Dec 2, 2024 01:54 AM
https://eos.org/articles/the-relatively-...nar-clocks
INTRO: Using Einstein's theory of general relativity, physicists found that clocks on the moon would run 56 microseconds faster than clocks on Earth. That finding will help future lunar missions navigate.
What time is it on the Moon?
In April 2024, the White House issued a challenge to scientists to establish a lunar time standard, looking ahead to increased international presence on the Moon and potential human bases as part of NASA's Artemis initiative. The real question being puzzled over isn't "What time is it?" but, rather, "How quickly does time pass?"
What time a clock reads can be set by any timekeeper, but physics determines how quickly time passes. In the early years of the 20th century, Albert Einstein determined that two observers won't agree on how long an hour is if they aren't moving at the same speed in the same direction. That disagreement also holds between a person on Earth's surface and another in orbit or on the Moon.
"If we are on the Moon, clocks are going to tick differently [than on Earth]," said theoretical physicist Bijunath Patla of the National Institute of Standards and Technology (NIST) in Boulder, Colo. He noted that the Moon's motion relative to ours makes clocks run slower than Earth standard, but its lower gravity leads to clocks running faster. "So these are two competing effects, and the net result of this is a 56-microseconds-per-day drift." (That's 0.000056 second.)
Patla and his NIST physicist colleague Neil Ashby used Einstein’s theory of general relativity to calculate this number, an improvement over previous analyses. They published their results in the Astronomical Journal..... (MORE - details)
INTRO: Using Einstein's theory of general relativity, physicists found that clocks on the moon would run 56 microseconds faster than clocks on Earth. That finding will help future lunar missions navigate.
What time is it on the Moon?
In April 2024, the White House issued a challenge to scientists to establish a lunar time standard, looking ahead to increased international presence on the Moon and potential human bases as part of NASA's Artemis initiative. The real question being puzzled over isn't "What time is it?" but, rather, "How quickly does time pass?"
What time a clock reads can be set by any timekeeper, but physics determines how quickly time passes. In the early years of the 20th century, Albert Einstein determined that two observers won't agree on how long an hour is if they aren't moving at the same speed in the same direction. That disagreement also holds between a person on Earth's surface and another in orbit or on the Moon.
"If we are on the Moon, clocks are going to tick differently [than on Earth]," said theoretical physicist Bijunath Patla of the National Institute of Standards and Technology (NIST) in Boulder, Colo. He noted that the Moon's motion relative to ours makes clocks run slower than Earth standard, but its lower gravity leads to clocks running faster. "So these are two competing effects, and the net result of this is a 56-microseconds-per-day drift." (That's 0.000056 second.)
Patla and his NIST physicist colleague Neil Ashby used Einstein’s theory of general relativity to calculate this number, an improvement over previous analyses. They published their results in the Astronomical Journal..... (MORE - details)