Tag

Atomic Clocks

All articles tagged with #atomic clocks

science7 days ago•3 min saved

Earth’s days drift longer as the planet slows under lunar pull

Earth’s day is gradually lengthening—about 1.7 milliseconds per century—primarily due to tidal braking by the Moon, which is gradually moving away from Earth (~3.8 cm/year). Additional tiny effects come from shifts in Earth’s interior, winds, and ocean currents, including climate-driven glacier melt that redistributes mass. Scientists track these minute changes with atomic clocks and techniques like VLBI. A full stop would take tens of billions of years, well beyond the Sun’s red-giant era.

via BBC Sky at Night Magazine|

#atomic-clocks #climate-change #earth-rotation

science1 month ago•11 min saved

World-Flight Clocks Prove Tiny Time Dilation, Einstein-Style

The 1971 Hafele–Keating experiment flew four cesium atomic clocks around the world and compared them with stationary clocks, finding results that matched Einstein’s relativity: eastbound clocks lagged about 60 nanoseconds and westbound clocks gained about 270 nanoseconds (with tight error bars), due to a combination of high speed and reduced gravity. This tiny, measurable effect scales with speed and altitude and is too small to enable real-world time travel, but it underpins how GPS timing is corrected and confirms the same relativistic effects observed in satellites, spaceflight, and even astronauts’ aging. Overall, time dilation is real and measurable, yet it remains a nanosecond-scale forward-only drift in everyday contexts.

via Space Daily|

#atomic-clocks #gps-relativity #hafele-keating-experiment

science3 months ago•11 min saved

Relativity at GPS scale: why satellites are clocked slow on the ground

GPS satellites carry atomic clocks that are deliberately set to run slow on the ground so that relativistic effects in orbit bring them to the correct rate; special relativity would slow moving clocks by about 7 microseconds per day, while general relativity would speed them up by about 45 microseconds per day, for a net gain of roughly 38 microseconds per day that would cause ~10 km of positional error daily if uncorrected. The main correction is a ground-based frequency offset (about 10.22999999543 MHz instead of 10.23 MHz) so the clock is right in orbit, with smaller orbital variations corrected by the receiver.

via Space Daily|

#atomic-clocks #gps #navigation

science3 months ago•13 min saved

Gravity Makes Time Local: Atomic Clocks Detect Millimeter-Scale Time Differences

The most precise optical atomic clocks can now detect gravitational time dilation over a mere millimeter in a lab: clocks at the bottom run slightly slower than those at the top, enabling direct tests of general relativity at human scales. With precision around one part in 10^21—roughly one second in 30 billion years—this landmark achievement opens practical avenues for gravimetry, geophysics, and possibly redefining the second, signaling that time is locally shaped by gravity rather than universally uniform.

via Space Daily|

#atomic-clocks #general-relativity #gravitational-time-dilation

science3 months ago•12 min saved

Quantum Clocks Probe If Time Itself Can Be in Superposition

Physicists propose using ultra-precise atomic clocks and trapped ions to test whether time can behave as a quantum object, potentially existing in multiple states at once. By cooling ions, controlling quantum states, and exploring squeezed vacuum states, the work aims to reveal quantum signatures of time and explore how relativity and quantum mechanics describe the flow of time.

via SciTechDaily|

#atomic-clocks #quantum #relativity

science8 months ago•1 min saved

Power Outages Disrupt Atomic Clocks and Internet Time Services in Colorado

Last week, some of the world's most precise atomic clocks were off by about five-millionths of a second due to a wind-induced power outage, highlighting the sensitivity of high-precision time standards used globally.

via The New York Times|

#atomic-clocks #national-institute-of-standards-and-technology #power-outage

science10 months ago•7 min saved

Quantum Techniques Boost Precision of Optical Atomic Clocks

The article discusses advancements in quantum-amplified global-phase spectroscopy on optical clock transitions, highlighting recent developments in quantum metrology and atomic clock technology, including enhanced stability and precision through quantum entanglement and squeezing techniques.

via Nature|

#atomic-clocks #optical-clock #phase-amplification

science1 year ago•4 min saved

Quantum Clocks and Networks Challenge Foundations of Physics

A new experiment involving entangled atomic clocks could provide crucial insights into how quantum mechanics and general relativity interact, potentially advancing the quest for a unified theory of everything. The proposed experiment uses quantum networks to test the effects of gravity on quantum superpositions, which could reveal how spacetime curvature influences quantum phenomena.

via IFLScience|

#atomic-clocks #entanglement #general-relativity

science1 year ago•3 min saved

Earth's Days Shorten as Rotation Speeds Up in 2025

Earth experienced one of its shortest days on record on July 9, 2025, due to the moon's gravitational effects, with two more such days expected this summer. This phenomenon is linked to the moon's position and gravitational pull, which can temporarily speed up Earth's rotation. Scientists monitor these variations using atomic clocks, and if the trend continues, it could lead to the need for a negative leap second to keep civil time aligned with Earth's rotation.

via Space|

#atomic-clocks #earth #moon-influence

science1 year ago•2 min saved

Earth's Rotation Accelerates, Making July 9, 2025, Possibly the Shortest Day Ever

On July 9, 2025, Earth will experience one of its shortest days since 1960, finishing about 1.3 to 1.6 milliseconds early due to the planet's accelerated rotation, influenced by factors like the Moon's orbit and shifts in Earth's mass distribution. This short-term change is part of a series of days in 2025 with slightly faster spins, prompting scientists to monitor future data for potential negative leap seconds to keep atomic time aligned with Earth's rotation. The phenomenon is scientifically significant but poses no practical risk to daily life, aiding in climate modeling and satellite navigation research.

via Times of India|

#atomic-clocks #earths-spin #negative-leap-second

science-and-technology2 years ago•1 min saved

"Human Activities Accelerating Earth's Spin, Prompting Time Adjustment"

Timekeeping scientists are considering subtracting a leap second from atomic clocks to adjust for the Earth's faster-than-expected rotation due to climate change, marking the first instance of removing a second rather than adding one. The Earth's rotation has been gradually slowing, leading to the addition of 27 leap seconds between 1972 and 2016, but now the melting poles are causing the need for a negative leap-second correction as early as 2026. This adjustment has implications for systems reliant on precise timekeeping, such as GPS satellites and financial transactions, and highlights the complex relationship between atomic timekeeping and our understanding of time.

via HODINKEE|

#atomic-clocks #climate-change #earths-rotation

science-and-technology2 years ago•4 min saved

"Global Warming's Impact on Earth's Rotation and Timekeeping"

Earth's rotation is speeding up, potentially necessitating the subtraction of a second from world clocks around 2029, a phenomenon known as a "negative leap second." This change is attributed to the planet's hot liquid core and rapid melting of ice at the poles. The discrepancy between astronomical and atomic time, which has been managed through leap seconds, poses challenges for computer systems and technology. While some advocate for eliminating leap seconds altogether, others argue for maintaining the current system.

via KABC-TV|

#atomic-clocks #earths-rotation #geophysics

science-and-technology2 years ago•9 min saved

"Melting Polar Ice Slows Earth's Rotation, Prompting Time Adjustment"

Earth's changing spin may necessitate the subtraction of a second from world clocks around 2029 due to the planet rotating faster than before, a situation described as "unprecedented" by scientists. The Earth's slowing rotation, caused by tides, has been counteracted by the melting of ice at the poles, delaying the need for a "negative leap second." This complex issue involves physics, global politics, climate change, and technology, with implications for timekeeping systems and computer operations. While some experts believe a negative leap second is inevitable, others argue that long-term predictions about Earth's rotation are uncertain.

via 4029tv|

#atomic-clocks #earths-rotation #geophysics

physics2 years ago•6 min saved

"Harnessing Quantum Dark States for Superior Noise Reduction"

Physicists have discovered a method to create highly entangled spin-squeezed states in multilevel atoms by harnessing superradiance inside an optical cavity, leading to the generation of dark states that are immune to superradiance and emit light at a much slower pace. This breakthrough could significantly enhance the precision of atomic clocks and quantum metrology, offering opportunities for quantum-enhanced measurements and potential applications in noise reduction.

via Phys.org|

#atomic-clocks #dark-states #noise-reduction

science2 years ago•5 min saved

"Clock Systematic Shift Due to Dipole-Dipole Interactions"

Researchers at JILA and NIST have observed millihertz-level cooperative Lamb shifts in an optical atomic clock, shedding light on the intricate interactions within atomic clocks and their potential impact on clock accuracy. By using a cubic lattice to measure specific energy shifts within an array of strontium-87 atoms, the team demonstrated the influence of dipole-dipole interactions on clock performance and the importance of understanding and controlling these interactions at high density. The study's findings could lead to improved timekeeping precision and further exploration of quantum physics in clock systems.

via Phys.org|

#atomic-clocks #cooperative-lamb-shifts #dipole-dipole-interactions