In one day, the earth rotates once on its own axis. But what would happen if the earth suddenly started spinning faster? There are theories about this.
Stuttgart – It turns and turns without us noticing it. The earth rotates once around its own axis in 23 hours and a good 56 minutes. But what if the whole thing suddenly happened faster? What would that mean for our planet and ultimately for us humans?
Farewell to satellite television: if the earth rotates faster, satellites are thrown out of their orbit
First of all: It is not very likely that such a scenario will occur in the near future. And if it does, humanity will no longer exist by then. In order to be able to empathize with the whole thing, one must first know how fast the earth is moving. That depends on where on Earth you are, because the blue planet rotates fastest around your waist. Because the earth rotates on its axis, its circumference is greatest at the equator.
An example makes it clearer: A point on the equator has to travel much further in 24 hours to return to its starting position than, say, the city of Chicago. To make up for the extra distance, the equator spins at about 1,000 miles per hour, while Chicago moves at a more leisurely pace of about 750 miles per hour.
So what happens if we speed things up? The science site popsci.com interviewed scientists about this. The result: If the Earth’s rotation were accelerated by just one mile per hour (1.6 kilometers per hour), the sea level at the equator would rise by a few centimeters as water moves there from the poles. “It might be a couple of years before we realize that,” Witold Fraczek, an analyst at ESRI, a company that makes geographic information system (GIS) software, told the site.
It would be easier to see the acceleration from the satellites in space. Satellites positioned in geosynchronous orbit orbit our planet at a speed equal to the Earth’s rotation, allowing them to remain positioned over the same point at all times. If the Earth rotates a mile an hour faster, the satellites are no longer in the correct position. The possible consequences: satellite communications, television broadcasts and military and secret service operations could be temporarily interrupted. That could also pose a problem for Mercedes-Benz: the Stuttgart carmaker wants to control autonomous cars using satellites.
Some satellites carry fuel and may adjust their position and speed accordingly, but not all do. All other satellites would therefore be useless.
A faster rotation of the earth makes our days shorter
One could still cope with disabled satellites. However, the situation would become far more catastrophic the faster the Earth spins. Because the centrifugal force of the earth’s rotation is constantly trying to throw everything and everyone off the planet. However, gravity is stronger at the moment and we are staying on the ground. If the earth were spinning faster than it is now, the centrifugal force would also increase. With devastating consequences: If the equator were to accelerate to 17,641 miles per hour (about 28,390 kilometers per hour), the centrifugal force would eventually be so great that one would essentially be weightless. Another danger is much more realistic: debris from a Chinese rocket threatens to fall on earth.
A faster rotation of the earth would also have an impact on our time. Because the faster the earth rotates, the shorter our days would become. A one mile per hour increase in speed would shorten the day by only about a minute and a half. With an increase of 100 miles per hour (about 161 kilometers per hour) it would look different: A day would then only have 22 hours. The changed length of day would probably not only mess up our time rhythm, but also that of plants and animals.
We could only feel this acceleration if it happened suddenly and within a very short time. If this process took place over millions of years, humans, plants and animals could adapt to the new conditions. If the Earth’s rotation were to slowly accelerate, it would sweep the atmosphere along. As a result, we wouldn’t necessarily notice a huge difference in daily winds and weather patterns. However, the weather could be more extreme in terms of storms. “Hurricanes will rotate faster and they will contain more energy,” says Sten Odenwald, an astronomer at NASA.
Reverse rain: a faster Earth rotation would turn our world upside down
The additional speed at the equator would also have an effect on our oceans. The water in the oceans would accumulate at the equator. At a speed of 100 miles per hour (about 161 kilometers per hour), the equator would begin to drown. “I think the Amazon Basin, northern Australia and not to mention the islands in the equatorial region would all go under,” says Witold Fraczek. “I don’t know exactly how deep underwater, but I’m guessing about 30 to 65 feet (9 to 20 meters).”
If we double the speed at the equator so that the Earth spins 1,000 miles (about 1,609 kilometers per hour) faster, “that would clearly be a disaster,” says Fraczek. Centrifugal force would pull water hundreds of feet toward the waist of the earth. “Apart from the highest mountains, like Kilimanjaro or the highest peaks of the Andes, everything in the equatorial region would be covered with water. This extra water would be drawn from the polar regions where centrifugal force is less, leaving the Arctic Ocean much shallower.”
At about 17,000 miles per hour (about 27,359 kilometers per hour), the centrifugal force at the equator would equal gravity. There could be reverse rain after that, Fraczek speculates. “Water droplets could move up in the atmosphere.” By then, the Earth would be spinning more than 17 times faster than it is now, and there probably wouldn’t be many people in the equatorial region left to marvel at the phenomenon. Before his death, Stephen Hawking theorized that the universe has an end point.
“To spin faster, it would have to be hit by just the right object”
At about 24,000 miles per hour (38,624 kilometers per hour) – and for thousands of years – the earth’s crust would eventually shift too, flattening at the poles and bulging at the equator. With devastating consequences: “We would experience enormous earthquakes,” says the scientist.
But after all these scenarios, Witold Fraczek can calm down. Since the moon’s formation, the Earth’s rotation has slowed by about 3.8 miles per hour (about 6 kilometers per hour) every 10 million years, largely due to the moon’s gravitational pull on our planet. It is therefore much more likely that the earth’s rotation will continue to slow down in the future instead of accelerating. “It is inconceivable that the earth could rotate so dramatically,” says Odenwald. “To spin faster, it would have to be hit by exactly the right object, and that would liquefy the crust, so we’d be dead anyway.” Another scenario even predicts when life on Earth will no longer be possible : Researchers have calculated when we will run out of air.
