People in the real world rarely die of natural aging, mostly because of diseases or accidents. Especially in ancient times, due to famine, war and disease, the average life expectancy was very low. Now, because the people are relatively well-off and do not lack food, there has been no major war for a long time. In addition, with the rapid development of modern medical technology in recent decades, the number of elderly people with long life is increasing.
Scientists' research shows that the ultimate life span of human beings is about 120 years old and will not exceed 150 years old. The causes of human aging and death are cell aging and death. The human body is made up of thousands of cells, which can replicate and renew themselves through division. But the number of cell divisions is limited. Because every time a cell divides, the telomeres at the end of the DNA chain shorten. Human cells can only divide 50 times at most, which fundamentally limits the ultimate life span of human beings. The division cycle of human cells is usually 2.4 years, so the ultimate life span of human beings is about 120 years.
The internal organs of the human body may have problems due to disease or aging, and can be replaced, but it cannot fundamentally solve the problem. People's memory and consciousness occur in the brain, and various physiological activities are also controlled by the brain. Death defined by modern medicine is brain death, so brain aging death is the biggest problem. Modern medical technology cannot make human beings live forever. It is impossible to exceed the physiological limit of life. However, society and technology have been progressing, and it may soon be possible to greatly improve human life span by modifying human genes. However, if human beings can't transfer their thinking consciousness in any way, it may be difficult for human beings to avoid the fate of aging and death. In addition, it is meaningless to simply prolong people's life, and it is more important to avoid people's aging. Because the human body is getting older and older, the thinking and reaction ability of people over 100 is getting worse and worse, so life is obviously boring when they are young.