Amazing precision

Thread Starter

jpanhalt

Joined Jan 18, 2008
11,087
I have sort of a passing interest in time measurement and wanted to share a portion of an e-mail from the director of the time division at NIST (Dr. Tom O'brian):

You may be interested in some very recent results using two new kinds of atomic clocks,
each with an accuracy better than 1 second in 1 billion years:
http://www.nist.gov/public_affairs/releases/logic_clock/logic_clock.html

Each of the two clocks described -- a clock based on a single ion of
mercury, and a clock using quantum computing principles with an ion
of aluminum -- has an uncertainty of about 2 x 10^-17. That level of
uncertainty is equivalent to the gravitational shift in moving up or
down by about 20 cm (about 8 inches).

That is an order of magnitude better than than before. It used to be you could tell which floor in a building you were on. Now, you can tell how many steps there are.

John
 

Dave

Joined Nov 17, 2003
6,969
I recall reading about this recently John, it is true amazing accuracy.

What caught my eye was the fact they they are moving to non-caesium atoms; the last time looked at his was the NIST-F1 a couple of years back and I recall caesium being the atom of choice back then (at least it was the majority atom).

It will be interesting to see where this goes in future, the precision as a function of time is like an "Inverse" Moore's Law with precision as log-time against the year.

Dave
 

nomurphy

Joined Aug 8, 2005
567
Although the concept of time is easily adopted and wonderfully useful, and very difficult to ignore, it is only an abstraction (like the sqrt -1). It doesn't really exist.

Time only exists in the mind of man (or any other reasonably aware creature or alien out there). Hence, I am really sorry to say, no time-travel but in one's imagination.

Ooops, look at the time, must be going now.
 

bloguetronica

Joined Apr 27, 2007
1,541
The reason for such precision is that there are no mechanical parts affected by factors such as temperature, humidity, etc. The process of nuclear decaying is not affected by conditions like temperature, pressure, etc. The rate of decaying is a inverse exponential with mathematical precision, literally.
 

Thread Starter

jpanhalt

Joined Jan 18, 2008
11,087
That's looks like the same picture as in Wikipedia. In the US, we have WWV to synchronize to atomic time. Does BBC have that service? John
 
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