There is a heated debate online about the true shape of our planet
These graphics surfing the Internet (see video), of course, confused many. Is it really, if we "drain" the water from the oceans, our Earth looks like such an ugly stub? Let's try to figure it out.
The ancient Greeks were the first to talk about the fact that the Earth has the shape of a ball. The scientist Eratosthenes in the third century BC calculated that the radius of the planet should be 6287 kilometers. Surprisingly, he was only 84 km wrong (our cradle was slightly larger)!
However, already in the middle of the 17th century, scientists began to doubt that the Earth has the shape of a regular ball. They were prompted to this idea by an amazing incident that happened to the French astronomer Jean Richet. In 1672, he left Paris for Cayenne, the capital of French Guiana (this is the overseas department of France in the northeastern part of South America). The purpose of the trip is to observe Mars. Richet took with him an astronomical clock with a second pendulum. But miracles began in South America: the most accurate device began to lag behind every day by 2 minutes 28 seconds. To get the right move, Jean had to shorten the pendulum by 3 mm. However, upon returning to Paris, the clock began … to rush!
Scientists were lost in conjectures until the correct solution was proposed by the well-known Englishman Isaac Newton. He mathematically calculated that such errors in the measurement of time could occur only if the Earth is not a sphere, but an ellipsoid flattened at the poles. Later, Newton was right: it turned out that the polar radius of the Earth is 21.3 km shorter than the equatorial one and is 6356.8 km.
But how noticeably does this affect the shape of the Earth? Could our planet look like a huge space potato due to such irregularities?
Let's take the most noticeable points on earth's relief - Mount Everest (8.8 km) and the Mariana Trench (11 km). How will they look against the background of the Earth, devoid of the ocean? Let's calculate: the diameter of our planet is 12 thousand 742 km. Reduce it by 1000 times for clarity - we get a sphere with a diameter of 12.7 km But this is if you go to the "center" of this "Earth"! And its circumference will be much greater - 40 km. On this ball, Everest will look like a large children's "sandbox" 9 meters high. This speck cannot be seen with the naked eye. The same is with the Mariana Trench - it will look like a scratch 11 meters deep.
Promotional video:
What do the astronauts say? The ISS orbits the Earth at an altitude of 400 kilometers. From this low orbit, our planet is not entirely visible - for this you need to fly away. But examining the surface of the body of our "old woman" from a close distance, the astronauts did not notice that she needed a "tightening".
This is one of the first images of the Earth from space, it was taken by the American Apollo lunar mission. No flaws were found on Earth.
The first general shot of the Earth was taken by the Americans during the Apollo lunar mission. But even on it there is no trace of the "apple core" effect. Well, the most striking example is Mars. Indeed, during the work of the Curiosity rover, scientists were convinced that millions of years ago the surface of the Red Planet was covered by the ocean. Then the water disappeared. However, Mars is completely different from a dug potato.
There are no oceans on Mars that would mask surface defects. The photo shows "scratches", but overall the shape is perfectly round.
It turns out that this fake graphics that excited the minds? Also no. The fact is that the Earth's gravitational anomalies are shown there. Gravitational forces in different parts of the planet deviate noticeably from the average value. This happens because the density of the earth's crust is not uniform, and the shape of the earth is not a perfect sphere. The centrifugal force resulting from the rotation of the Earth also interferes in the calculations.
For example, at the equator, everything becomes lighter. That is why they are trying to build spaceports closer to this line. The calculation is simple: the Proton spacecraft weighs about 700 tons. But at the equator, it pulls 4.3 tons less. This means that 4.3 tons of payload more can be put into orbit! Considering that it costs 12 thousand dollars to deliver 1 kilogram of cargo to the ISS, it is easy to calculate that knowledge of various nuances of gravity can bring benefits of 51 million 600 thousand dollars. And that's just from one space launch.
Yaroslav KOROBATOV