Today Will Be One Of The Shortest Days On Record And Scientists Don't Know Why

As of August 5, 2025, Earth will experience one of the shortest days on record—by just over a millisecond. This unexpected increase in rotational speed has puzzled scientists and may force changes in how we keep time in the future.

Key Facts:

On August 5, 2025, Earth’s solar day will be 1.25 milliseconds shorter than the standard 24 hours.
Similar shortened days occurred on July 9 and July 22, 2025.
The shortest recorded day was July 5, 2024, at 1.66 milliseconds under 24 hours.
Earth’s rotation had previously been slowing down since official records began in 1973.
Scientists suspect the liquid core and tidal effects from the moon play a role, but the recent acceleration is still unexplained.

The Rest of The Story:

While most won’t notice a millisecond difference, precision timekeepers and scientists are watching Earth’s rotation closely. On certain days in 2025—July 9, July 22, and August 5—the solar day will fall just short of the usual 86,400 seconds.

Solar days are based on the sun’s position, measured from noon to noon. In contrast, a sidereal day—one complete 360-degree rotation relative to the stars—lasts about 23 hours, 56 minutes, and 4.1 seconds.

Earth’s solar day has typically grown longer over time, primarily due to the moon’s gravitational effects, which cause the planet’s rotation to slow.

However, that trend appears to have reversed. Recent years show Earth is speeding up.

While temporary changes can be tied to the moon’s position relative to Earth’s equator—affecting tidal forces—longer-term causes remain elusive.

Some experts have floated global warming as a factor, but a leading theory points to the slowing of Earth’s liquid core.

This could shift mass within the planet and make the outer layers rotate faster.

If the pace continues, timekeepers may eventually need to subtract a “negative leap second” for the first time—essentially deleting one second from the global time standard.

Commentary:

This latest development should serve as a reminder that claims of settled science are often premature. For decades, scientists believed Earth’s rotation was gradually slowing due to the moon’s gravitational drag.

That understanding, backed by decades of data, is now being challenged.

It’s a humbling moment. Even with all our advanced satellite tracking, atomic clocks, and physics models, we’re still struggling to explain why our planet is suddenly moving just a bit faster.

The forces driving Earth’s rotation involve deep, hidden dynamics like liquid metal moving thousands of miles beneath our feet—an area we understand only in theory.

This should encourage some caution in how we approach climate models and timekeeping adjustments. While environmental shifts like global warming are easy targets for blame, there’s no firm evidence yet connecting it to Earth’s rotational speed.

As one possibility among many, it’s far from a definitive answer.

Timekeeping agencies like the International Earth Rotation and Reference Systems Service (IERS) are tasked with maintaining global time standards.

The fact they may need to subtract time—something never done before—highlights how fluid our measurements truly are.

What’s more, these subtle shifts in Earth’s spin have real-world implications.

From satellite navigation systems to internet servers, even slight inaccuracies can compound if the base measurement of time starts to wobble.

In a world increasingly obsessed with precision—from financial trades to quantum computing—this should be a wake-up call.

Nature doesn’t always follow our charts and graphs. The Earth turns at its own pace, not ours.

And when the very foundation of time starts shifting—literally—it’s worth pausing to consider how little we truly control.

The Bottom Line:

Earth is spinning slightly faster than it used to, and scientists don’t know why. This could lead to the first-ever deletion of a second from official timekeeping.

It’s a subtle reminder that even our most basic assumptions about nature are still open to revision.