What the world's most accurate clock can tell us about Earth and the cosmos

Image courtesy of Dr. Ed Marti. This January 25, 2017 image shows a strontium optical clock stored in Jun Ye's laboratory at the University of Colorado, Boulder.
For the clock at Jun Ye's basement laboratory at the University of Colorado, to lose one secondabout the time it has been existing, it would take 15 million years.

The Chinese-American scientist and Hidetoshi Katori from Japan will share $3 million in the 2022 Breakthrough Prize for Fundamental Physics.

They developed separate techniques that used lasers to cool and trap atoms. Then they harnessed their vibrations to drive "optical latticeclocks," which are the most accurate timekeeping devices ever made.

Comparatively, the current atomic clocks only lose one second every 100 million years.

What is the benefit of greater accuracy?

Ye said to AFP that it was an instrument that would allow him to explore the fundamental fabric of space-time and the universe.

Researchers in Ye's laboratory have demonstrated that time moves slower if the clock is moved closer than the ground by a matterof centimeters. This is consistent with Einstein's prediction of relativity.

These clocks can be applied to current technology and could improve GPS navigation accuracy up to a thousand times, or help land a unmanned spaceplane safely on Mars.

This handout photo, taken September 8, 2021, shows Jun Ye, a Chinese-American scientist who invented a super-accurate timer.

A brief history of time

Since ancient Egyptians and Chinese created sundials, the goal has been to improve timekeeping precision and accuracy.

The invention of the pendulum clock, in 1656, was a major breakthrough. It relies on a swingingweight to keep time. A few decades later, chronometers were precise enough to determine the ship's longitude at sea.

Quartz clocks were introduced in the early 20th century. They are jolted with electricity at specific frequencies and produce a very precise number of ticks per second.

Modern electronics include many quartz clocks, but they are still susceptible to variations due to manufacturing processes or environmental conditions such as temperature.

The next big leap in timekeeping was achieved by harnessing the movement of energized electrons to create atomic clocks that are immune to environmental variations.

Physics experts know that electrons, which orbit the nucleus a particular type of atom, will jump to a higher frequency, causing them to orbit farther away from the nucleus.

Image courtesy of Dr. Ed Marti. This January 25, 2017 image shows a strontium optical clock stored in Jun Ye's laboratory at the University of Colorado, Boulder.

Atomic clocks produce the frequency at which atoms of the element Cesium jump to higher energy states.

A detector then counts the number of energized atoms and adjusts the frequency to make the clock more precise.

This precision is so great that, since 1967, one second has been defined to be 9,192,631,770 oscillations a Cesium-atom.

Exploring the universe and Earth

Katori's and Ye’s laboratories have discovered ways to improve atomicclocks by moving oscillations towards the visible end the electromagnetic spectrum. This allows them to be more precise.

They needed a way of capturing the atoms, in this case the element strontium.

Gravitation or other forces can cause atoms to fall, and this could lead to a loss in accuracy. Relativity would also affect timekeeping.

The inventors invented an "optical Lattice" that uses laser waves to create a stationary egg-shaped shape.

Ye is very excited about the possibilities of using his clock. By synchronizing the clocks at the best observatories around the globe down to the very last fraction of a second, astronomers could better understand black holes.

A better clock can shed light on Earth's geological processes with new technology.

Relativity says that time slows down as it nears a large body. Therefore, a clock with sufficient accuracy could be used to tell scientists the difference between volcanic lava and solid rock below the surface. This would help predict an eruption.

You can also measure the levels of oceans or the amount of water flowing beneath deserts.

Ye believes that the next challenge will be to reduce the size of the technology so that it can be transported from a laboratory.

Scientist admits that it can sometimes be difficult to explain basic physics concepts to the general public.

He said that clocks are a tangible object that people can connect to when they hear them.

2021 AFP