Interstellar immigration suit

The earth is our only home at present, but it will not be our final habitat, because with the progress of science and technology, human beings can get rid of the gravitational bondage of the earth and enter outer space by spaceship. Now there are some large spacecraft in outer space-space station, which is equivalent to "base". Astronauts can live in these space stations for a long time and fly for months or even six months at a time before returning to Earth. In view of the fact that human beings have been able to carry out manned space flight, some people think that in the future, human beings may leave the earth, go deep into the universe and emigrate to other planets. However, some studies show that human beings may be "trapped" on the earth for a long time, unless there is a revolutionary change in our spacecraft technology. What's going on here? Is the earth really a "cage"?

As we know, the environment of the earth is completely different from that of outer space. For example, on the ground, we can breathe freely and be directly exposed to the atmosphere. We don't need to worry about cosmic radiation hurting us, and we don't need to worry about whether it will be hit by small debris such as meteorites and meteoroids. It's very safe. In outer space, oxygen has become a very precious consumption substance, because there is almost no air in outer space, and it is almost in a vacuum state. If we are directly exposed to a vacuum, our body fluids may boil and our bodies may swell until they explode and die. Therefore, spacecraft flying in outer space need to carry oxygen, and if they need to carry out extravehicular activities, they need to wear specially developed extravehicular spacesuits.

In outer space, the radiation from the universe is also quite strong, which is a fatal threat. Besides, we will be in microgravity or zero gravity in outer space. Because we need to go into space by spaceship, if our spaceship slows down, it will fall directly. In order to prevent the spacecraft from being pulled down by the gravity of the earth, the speed of the spacecraft flying hundreds of kilometers in low earth orbit is close to the first cosmic speed of the earth, 7.9 kilometers per second. At this time, the gravity of the earth and the "centrifugal force" of the spacecraft are in balance, and we are floating in the spacecraft, with almost no gravity. What will happen to the human body in the environment of high radiation and microgravity?

Humans have lived on the earth for millions of years. Our bones and hearts have adapted to the gravity of the earth, and our lungs have adapted to the pressure of the earth's atmosphere. Studies have shown that one of the main reasons why our body cells don't grow up is gravity, because gravity restricts the growth of these cells. The smaller the cell, the smaller the influence of the earth's gravity on the cell, which is almost negligible. However, when these cells are large, some complex cytoskeleton may be needed to support the whole cell, otherwise these large cells may collapse or be destroyed. When we enter a brand-new outer space environment, our bodies will inevitably undergo some changes. For example, we are floating after entering space, and we can't know the up and down direction. This is not the biggest problem. In the case of microgravity, our bodies may suffer some damage.

Although most people have never really been to outer space so far and can't really experience the changes brought by the space environment, they have also experienced overweight and weightlessness when riding a roller coaster. However, the time spent riding the roller coaster is very short, and the physical changes caused by weightlessness can actually be ignored. Those astronauts may fly in outer space for a long time, shorter space flights may last for several days and longer space flights may last for half a year. Astronauts fly in outer space for several months and half a year, and their physical changes can not be ignored. When they are in weightlessness for a long time, the astronauts' bones will loosen. Now some studies show that astronauts' brains have also changed.

In weightlessness, our body fluids cannot naturally flow downward, and the body fluids of various organs and tissues will be redistributed. For example, on the ground, our body fluids will not gather in the brain under the action of gravity, but more body fluids will flow to the brain under weightlessness, and the body fluids in the lower limbs may decrease. For the lower limbs, the problem may not be very big, but for the brain, it may bring some influence.

Scientists observed and studied 12 Russian astronauts by using a technique called fiber tracer imaging. These astronauts have been flying in space for a long time, with an average flight time of 172 days, almost six months. In this study, researchers can see whether the "wiring pattern" in astronauts' brains has changed. In order to confirm whether the brain has changed in weightlessness, scientists measured these astronauts before entering space, after returning to Earth 10 and after returning to Earth for 7 months. At first, the researchers found that the shape of the corpus callosum in the astronauts' brains changed, and later found that the astronauts' ventricles also expanded, and some nerve bundles related to sensory movement, such as cortical pons and cortical spinal cord bundles, also showed microstructure changes.

In addition, the researchers also found that there was an obvious change in the heads of these astronauts who performed space missions for a long time, that is, the position of the brain in the skull moved up. This will happen to astronauts who fly in space for a long time, but not to astronauts who perform short-term space missions. In this case, the researchers believe that in the long-term weightless space environment, the astronauts' brain tops are "crowded" and the gyrus and sulcus are narrowed, which means that the astronauts' brain tops are "squeezed", leaving less space for cerebrospinal fluid to flow. With the obstruction of cerebrospinal fluid flow, the intracranial pressure of astronauts may increase, which will eventually lead to optic nerve swelling and pituitary deformation.

Seeing that the astronauts' bodies have changed after a long space flight, some people may worry that humans will not leave the earth. Because at present, the farthest footprint of human beings can only reach the moon, and it takes a long time to reach a farther planet. For example, it takes nearly half a year to fly to Mars and tens of thousands of years to fly outside the solar system. After flying in space for several months, some changes have taken place in my body. Is it necessary for human beings to be trapped on the earth?

Although it is true that there may be some changes in the astronauts' bodies, these changes are actually to make astronauts better adapt to the outer space environment. When they return to the earth, they will adjust their bodies to the environment on the ground, and eventually they will recover. This is not an irreversible change. And with the progress of science and technology, our spacecraft will fly faster in the future, and there may be gravity, so it may not take so long to fly to Mars. Moreover, in the environment of artificial gravity, the physical changes of astronauts may not be so obvious, and then interstellar migration can still be realized. Therefore, whether human beings can get out of the earth ultimately depends on our level of scientific and technological development.