The weightlessness in the space laboratory is caused by the acceleration that the astronauts rotate around the earth and point out of the earth. This acceleration field basically "smoothes out" the curvature gradient of the Earth's spatio-temporal topology. At this time, the astronauts are in weightlessness and there is no gravity. In fact, it is in a state of "vector force balance".
The space-time topological curvature gradient field of astronauts in outer space spacecraft is established by galaxies; For example, in the solar system, on the one hand, the gradient of the space-time topological curvature gradient field mainly established by the sun is so flat that the solar gravity caused by the sun is very small; On the other hand, the "circumferential acceleration" field of spacecraft motion will also "smooth" the space-time topological curvature gradient field of the sun. Of course, if the spacecraft has acceleration in other directions, astronauts will feel a "back thrust" caused by acceleration. Astronauts' flight in outer space will be mainly controlled by the "push-back state", unless the spacecraft moves at a constant speed and there is no "Ren Woxing" that emits flames or jets. If you encounter a "gravitational slingshot", the "push-back state" is more obvious.
To solve the problem of "weightlessness" in future space navigation, we can only rely on electrostatic force or build a rotating acceleration field in the spacecraft.
Astronauts leave the earth and go into space, where they have been in weightlessness.
The weight from the body when sitting down and the weight from the arm when raising your hand constantly remind people of the difference between up and down. If you enter a state of weightlessness, all this will disappear. This will cause physical discomfort, especially when people arrive in space for the first time, and they can't help but start to doubt themselves. Is this really interesting? Vomiting will make you feel bored, and 1 day in space will make you depressed. When people are under the gravity of the earth, the liquid in your body will flow down. When you are in space, the liquid will flow back. It's like you stood upside down on the earth for three hours.
Gravity determines the size of human heart and the layout of cardiovascular system. The whole human body, whether it is the skeleton frame or muscle strength, is shaped by the gravity of the earth. People on the earth are always in a state of ease, even if they are used to holding their heads high. Even people who are used to holding their heads up and holding their chests high have to bear gravity. If gravity disappears, people's muscles and bones will weaken day by day.
In the space capsule, astronauts need to practice a lot of lifting fitness equipment, including binding their bodies with elastic materials to simulate gravity, but even with the most advanced sports equipment, the bone density of astronauts' hips and femur has dropped by 8% so far. Even when they returned to Earth, their bones began to degenerate. So how big is the impact of weightlessness on human Ad Astra research? Whether long-term weightlessness is a serious degradation of the body, and whether we have become disabled after returning to the earth, we are still studying, but we still can't answer.
Astronauts no longer accelerate when they enter space. Are astronauts weightless in this state of free travel?
1 in order to get rid of the gravity of the earth, scientists calculated the first cosmic speed of rocket launch, and the second cosmic speed was used to run to the moon and go to Mars.
After the rocket sent the astronauts into space, it has been spinning around the earth at the launch speed. People also fly with the inertia of launch inside and outside the cabin, and float in the cabin due to weightlessness.
Astronauts roam in space, and their weightless bodies are like free-floating balloons, so astronauts will feel uncomfortable when they suddenly enter weightlessness.
Astronauts fly with the cabin. Once people leave the cabin, they still fly with the cabin. As you can see, the first time they left the cabin, they were all tied with belts. This is a spacewalk in weightlessness.
If people want to return to the earth, the cabin should resist the high temperature of 1000 degrees caused by atmospheric friction, and there is a heat-resistant layer in the cabin to ensure the normal temperature.
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