The current definition of 1 second depends upon the accuracy of the Cesium133 atomic clock. An atomic clock uses the atomic resonance frequency (depends on the time it takes for an electron to jump from excited state to ground state in the outer layers of the atom) as its counter. Since this frequency is a function of the fundamental properties of the atom, it is extremely accurate (small fluctuations can and do exist, due to quantum fluctuations). The Cesium clock is accurate upto 1 part in 1015, and currently defines the second. However, this atomic clock is hard to stabilize, and this has imposed an inherent upper limit to the accuracy.
Vacuum Chamber to cool atoms using a laser (Courtesy: PhysicsWeb)
Now researchers in Japan have demonstrated a way to trap neutral atoms that could herald a new era in timekeeping. The team believes that an optical clock based on Strontium atoms trapped in an optical lattice could lead to clocks that are accurate to one part in 1018, and thus a 1000 fold better than the Cesium clocks:):).
The Japanese team first trapped a cloud of 10,000 Strontium atoms at a temperature of just 2 microkelvin in a one-dimensional optical lattice (a very narrow wire). A blue laser cools down the atoms to that temperature. When a light is shined upon the atoms, the atoms get trapped in the crests and troughs of the light wave! So by measuring the number of atoms in a fixed length of wire, the scientists can find the frequency of the light used, and thus set a new standard for the measurement of time:):).
Vacuum Chamber to cool atoms using a laser (Courtesy: PhysicsWeb)
Now researchers in Japan have demonstrated a way to trap neutral atoms that could herald a new era in timekeeping. The team believes that an optical clock based on Strontium atoms trapped in an optical lattice could lead to clocks that are accurate to one part in 1018, and thus a 1000 fold better than the Cesium clocks:):).
The Japanese team first trapped a cloud of 10,000 Strontium atoms at a temperature of just 2 microkelvin in a one-dimensional optical lattice (a very narrow wire). A blue laser cools down the atoms to that temperature. When a light is shined upon the atoms, the atoms get trapped in the crests and troughs of the light wave! So by measuring the number of atoms in a fixed length of wire, the scientists can find the frequency of the light used, and thus set a new standard for the measurement of time:):).
Improved Optical Clock
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16 Comments:
But I also wonder why? I mean, why does the difference between 10^15 to 10^18 matter? And what is it's practical application (coz we surely don't need that kind of accuracy in our normal lives).
:( looks like i have lots of catchin up to do:( in the next 2 months:)
keep up the good work
Btw
http://o3.indiatimes.com/o3support do u think u will be interested in writing for them?
That is why you dont have one in you basement!
It is needed to do experiments with short-duration time periods.
It will improve accuracy of GPSes which use time from atomic clocks for sychronisation calculations.
Moreover, there's the thrill factor in making the best in the business.
@Gindy: Its almost the same time every time. It does vary, but within a verry narrow range. All the hard work goes into reducing that range. However, nature prevents us from attaining infinite accuracy due to something called the Heisenberg's uncertainty principle. (In this case, time-energy uncertainty)
@sray: Any particular reason for Strontium?
Noticed it recently that u have a comment counter, and that I'm on top in it.
Wow! Analyzing chemical reactions! Thats interesting! Never ever thought that they could be used for that!
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