Neil deGrasse Tyson Explains the REAL Length of Day
StarTalk・2 minutes read
Earth's rotation lasts 23 hours, 56 minutes, and 4 seconds, causing variations in solar day length. Leap seconds are added to maintain a consistent 24-hour day to account for Earth's orbit and tidal influences.
Insights
- Earth's rotation takes 23 hours, 56 minutes, and 4 seconds, not a full 24 hours, impacting our daily lives structured around the solar day.
- Variations in Earth's rotation, influenced by factors like tides and mass distribution changes, necessitate the addition of leap seconds to maintain a consistent 24-hour day, showcasing the meticulous management of time and the scientific complexities involved.
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Recent questions
How long does it take for Earth to rotate on its axis?
Earth takes 23 hours, 56 minutes, and 4 seconds to rotate on its axis, not the commonly known 24 hours.
What causes variations in the length of a solar day throughout the year?
Earth's orbit not being a perfect circle causes variations in the length of a solar day throughout the year.
How do tides on the ocean floor influence Earth's rotation?
Tides on the ocean floor, influenced by the moon, slow down Earth's rotation.
How are leap seconds added to maintain a consistent 24-hour day?
Leap seconds are added internationally when Earth's rotation falls behind, occurring on June 30th or December 31st.
How can mass distribution affect Earth's rotation speed?
Skaters' movements illustrate how changing mass distribution can alter rotation speed.
Related videos
Summary
00:00
"Earth's Rotation: Timekeeping Complexity Unveiled"
- Earth takes 23 hours, 56 minutes, and 4 seconds to rotate on its axis, not the commonly known 24 hours.
- This duration is known as a sidereal day, based on the stars' positions, but our daily lives are structured around the solar day, which accounts for Earth's orbit around the sun.
- Earth's orbit is not a perfect circle, causing variations in the length of a solar day throughout the year.
- Tides on the ocean floor, influenced by the moon, slow down Earth's rotation, leading to the moon moving away from us by a few inches annually.
- To maintain a consistent 24-hour day, leap seconds are added internationally when Earth's rotation falls behind, occurring on June 30th or December 31st.
- The rotation of Earth can be affected by factors like tidal sloshing, animal migrations, earthquakes, and melting land glaciers.
- Skaters' movements illustrate how changing mass distribution can alter rotation speed, similar to how Earth's rotation can be affected by continental shifts or volcanic activity.
- Despite theoretical ideas like using jet engines to alter Earth's rotation, the planet's immense mass renders such attempts ineffective.
- The meticulous management of time, including the introduction of leap seconds, ensures the accuracy of our clocks and schedules.
- The complexities of Earth's rotation highlight the intricate scientific considerations that underpin our everyday timekeeping systems.
16:07
"Countdown to Leap Second Celebration"
- Mention of preparing for the next leap second
- Suggestion of a special show to celebrate a leap second with an atomic clock
- Reminder to have champagne for the celebration
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