Before the 16th century, the ancients mistakenly thought that the center of the universe was a stationary earth, the shape of the earth was a sphere, and the planets except the earth were constantly orbiting the earth, and the moon and the sun were the same, which is the so-called "geocentric theory".
In 1543, the Polish astronomer Copernicus formally proposed a complete "heliocentric cosmic model" through the "Theory of Celestial Motion", which probably means that the center of the universe is not the earth, but the sun, the earth is constantly moving, it takes 24 hours to run a week, only the moon is running around the earth, but the sun in the center of the universe is stationary, and the other planets are in circular motion around the sun.
Of course, everyone now knows that neither the earth nor the sun is the center of the universe, and like us humans, there are times when lifespan ends.
More than fifty years ago, American astronauts have landed on the moon 6 times, but also shared with us the lunar soil, many years later, China's own space station is under construction, the probe retrieved from the moon soil also has new research findings, the second country that successfully landed a rover on Mars, is us!
Humans have never called the earth, how do scientists determine that the mass is about 5.965 × 10 kg?
In fact, as early as 1798, the British physicist and chemist Henry Cavendish calculated the mass of the Earth at about 60 trillion tons through the "torsion scale". The law of gravitation should have been heard of, right?
Cavendish calculates the density of the Earth through its constants to derive the constant G. The earth's internal structure is significantly layered, so the density is not the same, but through many experiments, Cavendish calculated an average density value, equivalent to 5.481 times the density of water.
Of course, these two values are in error with the results calculated in the 21st century, but they are not much different. The great scientist never married, and finally died in England, and you may not expect that he was still doing scientific experiments the night before his death, and later generations gave him the title of "the first man to call the earth". At present, the scientific community recognizes that the mass of the Earth is about 5.965 × 10 kg, including the sun that we have not been to, or even never, can never land manned, and the mass of other moons, planets and stars, is also estimated by the same method, and the gravitational coefficient G has become more and more accurate, which has laid an important foundation for the rapid development of aerospace technology.
The mass of the Earth is estimated, so is this value decreasing or increasing? American scientists have given the answer
There are always people who wonder, human beings on the earth so big, there are trees cut down, there are animal hunting, many countries the birth rate is also declining, not to mention the use of fresh water resources on the earth is also less and less, will not these lead to changes in the quality of the earth?
Yes, it is true that the mass of the Earth changes from year to year, but all of the above is insignificant compared to the total mass of the Earth. However, recently, American scientists have published a new study related to the earth's mass. Guillaume Gronov, a scientist who specializes in atmospheric escape, said that atmospheric escape is making the total mass of the Earth smaller and smaller, but this is a problem that the planets cannot avoid.
Atmospheric escape loses up to 75,000 metric tons of mass per year, how long can the Earth's atmosphere last?
Judging from the satellite analysis data, the mass lost by the earth due to atmospheric escape every year is 75,000 metric tons, and the metric tons here are actually the same as the tons we say, but the unit name is different.
But while we don't feel it, Earth is always hit by asteroids, a process that helps The Planet gain mass by an average of 15,000 metric tons per year. That is to say, if the increased mass of the asteroid hitting the Earth is offset by the mass of the atmospheric escape loss, the mass lost by the Earth is about 60,000 metric tons per year.
Moreover, although atmospheric escape loses some of its mass, plants on Earth can use photosynthesis to replenish some mass into the atmosphere, such as volcanic eruptions.
To be more specific, if the Earth's mass were to decrease by 600 million tons a year, then in about 5 billion years, the Earth's atmosphere would completely disappear. However, after adding the mass of the atmosphere replenishment, it will not be possible to exhaust it until 15.4 trillion years later.
Yes, with scientists' current knowledge of everything in the universe, it is impossible for humans to stand on Earth forever, or even on a planet in the solar system in four or five billion years. The reason is also very simple, the sun is currently like a young adult, it is the most stable period of its life, but in billions of years, the sun may swallow the earth, even if this scene does not occur, the earth at that time is no longer within the habitable range.
Therefore, for many years, many scientists at home and abroad have been looking for other planets in the solar system and the wider universe besides The Earth. Although billions of years may seem like a long time ago, there have been many mass extinction events in the past billion years on Earth, and no one can be sure when the next one will come, so it is of course better for humans to have more places to live.