In the solar system, the position of the Earth is undoubtedly quite wonderful: in terms of volume, the Earth is the largest of the rocky planets in the entire solar system, but compared to the gaseous planets, the Earth is undoubtedly insignificant - whether it is Jupiter or Saturn, or two kings, it is several times the volume of the Earth.
It may be a coincidence that humans live on the largest rocky planet in the solar system, but it is indeed good luck. Because if Mars or Mercury are in the position of the Earth and can also give birth to human beings, then human beings will undoubtedly be more miserable - because Mars and Mercury are much smaller than the Earth, and if they have a population size like the Earth, I am afraid that resources will be more strained, because the conflicts and wars caused by resources will be more frequent and intense.
So, what would happen to humans assuming that the Earth and the Sun were about the same size?
1. Unrealistic fantasies
In fact, according to the theory of astrophysics, the larger the volume of a celestial body, the greater its gravity, and the greater the limit on the size of living things. A classic example of this is escape velocity. In Phobos, because Phobos is very small, if you have good physical fitness, you may be able to get out of the gravitational confinement of Phobos with a high jump and enter a state of weightlessness (just like the phenomenon of losing gravity in the movie "Mythology"). And because Mars is much larger than the moon, human beings have not dared to consider a manned landing on Mars so far, because if they land on Mars and want astronauts to return to Earth, the escape speed alone will be more difficult to overcome than the moon.
So it is conceivable that if the Earth were the same size as the Sun (let's assume that there is a rocky planet of this size), its gravity and escape speed would be unimaginable, and similarly, the height and movement of human beings would be severely affected by the limitations of gravity.
So from a serious scientific point of view, what would happen to humans if the Earth was as large as the Sun. Because of such a huge celestial body, even if there are living things, at most they are microorganisms.
2. Hypothetical Earth
However, if we assume that these objective laws aside, and that the Earth is indeed as large as the Sun, and that humans are not affected by gravity, what will happen to human history?
If the volume of the Sun were applied to the Earth, at least the Earth's surface area would be more than 10,000 times that of today. This means that the distribution of land and sea on the planet and the territory of countries will expand more than 10,000 times. Even a territorial power like China and the United States has a territory nearly 200 times the size of the current earth - that is, even China and the United States have a surface area equivalent to 200 earths, and as for the volume of Russia and the volume of the African continent, it is even more daring.
Assuming that human beings were born on such a planet, it is estimated that human beings will still be in a primitive state of society today.
Because if human beings are on such a huge planet, then human beings will never be able to leave the African continent and will always be confined to Africa. The rest of the continent is also in a state where wild animals grow wild and thrive in their own territories.
And even if human beings can gradually occupy the continents of Europe, Asia and Africa through the reproduction of infinite time and space, then the American continent and the Australian continent will always be isolated from the sea - because the distance of the Bering Sea ice bridge will also be expanded by 10,000 times. For primitive people, it is also very unrealistic to fantasize about such a large distance. As for the later round-the-world trips, it was also unrealistic.
So, if the earth were the size of the sun, it would be a tragedy rather than a comedy for mankind.