Are we trapped on the earth forever? Astronauts have 3 million red blood cells destroyed every second.

With the development of society, our living standards have been greatly improved. However, in the process of social development, there have also been some problems that need our attention. Some problems may exist in themselves, and some problems may be related to our human development, such as climate warming and mass extinction. Compared with before the industrial revolution, the average temperature of the earth has risen by more than 1.

With the rise of the earth's temperature, glaciers in the North and South Poles and some alpine plateaus have also accelerated their melting speed, and then sea level has risen, and some low-lying coastal areas may be submerged. The persistence of climate warming will also lead to climate anomalies or other problems on the earth, such as extreme drought, floods, wildfires, etc., and the habitats of many wild animals have also been destroyed. In view of the fact that the current situation of the earth is not very optimistic, Mr. Hawking has made some predictions. For example, he thinks that with the development of mankind, more and more fossil fuels will be consumed, and the temperature of the earth will get higher and higher. It is predicted that the earth may become uninhabitable like a fireball around 26, and our way out is to emigrate to other planets. However, some studies show that we humans may be trapped in the earth forever and cannot live without it. What's the matter?

As our only home at present, the earth has already adapted to the earth's environment, for example, we have suitable temperature, liquid water, magnetic field protection, atmosphere, gravity and so on. One of the prerequisites for us to immigrate to a planet very similar to the earth's environment is to find such a planet, and the other is to have the ability of interstellar flight.

For the present level of human technology, it may no longer be difficult to find a potential livable planet in the vast universe. In 221, scientists selected 24 "super livable" planets from more than 4, known exoplanets. These "super livable" planets are slightly larger in size, slightly higher in temperature and slightly higher in oxygen content in the atmosphere.

But it may be impossible for us to reach these "super livable" planets for a long time to come. On the one hand, these "super livable" planets are too far away from our earth, more than 1 light years, which means it will take more than 1 years to reach these "super livable" planets by light-speed spacecraft. On the other hand, scientists have found that astronauts will have some physical problems when flying in outer space.

According to the research report published in Nature Medicine, Dr Guy Trudel from the University of Ottawa said that since the first space flight, those astronauts have been reported with space anemia when they returned to Earth, but we don't know why these astronauts have the problem of space anemia. The current research shows that when we humans enter outer space, more red blood cells will be destroyed, and this problem will always exist during the whole space flight.

Because we have already adapted to the environment on the ground, in the microgravity or zero gravity environment in outer space, our bodies need to make some adjustments to adapt to the environment. For example, our body fluids will transfer to the upper body of our bodies under weightlessness, which will cause our blood vessels to reduce 1% of the fluid. Scientists analyzed the damage of red blood cells of 14 astronauts who participated in the six-month space mission, and found that 3 million red blood cells were destroyed every second during the astronauts' six-month stay on the International Space Station. Although we also have red blood cells destroyed on the ground, only 2 million red blood cells are destroyed every second, and these red blood cells will be replaced when they are destroyed. That is to say, on the ground, our human red blood cells are actually in a state of dynamic balance.

During the six-month flight in the International Space Station, the number of red blood cells in astronauts' bodies was destroyed and replaced, which was 54% more than normal. Scientists believe that astronauts' red blood cells need to be replenished in time after being damaged, otherwise there will be the problem of space anemia. After these astronauts returned to Earth for 3-4 months, although the level of red blood cells gradually returned to normal level, the measurement after returning to Earth for one year showed that the damage degree was still 3% higher than usual.

This is not the first study to analyze the physical changes of astronauts. Scientists have carried out many similar studies before, and many studies have shown that astronauts' bodies do undergo some changes during their flight in outer space. For example, Olga Manko of the Russian Academy of Sciences said that nearly one-third of astronauts have changed their visual system after flying in space for more than three months, and this change belongs to space neuromuscular syndrome. The reason why this happens is that in the microgravity and zero gravity environment in space, blood can't naturally flow to the lower limbs under the action of gravity, which leads to a large amount of blood gathering in the astronauts' brains. During the long-term space mission, the intracranial pressure of astronauts' brains will increase, and finally there may be visual changes such as nerve edema, eye shape change and hyperopia, and the brain and cerebrospinal fluid will also swell.

If we humans want to reach those distant exoplanets, we must first step out of the earth and go deep into the universe. Now these studies show that our human bodies will undergo a series of changes in the microgravity and zero gravity environment in outer space. Are we humans going to be "trapped" on the earth forever and unable to get out of it?

Although flying in outer space for a long time does bring some changes to the body, many changes will basically return to normal level after the astronauts return to Earth for a period of time. Moreover, many problems are caused by astronauts in order to adapt to the environment in outer space, that is, in fact, this is the result of adapting to microgravity and zero gravity. When we carry out long-term space missions in the future, our bodies will also make some adjustments to make us better adapt to the space environment.

Moreover, with the progress of science and technology, many technical problems can actually be solved. Although there is no gravity in outer space, in the future, human beings can make aeroplanes with gravity. Living and working in these aeroplanes with gravity may be as comfortable as on the ground, and the problem of weightlessness will be solved.