The concept of shrinking someone to the size of a Planck length is purely hypothetical and currently beyond the realm of our scientific understanding. The Planck length, approximately 1.616 × 10^-35 meters, is believed to be the smallest meaningful unit of length in the universe. It is derived from fundamental physical constants, such as the speed of light, the gravitational constant, and Planck's constant.
If we were to speculate about what would happen if someone were somehow scaled down to the size of a Planck length, it is difficult to say what the implications would be. Our current understanding of physics breaks down at such extremely small scales, and the laws that govern our macroscopic world may not be applicable or meaningful at that level.
At the Planck scale, where quantum gravity effects are expected to become significant, the structure of spacetime itself is thought to be fundamentally different from our familiar notions. It is unclear how physical quantities like length, time, or the speed of light would behave under such extreme conditions.
Therefore, it is not appropriate to make assumptions about the scaling of physical constants or the behavior of space and time when considering scenarios that involve the Planck length or other fundamental scales. These are open questions in theoretical physics, and further research and advancements are required to deepen our understanding of the nature of the universe at such small scales.