



We are on a spinning ball suspended in space even though we don’t ever feel that it is spinning. As I was thinking about Earth and its spin, I began to wonder if it is possible for our planet to ever stop spinning. I know I think about a lot of weird stuff but this is a legitimate question. So I began researching on this topic.

Will the earth ever stop spinning? The good news is it won’t happen anytime in our lifetimes. However, the Earth is definitely slowing down. But at the rate at which the spin is slowing down, it would take billions of years for the earth to stop rotating. The Earth would already be destroyed by various other phenomena, the sun would engulf the planet or we’d destroy it ourselves or some other event.

The slowing Earth would have other effects though.

HOW DOES SPIN OF THE EARTH AFFECT LIFE ON EARTH?

Earth’s rotation plays a significant role for life to prevail on Earth. The formation of day and night are a direct result of the rotation. Plants and few other organisms have metabolisms that are governed by formation of day and night. Weather patterns depend on the rotation as well. The precession of the axis of rotation and changes in axial shift have affected the climate and hence the evolution of organisms. One of the most important things is that the Earth’s core rotates when the Earth rotates. The rotation of the metallic core produces the intense magnetic shield that protects the Earth and its living components from the lethal radiation.

Slowing down of the planet would have adverse effects on life that thrives on the planet.

WHY IS THE EARTH SLOWING DOWN?

Due to slowing of Earth, days will eventually get longer. In past, days were even shorter. Let us take a look at why it slowed down.

While the Earth was still in its infant stage i.e. in young solar system, a large celestial body about the size of mars collided with the Earth and in that enormous collision, the alignment of our planet and its rotation changed. It made our planet spin so fast that days were about 6 hours long. From the debris of the collision, our moon was formed. Due to the gravitational association of the Earth and moon, the planet is slowing down.

When the Earth’s gravity grabbed on to the moon, both the Earth and the moon slowed down to compensate for the loss of momentum in the system. The gravitational association of the Earth and the moon also causes tides on Earth. This slows down the Earth bit by bit due to the friction caused by the sloshing of water. The moon is continuously moving away from the Earth a few centimetres per year to compensate.

Overtime, the days became 24 hours from 6 hours. The tidal forces would eventually slow down Earth significantly but the laws of physics wouldn’t allow the rotation to cease completely. In the last 100 years, the Earth’s rotation slowed by 1.4 milliseconds i.e. the days are 1.4 milliseconds longer now and that is why in 2012, a second was added to the clock to compensate. In about 180 million years, the days will be longer by an hour. But will the earth stop spinning eventually? Well, there’s more chance of other events occurring before that happens.

EFFECTS OF EARTH SLOWING DOWN ON THE PLANET

The slow rotation in the past hundred years or so has coincided with more Earthquakes than usual. The simple notion is that the Earth slows down very slowly due to which it shrinks near the equator. However the tectonic plates do not shrink so easily leading to edges of the plates getting squeezed. Even though the squeezing isn’t huge, it puts stress on the boundaries of the plates that are already under a huge amount of stress. Hence the Earthquakes are more likely in these regions.

Through observations and experimentation, scientists have found a correlation of slowing down of Earth to Earthquakes. A research team of geologists studied every Earthquake to occur since 1900 above 7.0 magnitudes and found that every 32 years, there was a spike in the number of big Earthquakes throughout the world. They found that this spike was caused due to slowing down of Earth. Every 30 years or so, the Earth slowed down and the slowdown happened right before the Earthquakes.

Other than the Earthquakes, life on Earth could adapt to the longer days as the slowing down is happening really slowly. Organisms will have enough time to adapt and evolve to last in an environment with longer days.

OTHER FACTORS THAT AFFECT THE ROTATIONAL PERIOD OF THE EARTH

Events occurring on the Earth can also affect the rotation of Earth. The effect is really minute but worth mentioning. Large scale events such as the Earthquake in the Indian Ocean in 2004 which caused havoc in South-East Asia has shortened the day by 3 microseconds by affecting the planet’s moment of inertia.

Post glacial rebound that is ongoing since the last ice age is affecting the Earth’s rotation by changing the distribution of the Earth’s mass and hence influencing its moment of inertia and by conservation of angular momentum, affecting the rotation period.

Different manmade structures also affect the spin of the Earth. NASA calculated that the water stored in the Three Gorges dam in China has increased the length of the day by 0.06 microseconds.

WHAT WOULD HAPPEN IF THE EARTH EVENTUALLY STOPS SPINNING?

There isn’t any chance that the Earth will stop spinning anytime soon. But it is fun to imagine what would happen if it eventually stops spinning, if fun for you is global catastrophes.

Our planet will have days that have sunlight for half a year and darkness for half a year. It’s pretty obvious that the days will be way hotter and nights will be way colder. Both extremes will be unbearable for human beings to survive.

The wind patterns will change to a north south orientation from now cold equator and now hot poles due to the tilt of the axis. Only non extreme place on the planet will be the mid latitudes with right atmosphere density that can support life.

When the rotation slows down significantly, the oceans will migrate to towards the poles leaving a massive landmass near the equator. The layers of earth will slow down at different rates resulting in massive earthquakes and major volcanic activities before eventually the Earth stops spinning.

When the rotation stops, the core would stop spinning as well. This leads to the disappearance of the magnetic shield protecting the earth from solar radiation. This will be a bad news for any living organism as harmful radiation can now penetrate the atmosphere.

Even if some organisms manage to survive the catastrophes mentioned above, the lack of 24 hour day will kill them as the mechanisms in the body of most organisms depend on a 24 our day.

CONCLUSION

In short, we can say the earth won’t stop spinning anytime soon. It is true that the earth is slowing down but at the rate at which it is slowing down the earth would be destroyed by some other events. The spin of the earth has a huge impact on life on Earth so stopping would lead to worldwide disasters from earthquakes to storms to droughts. So it’s good that we are safe....for now!

Thank you for reading and keep on being curious!