Sending humans anywhere in space beyond the Moon opens up frontiers in the logistics of health, food, and psychology that we don’t yet fully understand. As you may have come across in many science fiction works, a potential solution to this problem is that people are put into a long-term sleep state, that is, a kind of hibernation, during years of space travel; When it comes to the point to be reached, you may have come across that you have been awakened from this sleep.
Unlike faster-than-light travel and wormholes, the possibility of putting astronauts into some kind of hibernation does indeed sound possible. In fact, even the European Space Agency is conducting serious research on whether this is possible. But forcing people into a coma for space travel doesn’t seem like an unlikely option, according to a new study.
The hibernation scenario seems to be just a science fiction element
The results of a new study by three researchers from Chile show the potential for long-term human inactivity. reveals a mathematical barrier to realization. And that impediment means that such a scenario can only apply to works of science fiction, not actually such a thing.
To explore this possibility, Roberto F. Nespolo and Carlos Mejias of the Millennium Institute for Integrative Biology and Francisco Bozinovic of the Pontifical Catholic University of Chile set out to investigate the relationship between body mass and energy expenditure in hibernating animals. During their research, the experts discovered a minimal level of metabolism that allows cells to stay in cold and low-oxygen conditions.
This meant that for relatively heavy animals like us in such a situation, the energy savings we can expect from entering a deep, hibernating-like state would be negligible. So even if we spent our days in space sleeping normally, rather than going into a hibernation-like state, it would have worked out better.
Humans need to have hundreds of kilograms of adipose tissue to hibernate for a long time
The word hibernation usually refers to a bear that has retreated into its lair for months of hibernation. brings. Although bears are dormant during the cold winter months, this dormancy is not much like true hibernation for smaller creatures such as ground squirrels and bats. In these animals, body temperature drops, metabolism decreases, and heart rate and breathing slow down. This process can reduce energy expenditure by up to 98 percent in some cases, eliminating the need to hunt or forage. But even in such a situation, these animals continue to burn fuel reserves for energy and lose more than a quarter of their body weight in the process.
Now imagine applying the same conditions to a human being. In such a case, this would mean that humans would need several hundred kJ of body fat to replace their daily food intake of about 12,000 kJ during the hibernation period. If we apply hibernation to the space travel scenario, that means humans will lose about six grams of fat per day during their sleep state. This figure can reach up to two kilograms in a year.
Losing just two kilograms can be quite acceptable for a short trip within space standards. But if you’ve been dreaming of going on a decades-long interstellar journey in a dormant state as an average adult, we have bad news for you: You’ll need at least a few hundred kilograms of adipose tissue for that to happen.
Hibernation does not result in huge energy savings in large animals
This is a result of how large numbers of hibernating animals we humans or larger It also explains that less. As explained in detail in previous studies on the subject; Performing a statistical analysis among various hibernating species, the researchers concluded that the daily energy expenditure of hibernating animals is fairly balanced. For example, according to this, the energy produced by a gram of tissue taken from a small mammal such as a 25 gram leaf-eared bat is equal to the energy produced by tissue taken from an 820 gram hibernating ground squirrel.
If we were to figure out how to hibernate as efficiently as a dormouse, we might assume that every gram of our tissue would need the same energy as every gram of them. But this situation is completely different when mammals are active. The scaling of the relationship between active metabolism and mass indicates that hibernation does not really save much energy in larger animals. In other words, the total energy need we will need while hibernating will not be much different from what we need during normal resting state.
This also explains the differences in hibernation between bears and other mammals. Also, hibernation on this scale means that people need to cool their bodies down and reduce their heart rate and breathing, all of which are dangerous changes that will have a very bad effect on our metabolism and have not very pleasant consequences. In short, forcing humans into a state of hibernation is not an unlikely solution for long space travels.