Time dilation, as predicted by Einstein's theory of relativity, is the phenomenon where time runs differently for observers in different gravitational fields or relative speeds. While time dilation has been observed and measured in various experiments, it does not significantly affect the biological growth of the human body in everyday circumstances. There are a few reasons for this:
Relative Speeds: The effects of time dilation due to relative speeds, as experienced in everyday life, are negligible. The speeds at which humans typically move are vastly slower than the speeds required to observe noticeable time dilation. For example, the time dilation experienced by astronauts on the International Space Station orbiting the Earth at a high speed is only a fraction of a second compared to a person on the surface.
Gravitational Time Dilation: Gravitational time dilation occurs in the presence of strong gravitational fields, where time runs slower near massive objects. However, the gravitational fields experienced by humans on Earth are not strong enough to cause significant time dilation effects on biological growth. The differences in gravitational fields between different heights on Earth are minuscule compared to extreme scenarios near black holes, for example.
Timescales and Biological Processes: The timescales at which biological processes occur in the human body, such as cell division, metabolism, and growth, are much faster than the time dilation effects observed in everyday situations. The biological processes in our bodies are governed by chemical and biological interactions that occur on a microscopic level, and the timescales involved are not in the range where time dilation becomes noticeable.
While time dilation is a real and observed phenomenon, its effects on biological growth are negligible within the normal range of human experiences. It is only in extreme scenarios involving very high speeds or strong gravitational fields, such as those encountered in astrophysical contexts, that time dilation becomes significant and observable.