The Physics of aging

Up until today, I have thought that aging was more of a biological process. However, after reading the argument made in this article, I have been convinced that we may have been thinking about aging in the wrong way. In this new perspective of viewing the process of aging, there is no longer the innate senescence or aging as a biological necessity. Instead, aging is viewed as a "wearing out" process, aging due to accumulated effects of recurrent stress.

This recurrent stress is due to thermal motion in our cells. The water molecules constantly colliding with the structures inside our cells provide thermal energy for the protein machines to function. However, the constant chaos may be what wears down the cells themselves.

To combat the previous view, Sir Peter Medawar, a Nobel-Prize winning biologist, explains that a natural biological clock would be unecessary. It is hard to explain how natural selection could have selected for senescence. He provides data using test tubes showing that even if people did not age and everyone could die at any age, there would still be less old people due to probability of dying by random chance. The risk of death in  human doubles every seven years after the age of 30.

Thermal damage is not the only source of damage in our cells. Some regular processes may produce radicals, highly reactive atoms that can damage DNA. The probability of free radical production constitutes to a background of risk of cell damage.

I encourage you to read the article as well.

Source:

http://nautil.us/issue/36/aging/physics-makes-aging-inevitable-not-biology