Why is a perfect vacuum impossible in scientific nature?

Answer 1

Your question is a bit odd since it asks about scientific nature as if there exits some other kind, such as unscientific nature. In any event, random thermal motion tends to cause the diffusion of various gases and particles into every available space. Inter-galactic space is very close to a perfect vacuum, but even there, some very low density of particles can still be found. After all, stars constantly emit particles along with light, and those particles go everywhere.

Answer 2

A perfect vacuum is impossible in scientific nature because even in the emptiest space, there are still quantum fluctuations and virtual particles that constantly pop in and out of existence. Additionally, achieving a perfect vacuum would violate the Heisenberg Uncertainty Principle, which states that it is impossible to simultaneously know the exact position and momentum of a particle.