In 1957, mankind’s first artificial satellite was successfully launched, which opened a new chapter for mankind to explore the universe. After we walked out of the earth, we finally saw the true face of the earth. At the same time, we also saw many other planets. Through observation, we found that whether it is stars, planets or other small planets, they can float smoothly in the universe. fall down.
So a friend raised this question: why planets can float in the universe, and will they fall? I believe that many people have also seen a lot of discussions on this issue on the Internet, and some people have given a more scientific explanation, but this explanation is often obscure and difficult. After many people have read it, it is still in the cloud. Today we will use simple and popular language to make a simple description. I believe that friends will understand it immediately after reading it.
Before understanding why planets in the universe can float in the starry sky, let’s take a look at some examples in daily life. I believe that my friends have washing machines in their homes. If you observe the washing process of the washing machine closely, you will find that the washing machine is inside. After the roller is turned, the clothes will run outwards and can float at the same time. As long as a certain speed is maintained, the clothes will always float and will not fall.
I believe that my friends have seen many such examples in reality. When rotating around a center at a high speed, as long as the speed is maintained, the object can always float in the air without falling. In fact, these phenomena in reality have many similarities with the floating of planets in the universe.
I believe that many friends like to throw stones when they are young. When we throw a small stone into the distance, it will fall to the ground. Friends who have studied physics know that this is because the gravity of the earth exerts a direction on the stone. The force under it made it have to turn its head back to the ground.
If we want to keep the stone in the air for a longer time, then we must use more force to throw it higher and farther, so that the stone has a faster speed. Just imagine, if the force we throw is big enough, the stone can get a faster flight speed, then is it possible that it will never land? This is true in theory.
The great physicist Newton also thought about this. He conceived a powerful cannon. As long as the power of the cannon is large enough and the speed of the cannonball is fast enough, then the cannonball can always make a circular motion around the earth. Fall to the ground. And such a conceptual cannon is called Newton’s cannon.
Based on his own thinking and research, Newton calculated the speed at which the projectile would not touch the ground, which is about 7.9 kilometers per second, which is the first cosmic speed we know. Newton calculated such a speed, but due to the technological conditions at the time, it was naturally impossible for an object to reach such a speed, so at that time the object was moving in a circle around the earth, which was only theoretically established.
Later, scientists continued to research and explore based on the first cosmic velocity calculated by Newton, and finally sent the first man-made satellite into space in 1957, moving in a circular motion around the earth. The artificial satellite uses its powerful propulsion force to make it reach a speed of 7.9 kilometers per second, thereby breaking away from the earth’s gravitational restraint, and moving around the earth at a speed of 3.07 kilometers per second in the earth’s orbit.
As long as the artificial satellite has enough power and its speed continues to drop, it will never fall to the ground. Of course, as long as its speed drops, it will also be pulled back to the ground again by the gravity of the earth. When a human spacecraft wants to return to the earth, it uses reverse thrust to first reduce the speed of the spacecraft, and then the gravity of the earth can be achieved. Pull back to the ground.
Artificial satellites move around the earth at a certain speed and can float above the earth’s orbit. In the same way, the moon is 384,000 kilometers away from the earth, and it can float in space because it moves around the earth at a speed of 1.023 kilometers. If the revolution speed of the moon drops, the moon will also fall to the earth under the gravity of the earth.
Let’s look at the eight planets in the solar system. They can float in space because they revolve around the sun at a certain speed. The mass of the stellar sun accounts for 99.86% of the total mass of the entire solar system. The powerful mass brings a strong gravitational pull and pulls the eight planets to fall towards it. If the planets do not want to fall to the sun, they need to move around the sun at a high speed. movement.
Depending on the distance, the planet’s revolution speed is different. The closer you are to the sun, the faster the revolution speed. The average revolution speed of the earth is 29.78 kilometers per second, while the average revolution speed of Mercury reaches 47.87 kilometers per second. This is the reason why planets can float in the universe.
After talking about planets, let’s take a look at why stars can float in the universe. In fact, from the perspective of the solar system, stars are stationary, but from the perspective of the Milky Way, stars are also moving at high speeds. The core around them is In the center of the Milky Way, there is a black hole with a huge mass source.
The center of the Milky Way galaxy is a huge source of gravitation. If the stars of the entire galaxy do not fall into the center of the galaxy, they must move around it at high speed. The same principle is that the closer the star is to the center of the galaxy, the faster its revolution speed. The revolution speed of the sun around the galactic center is about 220 kilometers per second, which is much higher than the revolution speed of the earth around the sun.
So is the entire galaxy still stationary? Of course not. Standing outside the Milky Way, the entire galaxy is a whole, and it also floats in the universe. To maintain this floating state, a high-speed rotation is also required. If it does not rotate, it will be pulled over by another huge source of gravity.
In fact, through observations by scientists, the Milky Way and nearby galaxies are affected by the gravity of the center of the local supercluster, while the Milky Way and the local supercluster are rushing toward a huge space in the universe at a speed of 600 kilometers per second. The center of gravity, this mysterious center of gravity is called the giant source of gravity, and it may be the true center of the universe.
Through these understandings, we can see that an object rotating at a certain speed in reality can float in the air, and its principle is very similar to that of celestial bodies floating in the universe. From this, we can conclude that as long as an object has a certain speed, it can float freely regardless of the influence of gravity, and this principle may provide a certain way for humans to study anti-gravity spacecraft.
Perhaps the mystery of the vast universe is not as mysterious and complicated as we think, it may be hidden in our daily life. This is also the charm of science. The greatness of science is to discover the mystery behind it through some phenomena in nature and some phenomena in people’s daily life, and finally uncover the mysteries of the universe.