Earth’s rotation is changing speed?

Yes, Earth's rotation speed does change — but very slightly, and for different reasons.

1️⃣ Long-term trend: Earth is slowing down
 

• Over millions of years, Earth’s rotation has been gradually slowing.
• Reason: Tidal friction from the Moon. The Moon’s gravitational pull creates tides, and the friction of ocean water moving slows Earth's spin.
• Roughly: Earth slows by about 1.7 milliseconds per century.
• 600 million years ago, a day was only about 21 hours long!

2️⃣ Short-term fluctuations: Earth sometimes speeds up too
 

• In recent years, scientists have observed periods where Earth’s rotation actually sped up very slightly.
• For example, in 2020, Earth recorded some of its shortest days ever measured.
• Cause: Complex interactions like:
• Changes in atmospheric pressure
• Melting glaciers
• Movement in Earth's core (inner and outer core dynamics)
• Large earthquakes shifting mass

3️⃣ Recent headlines (last few years)
 

• In 2020, 2021, and 2022, Earth rotated a bit faster than usual — breaking some records for shortest days.
• Scientists are still studying why: some suggest changes deep in Earth’s core might play a role.