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35 sats \ 2 replies \ @south_korea_ln 14 Jan \ on: Why scientists say we need to send clocks to the moon — soon science
On the lunar surface, a single Earth day would be roughly 56 microseconds shorter than on our home planet — a tiny number that can lead to significant inconsistencies over time.

[...]

“The very cheap oscillators may be off by milliseconds or even 10s of milliseconds,” he added. “And that is important because for navigation purposes — we need to have the clocks synchronized to 10s of nanoseconds.”

Even on Earth, GPS navigation systems need to account for these relativistic effects when communicating with the satellites.

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69 sats \ 0 replies \ @south_korea_ln 14 Jan

where

  • : mass and radius of Earth
  • : mass and radius of the Moon
  • G: gravitational constant
  • : speed of light
  • : proper time interval far from the massive body
  • : time interval closer to the massive body
from math import sqrt

G = 6.674e-11
c = 3e8 

M_E = 5.972e24
r_E = 6_371e3

M_M = 7.342e22
r_M = 1_737e3

factor_E = sqrt(1 - (2 * G * M_E) / (r_E * c**2))
factor_M = sqrt(1 - (2 * G * M_M) / (r_M * c**2))

time_dilation_ratio = factor_M / factor_E

day_in_seconds = 24 * 60 * 60
time_difference = (1 - time_dilation_ratio) * day_in_seconds

print(time_dilation_ratio, time_difference)

This gives 57 microseconds.

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0 sats \ 0 replies \ @NovaRift OP 14 Jan

True. Tiny differences will cause major problems in navigation and communication. Maybe they could set up atomic clocks on the Moon or sync them with Earth somehow to keep everything accurate?

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