Science fiction movies often have the following scene: humans lie in the dormant compartment of a spaceship, their eyes closed and open, they are already on another colonized planet. Everyone knows that in order to fantasize into reality, sleep technology is the key, how to make humans wake up after temporarily stopping metabolism, hibernating animals have become the object of research, especially arctic ground squirrels that hibernate for up to 8 months a year, but also let people see the hope of dormant space travel.
Arctic ground squirrel appearance and ordinary squirrel appearance is not much different, mainly living in northern Canada, Alaska, Siberia and other dry and cold areas, due to the particularity of the living environment, they have to forage a large number of food from summer to prepare for winter sleep, but also to store enough seeds and fruits in the cave to replenish physical strength in time after hibernation.
With the drop in temperature, Arctic ground squirrels began to hibernate in August, during hibernation their body temperature will drop to about minus 3 degrees Celsius, the heartbeat is only once a minute, even the temperature of the brain and blood will drop below zero, but it will not be frozen, and by the end of April and the beginning of May of the following year, the Arctic ground squirrels that wake up from hibernation will be reactivated.
As one of the longest hibernating animals in the world, researchers have long been interested in the hibernation behavior of Arctic ground squirrels, first of all, why they "do not freeze", and second, how they maintain the body's metabolism. The researchers found that the body temperature of the bear during hibernation is about 4 degrees Celsius, but the Arctic ground squirrel reaches minus 3 degrees Celsius, in contrast, the latter's body temperature drop is greater, and the energy consumption should also increase, but they use the "nitrogen cycle" like the bear to complete the body's adaptation, which is why they can maintain the body's metabolism.
Simply put, Arctic ground squirrels use urea to maintain physical strength, and they will use the "waste" excreted in the urine - urea during hibernation, recycle free nitrogen into essential amino acids, and then convert it into protein to make up for the energy lost during hibernation. What's more, the metabolic activity of Arctic squirrels is curbed during hibernation, and the collagen that was originally decomposed with metabolism is stored, which not only maintains energy, but also avoids severe muscle degeneration.
Therefore, the way Arctic ground squirrels hibernate seems to provide many references for humans, such as how to keep muscles from atrophy for long-term bedridden people; for example, for space travel, how to freeze, sleep does not affect human metabolism and so on.
In fact, people have long tried to find the key and password for human space travel from the body of hibernating animals, as early as 1968, the former Soviet Union sent russian tortoises that hibernated for 9 months a year into space, and the two tortoises returned to Earth unharmed after completing 7 days of space travel, except for weight loss.
In terms of species alone, the Arctic ground squirrel is more referenced to humans than the Russian tortoise, although the Arctic ground squirrel has not yet been in space like the Russian tortoise, but with the rapid changes in science and technology, and the pace of human travel to other planets accelerates, if humans will eventually complete the ultra-long-distance flight in a dormant way, the Arctic ground squirrel is likely to become a test product, instead of humans to test metabolic adaptation.
In fact, in addition to sending hibernating animals to space to observe changes in their bodily functions, many people have always been fascinated by human sleep, the most common being the "cryonics technology" that began in the 1960s. The so-called "cryonics", is the use of cryopreservation of the human body, and look forward to the future to achieve resurrection, it is said that there have been nearly 150 people and nearly 80 animals in the post-mortem completed freezing, these frozen people need to pay a single time to the cryonics agency 5 to 120,000 US dollars, you can be indefinitely placed in liquid nitrogen frozen, the difference in the preservation of the part led to the difference in price, mainly divided into the head and the whole body, but no matter which part of the body is preserved, those frozen on the one hand hope for the development of science and technology, By pressing the "pause button" on the dead body and waiting for regeneration, on the other hand, it is believed that freezing can repair the body. However, so far, the technology has still wandered between science and fantasy, and there has been no practical progress and breakthrough.
So, whether it's learning and mimicking animal hibernation, or space travel through cryonics, it's still some way from being realized. The effects of the microgravity environment on the brain, heart, muscles, bones, vision and other human organs are still unknown, if humans can really grasp and use the adaptation and regulation of the body during animal hibernation, it will not only open a new way of life, then it may be the time to sleep for space travel and travel the universe.