DEC 09, 2018 6:01 PM PST

Measurement of Time, Redefined

WRITTEN BY: Daniel Duan

Once defined by the predictable swing of a finely-tuned pendulum in the classic era, the most precise clock these days--the atomic clocks--rely on the electron transition frequency to keep track of time.

In the past a couple of months, two new atomic clocks smashed the history of timekeeping yet again. Both designs involve the NIST, or National Institute of Standards and Technology, where the first atomic clock was built in 1948. The proof-of-concept device was less accurate than quartz clocks at the time. However, it inspired the construction of the first modern day master clock (which uses the atomic transition of cesium-133 to keep track of time) in 1955 at UK's National Physical Laboratory.

What are atomic clocks so accurate? They take advantage of the highly consistent resonance frequency of atom. Take cesium-133 for example, all of the same atoms oscillate at exact 9,192,631,770 cycles per second, without variation among them. The remarkably consistent frequency cannot influenced by any environmental factors, unlike quartz crystals which changes their oscillating frequency at different temperatures.

In a recent publication in the journal Nature physicists at NIST described an optical atomic clock that traps a thousand ytterbium atoms using grids of laser beams. It matches the natural frequency with such a small possible error that it would take almost 14 billion years (our universe has existed for less than that) to lose a second. The ytterbium atomic clock set three new world records in "systematic uncertainty, stability, and reproducibility".

In an article published in the journal Science scientists from Joint Institute for Laboratory Astrophysics (JILA), cohosted by NIST, reported another new design: they turned strontium atoms into quantum gas and packed them into a tiny three-dimensional cube at 1,000 times the density of the previous generation of atomic clocks (which are called one-dimensional clock in comparison).

In older atomic clocks each atom existed as a separate quantum particle with their own energy state. JILA's device created a so-called “quantum many-body system,” which arranges the atoms in the way that the collective exists as a whole in the lowest overall energy state. Compared to the group’s previous 1-D clocks, the new 3-D clock can reach the same level of precision more than 20 times faster. Their data show the 3-D clock achieved a precision of just 3.5 parts error in 10 quintillions (10E-19) in about 2 hours, fastest among all atomic clocks.

The science behind time-keeping has come a long way, with the new atomic clock design bringing the accuracy, precision, and stability of time measurement up to whole new levels. Besides tracking time, scientists also hope that one day these highly advanced clocks can help us explore ripples in the spacetime fabrics, or even hunt for the elusive dark matter.

Source: Seeker/ZMEScience

About the Author
  • Graduated with a bachelor degree in Pharmaceutical Science and a master degree in neuropharmacology, Daniel is a radiopharmaceutical and radiobiology expert based in Ottawa, Canada. With years of experience in biomedical R&D, Daniel is very into writing. He is constantly fascinated by what's happening in the world of science. He hopes to capture the public's interest and promote scientific literacy with his trending news articles. The recurring topics in his Chemistry & Physics trending news section include alternative energy, material science, theoretical physics, medical imaging, and green chemistry.
You May Also Like
AUG 10, 2021
Neuroscience
Is consciousness a quantum phenomenon?
AUG 10, 2021
Is consciousness a quantum phenomenon?
Researchers experiments with quantum fractals reveal promising direction for consciousness research
AUG 18, 2021
Space & Astronomy
The Size of Black Holes Depends on their Feeding Patterns
AUG 18, 2021
The Size of Black Holes Depends on their Feeding Patterns
The feeding patterns of black holes are directly correlated to their size. The corresponding study was published in  ...
AUG 27, 2021
Space & Astronomy
Researchers Model the Titan Moon in a Tube
AUG 27, 2021
Researchers Model the Titan Moon in a Tube
An image of Saturn's moon Titan on November 11, 1980 during Voyager 1's flyby. Courtesy NASA/JPL-CalTech/Kevin M. Gill
SEP 16, 2021
Space & Astronomy
Under Pressure: Physicists Discover New Property of Black Holes and Quantum Gravity
SEP 16, 2021
Under Pressure: Physicists Discover New Property of Black Holes and Quantum Gravity
Two physicists at the University of Sussex have made a startling discovery about black holes: they exert a pressure on t ...
SEP 30, 2021
Microbiology
Malaria Parasite Seems to be Evolving to Evade Diagnostic Tests
SEP 30, 2021
Malaria Parasite Seems to be Evolving to Evade Diagnostic Tests
When health officials are trying to control a disease outbreak, diagnostic tests can be a crucial tool that provides inf ...
OCT 21, 2021
Earth & The Environment
Cosmic Radiation Events shed light on Norse Settlement in the Americas
OCT 21, 2021
Cosmic Radiation Events shed light on Norse Settlement in the Americas
A new open access study published in Nature yesterday showcases a relatively new method in archaeology. In an attempt to ...
Loading Comments...