China-Science/Nuclear Clock
China-Science/Nuclear Clock
Dateline : Recent/File
Location : China
Duration : 2'18
Beijing, China - Recent (CCTV - No access Chinese mainland)
1. Sign reading "Department of Physics, Tsinghua University"
2. Various of researchers working in laboratory, adjusting optical equipment
3. Laser wavelength data displayed on computer screen
4. Researchers adjusting optical equipment
5. SOUNDBITE (Chinese) Ding Shiqian, associate professor, Department of Physics of Tsinghua University/adjunct researcher, Beijing Academy of Quantum Information Sciences (ending with shot 6):
"A traditional pendulum clock swings about once a second, and we can tell how much time has passed by counting those swings. Our nuclear optical clock instead uses the rhythm of an atomic nucleus as its 'pendulum.' That rhythm is, of course, much faster than that of a wall clock, at about 2 quadrillion cycles per second. It divides time into extremely fine intervals, allowing us to measure time precisely by counting those cycles."
6. Various of experimental data displayed on computer screen
FILE: China - Exact Location and Date Unknown (CCTV - No access Chinese mainland)
7. Researchers working in laboratory
8. Various of laboratory instruments, experimental data displayed on screens
9. Various of researchers adjusting electronic circuit board
Beijing, China - Recent (CCTV - No access Chinese mainland)
10. Various of researchers adjusting optical equipment
11. Various of laboratory instruments, experimental data displayed on screens
12. SOUNDBITE (Chinese) Ding Shiqian, associate professor, Department of Physics of Tsinghua University/adjunct researcher, Beijing Academy of Quantum Information Sciences (partially overlaid with shot 13):
"An atomic nucleus is tens of thousands of times smaller than the surrounding electron cloud, which makes its rhythm more stable. This means the nuclear optical clock we developed could eventually become even more precise. It may also be possible to make such clocks smaller. Once miniaturized, an ultra-precise timekeeping device could be put to practical use instead of remaining merely a laboratory tool."
++SHOTS OVERLAYING SOUNDBITE++
13. Various of researchers adjusting optical equipment
++SHOTS OVERLAYING SOUNDBITE++
14. Various of researchers adjusting optical equipment
Chinese scientists have developed a nuclear optical clock that measures time through energy changes inside atomic nuclei, a breakthrough that could pave the way for more accurate and portable timekeeping in navigation, deep-space exploration and fundamental physics research.
A team from Tsinghua University, working with researchers at several other Chinese institutions, spent nearly five years developing the clock. The findings were published in the journal Nature on Wednesday.
The researchers developed a continuous-wave vacuum-ultraviolet laser operating at 148.4 nanometers and used it to trigger a transition inside nuclei of thorium-229, a radioactive isotope. By locking the laser's frequency to the steady rhythm of that transition, they were able to create a nuclear clock.
Nuclear optical clocks, which use transitions within the atomic nucleus as their reference, are seen as a potential successor to atomic microwave clocks and optical atomic clocks.
"A traditional pendulum clock swings about once a second, and we can tell how much time has passed by counting those swings. Our nuclear optical clock instead uses the rhythm of an atomic nucleus as its 'pendulum.' That rhythm is, of course, much faster than that of a wall clock, at about 2 quadrillion cycles per second. It divides time into extremely fine intervals, allowing us to measure time precisely by counting those cycles," said Ding Shiqian, an associate professor in Tsinghua University's Department of Physics and an adjunct researcher at the Beijing Academy of Quantum Information Sciences.
The most accurate optical atomic clocks currently use electron transitions to keep time. But electrons are sensitive to disturbances from electric and magnetic fields, temperature changes and laser systems, all of which must be tightly controlled. The best-performing optical atomic clocks therefore remain largely confined to laboratories, making miniaturization and wider practical use difficult.
"An atomic nucleus is tens of thousands of times smaller than the surrounding electron cloud, which makes its rhythm more stable. This means the nuclear optical clock we developed could eventually become even more precise. It may also be possible to make such clocks smaller. Once miniaturized, an ultra-precise timekeeping device could be put to practical use instead of remaining merely a laboratory tool," Ding said.
Researchers said nuclear optical clocks could eventually provide more precise positioning and distance measurements for satellites and spacecraft, supporting navigation, deep-space exploration and other areas requiring highly accurate time and frequency standards.
ID : 8502741
Published : 2026-10-09 01:26
Last Modified : 2026-10-09 01:29:40
Source : China Central Television (CCTV)
Restrictions : No access Chinese mainland
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