less than the width of an atom.”

Their clock is a simple beast, at least in principle. The basic idea is that a second can be defined by the frequency of light emitted by an atom when electrons in the ground state jump to another state.

m.technologyreview.com...


You know, I get sick of reading about doom and dirty tricks all the time. Sometimes it's nice to juat kick back and say "Wow, that's pretty cool." I admit I don't completely understand the science behind these things, but perhaps one of you geniuses can grasp the explanation given in the MIT article.

As the article notes, precision time-telling is important in an increasing number of new technologies (they give GPS satellites as one example). Whether these technologies are put to good or nefarious use is, as always, up to us humans.

Cool. I am sure that it will be very useful in many scientific and technological applications.

I know a lot of people that would continue to show up late for work, appointments and dates... even with the most accurate clock ever.

I don't even wear a watch anymore. I consider keeping track of minutes as so unnecessary anymore.

reply to post by silent thunder


then i have to say wow, thats pretty cool...

wonder how long the battery is going to last in it?

Awesome! Thanks for some fun and positive news

Can I find this watch on Ebay as a wristwatch model?

Impressive technology.

Although, time isn't a linear thing in the universe, days should actually last 23h 56 minutes ~, years last 365 1/4 days so whatever the technology we use to calculate time, it's still just a "statistic" relating to when we started counting.

reply to post by silent thunder

As the article notes, precision time-telling is important in an increasing number of new technologies (they give GPS satellites as one example). Whether these technologies are put to good or nefarious use is, as always, up to us humans.

Not only that it helps with those experiments where they think they broke the laws of relativity because their instruments show, "Hey, we went back in time!!!"



(I Guess that's GPS related too though...)

Originally posted by theMediator
Impressive technology.

Although, time isn't a linear thing in the universe, days should actually last 23h 56 minutes ~, years last 365 1/4 days so whatever the technology we use to calculate time, it's still just a "statistic" relating to when we started counting.

This is measuring seconds though, you know... the things that add up to equal the lofty years and days you're calculating.

Originally posted by silent thunder

Today, Andrew Ludlow at the National Institute of Standards and Technology in Boulder and a few buddies unveil the two most accurate clocks ever built. They say their new clocks can keep time with an unprecedented precision of one part in 10[to the negative 18th power]

m.technologyreview.com...

Silent thunder cited the quote the way it was written, but the author is apparently made a typo, and you don't need to be a math whiz to see the mistake.

It's one part in 10 to the positive 18th power, not one part in 10 to the negative 18th power, which doesn't even make any sense.

For example, you can say a cent is a fraction of a dollar which is one part in 10 to the positive 2 power, or the fraction is 10 to the negative 2 power. You don't say a cent is one part in 10 to the negative 2 power which is what the author of that article did, with the time example.

They stated it correctly later in the article:

The result is a clock that loses only one “tick” in 10^18 “tocks”.

That's positive 18th power, which is correct.

So they say it's going to be accurate to within about 1 second over the next 14 billion years?

Fortunately for them,nobody here now will be around in 14 billion years to check and see if they were right or not.

So you may be wondering, what is it good for? The MIT article also suggests applications:

The best clocks today are sensitive to changes of many metres or kilometres. The new clock should be able to discern changes of around 1 cm at the Earth’s surface. That will be for applications such as hydrology, geology and the measurement of ice pack changes in climate change studies.

I recall reading a paper describing the use of clocks to discern altitude-related gravity changes changes on the order of 1-2 meters, so narrowing this resolution down to 1cm is quite a feat.