Why is this? This involves the different effects of space and ground environment on the body.
As we all know, the space environment is completely different from the earth environment. For the earth, it is a place where the environment is relatively vacuum, lack of oxygen, radiation surge and obvious temperature difference, which is very harmful to life. So when building a manned spacecraft, a completely closed space capsule will be designed.
Secondly, there is almost no day and night in space. Because our space capsule runs in the direction of the earth's rotation, it is very fast; Under normal circumstances, a day on the ground is basically 24 hours, but in space, there will be some time changes due to the difference of the flight trajectory of the spacecraft where the astronauts are located.
Generally speaking, if the flight speed is fast, the corresponding frontal alternation time will be faster. When the spacecraft flies at the same speed, the higher the flight orbit, the longer the periodic change of day and night. So in space, there is an illusion of time occasionally.
The most obvious environmental difference we are familiar with may be the gravitational effect that disappears because of the loss of celestial gravity.
Although there is no complete weightlessness in space, it is almost a microgravity environment, which is almost negligible for human beings. Everything is floating in space. Standing, lying and sitting feel basically the same. No special sense of direction. Up, down, left and right can be the foothold.
A drop of water can be fixed directly in the air without any storage tools, just like magic. This age can also correspond to the water content of the human body. Can you imagine a series of processes in which all substances in the environment "float"?
Generally speaking, in space, without the protection of the atmosphere, the radiation existing in various celestial bodies and the universe will spread everywhere without reservation, and many high-energy particles can even pass through some space equipment, which is hard to prevent.
The astronauts on Shenzhou XIII have been on a business trip in space for a month today, but in the new video, some netizens found that not only astronaut Wang Yaping, but also the three members of the space station seem to have put on a little weight. Why is this?
On the earth, the gravity from the center of the earth will make the whole gravity of people fall normally and keep a constant and stable state. The rules are ours on the earth, and we are used to the gravity environment of the earth. Generally speaking, some characteristics of life activities are adjusted according to the environment on the earth.
So under normal circumstances, human blood will circulate normally through the heart, and continuous exercise will also promote the flow of blood. There is gravity in it.
But in the space environment, under the condition of almost complete weightlessness, we can see that some water droplets will float in the air without falling. The human body is more than 70% water, and there is not much circulation ability in this case. In this way, human blood will also change, and its viscosity and flow rate will also change.
Because the circulation of blood and water in the body decreases and gradually accumulates, and because the state of microgravity is scattered all over the body, it is easy to appear "edema", which at first glance looks like gaining weight. The astronauts' own feelings are basically head swelling, or other parts of the body may have a slight swelling feeling, which is the influence of the space environment.
This feeling is like the physical experience of standing upside down for a long time. Living in a space environment for a long time is inevitable.
In space environment, the human body will not only make the body bloated, but also increase the gap between human bones due to weightlessness. Actually, this truth is understandable. When the two substances are superimposed together, the surfaces of the two substances will be closely attached when gravity falls, but when this downward gravity is lost, the gap between the two bones may increase. So some people say that there is a "height growth" effect in space, although these heights are only temporary.
Astronauts live in a space completely different from their understanding of the environment for a long time, and their physical properties will change accordingly. The most direct influence may come from the water circulation in the body, from which many physical effects can also be derived. For example, compression of eyeball and brain, osteoporosis, muscle atrophy, and inevitable high-energy particle flash.
In order to cope with these physical effects, many physical exercise facilities will be set up in the space station. China's space station is equipped with gymnasium equipment, and astronauts have exercise time every day to ensure the normal operation of their bodies and reduce the impact of space environment on their bodies.
In the future, with the development of the space industry, the working system and guarantee for astronauts in space will gradually mature.