The atomic clock from JILA can deviate by only one second after 30 billion years, thanks to its extreme precision.
Scientists at the JILA research institute in the United States have developed a new type of optical atomic clock that is so precise it can measure the smallest effects predicted by Einstein’s general theory of relativity. This clock could help define a second more accurately, leading to the discovery of new mineral deposits underground, as reported by Interesting Engineering on July 2.
Optical lattice used to measure light reflected from atoms. (Photo: K. Palubicki/NIST)
Traditional atomic clocks use microwaves to define the length of a second. However, research shows that shining visible light on atoms can help count seconds more accurately due to the higher frequency of light waves. The optical atomic clock can deviate by one second after 30 billion years compared to microwaves. To achieve this level of accuracy, the clock must measure an extremely small fraction of a second.
Instead of using a beam of visible light, the JILA research team employs a light network called an optical lattice to measure tens of thousands of atoms simultaneously. This method provides the atomic clock with more data to measure a second accurately. While the optical lattice method has been used before, the JILA researchers conducted measurements in a relatively novel way, helping to reduce two sources of error: the laser measuring the atoms and the impact of atoms colliding when they are tightly compressed.
According to Einstein’s general theory of relativity, gravitational force affects time. A strong gravitational field slows the flow of time. The clock developed by JILA is sensitive enough to measure the effects of gravity on timekeeping at the millimeter scale.
Quantum computers rely on the characteristics of atoms and molecules to perform complex calculations. Since the JILA clock can measure accurately, the research team plans to use it in the micro realm, where general relativity intersects with quantum mechanics, to measure changes in the flow of time due to gravitational influences. Meanwhile, the clock’s accuracy could assist scientists in timing over vast distances in space. “If we want to land a spacecraft on Mars accurately, we need a clock that is many times more precise than GPS systems,” said Jun Ye, a physicist at JILA.
JILA is a joint institute between the National Institute of Standards and Technology (NIST) and the University of Colorado Boulder. The research team will publish their findings in the journal Physical Review Letters.
