The International Bureau of Weights and Measurements (BIPM) has announced the discontinuation of leap seconds, a timekeeping adjustment that has been used since 1972 to align atomic time with Earth's rotation. The decision, effective May 2027, eliminates the need for adding or subtracting seconds to Coordinated Universal Time (UTC) to maintain synchronization with astronomical time (UT1). Leap seconds were introduced to address the growing discrepancy between atomic clocks and Earth's rotational speed, which slows due to tidal friction from the moon and Earth's rotation. The BIPM's move comes after concerns about the potential need for a negative leap second, which could have caused significant technological disruptions. A 2024 Nature study indicated that melting ice from climate change might have necessitated a negative leap second as early as 2029. Tech companies like Google and Meta have previously used 'smear' methods to handle leap seconds by spreading the adjustment over a day. However, the BIPM determined that the risks of negative leap seconds, which had never been tested, outweighed the benefits of maintaining alignment. BIPM time department director Patrizia Tavella noted that the decision was influenced by industry tests showing failures with negative leap seconds. The organization will implement the change on May 20, 2027, coinciding with the anniversary of the Metre Convention and Metrology Day. While the discontinuation of leap seconds simplifies timekeeping for technology reliant on UTC, the BIPM acknowledged that atomic and astronomical time will continue to drift apart, leading to the eventual need for a leap hour, though this is expected to occur millennia in the future. Tavella emphasized that systems relying on UTC will not need to make adjustments, while those using UT1 will need to account for the growing difference between the two time standards. The decision marks the end of a decades-long debate in the timekeeping community and aims to prevent future technological issues caused by time adjustments.

Scientists in Vienna have achieved a major breakthrough in timekeeping by creating the world’s first self-stabilizing nuclear clock, a technology that could eventually surpass even the most precise atomic clocks. Instead of relying on electrons in atoms, the clock uses the tiny nuclei of thorium atoms, which are far less sensitive to outside disturbances.

京都大学、情報通信機構（NICT）、ネオアーク株式会社、東京都立大学との共同研究による論文“Nitrogen-Pressure Dependence of Coherent Population Trapping Signal Characteristics in Microfabricated Rubidium Vapor Cells”が、IEEE Open Journal of Ultrasonics, Ferroelectrics, and Frequency Control (OJ-UFFC) に採択されました。 本研究では、チップスケール原子時計（Chip-Scale Atomic Clock: CSAC）の主要構成要素であるMEMSルビジウムガスセルを対象に、セル内部の窒素（N₂）バッファガス圧力がCoherent Population Trapping（CPT）信号特性に与える影響を系統的に調べました。その結果、MEMSガスセルでは単純にバッファガス圧力を高くしてCPT線幅を狭めればよいわけではなく、線幅とCPT信号振幅の両方を考慮したバッファガス設計が重要であることを示しています。本成果は、ウェハレベルで量産可能なMEMS蒸気セルのバッファガス設計および、小型・高安定な原子時計の実現に向けた設計指針につながるものです。 本研究成果は、総務省「令和4年度から新たに実施する電波資源拡大のための研究開発（課題番号：JPJ000254）」における委託研究「周波数資源の有効活用に向けた高精度時刻同期基盤の研究開発」により実施した成果の一部です。関係各位に深く感謝いたします。 【論文情報】Shun Kiyose, Masahiro Fukuoka, Yusuke Odagiri, Satoshi Hatano, Shigeyoshi Goka, Motoaki Hara, Yoshikazu HiraiNitrogen-Pressure Dependence of Coherent Population Trapping Signal Characteristics in Microfabricated Rubidium Vapor Cells…

While the global scientific community is considering the idea of revising the exact length of the second, the Quantum Technologies Center in Singapore has unveiled yet another contender for the title of the planet’s chief timekeeper. Tests of the latest lutetium atomic clock have shown that its oscillation rate not only meets existing standards but […] Post It doesn’t get any more accurate than this: A new atomic clock is aiming for a world record at Root-Nation.com.

Singapore's Centre for Quantum Technologies (CQT) has announced a breakthrough in atomic clock technology with the development of a lutetium-ion atomic clock that achieves unprecedented accuracy. According to research published in Nature on September 23, 2026, the clock would be off by no more than one second over 300 billion years, representing the highest accuracy reported for an optical atomic clock to date. The CQT team measured the frequency of their lutetium clock to 19 decimal places, reporting an uncertainty of 1 x 10^-19, the lowest for any optical atomic clock. They also built two identical clocks and compared their ticking over 200 hours, finding they agreed to an uncertainty of 5.7 x 10^-19, the most precise clock comparison ever recorded. The lutetium clock's exceptional stability comes from its minimal sensitivity to temperature and magnetic fields, allowing it to maintain accuracy across extreme environmental conditions from Death Valley to the Antarctic plateau. This stability could support studies of gravity and fundamental physics, while contributing data toward a possible redefinition of the second after 2030. The team, led by Associate Professor Murray Barrett, has worked with lutetium for over a decade, making them the only group currently using this element for timekeeping. The researchers plan to miniaturize the lab-scale clock into a transportable system, which could enable broader applications in fields such as geodesy and gravitational monitoring. The development represents a significant advancement in timekeeping technology, potentially paving the way for new standards in measuring time and fundamental physical constants.

Singapore's Centre for Quantum Technologies (CQT) has announced a breakthrough in atomic clock technology with the development of a lutetium-ion atomic clock that achieves unprecedented accuracy. According to research published in Nature on September 23, 2026, the clock would be off by no more than one second over 300 billion years, representing the highest accuracy reported for an optical atomic clock to date. The CQT team measured the frequency of their lutetium clock to 19 decimal places, reporting an uncertainty of 1 x 10^-19, the lowest for any optical atomic clock. They also built two identical clocks and compared their ticking over 200 hours, finding they agreed to an uncertainty of 5.7 x 10^-19, the most precise clock comparison ever recorded. The lutetium clock's exceptional stability comes from its minimal sensitivity to temperature and magnetic fields, allowing it to maintain accuracy across extreme environmental conditions from Death Valley to the Antarctic plateau. This stability could support studies of gravity and fundamental physics, while contributing data toward a possible redefinition of the second after 2030. The team, led by Associate Professor Murray Barrett, has worked with lutetium for over a decade, making them the only group currently using this element for timekeeping. The researchers plan to miniaturize the lab-scale clock into a transportable system, which could enable broader applications in fields such as geodesy and gravitational monitoring. The development represents a significant advancement in timekeeping technology, potentially paving the way for new standards in measuring time and fundamental physical constants.

Researchers in Japan have mapped how thorium-229 nuclei behave inside a crystal, helping clear a path toward a new generation of ultra-utlra-ultraprecise timekeepers.

Microchip has launched a new miniature atomic clock designed for use in the space industry, which features enhanced radiation resistance and an extended operating temperature range. This device is designed to maintain exceptionally accurate timekeeping on small spacecraft, particularly CubeSats and satellites operating in low Earth orbit (LEO), during periods when there is no access […] Post Microchip’s Space Breakthrough: Ultra-Stable Atomic Clock for Satellites Unveiled at Root-Nation.com.

This new result contributes to the international effort to define the second with a much greater level of accuracy than before, enabling new scientific and technological advances