The uncertainty principle is a fundamental principle in quantum mechanics that applies to all particles and all scales, not just a pre-Planck era of creation. It is a fundamental aspect of the quantum nature of the universe and continues to be relevant and applicable in our understanding of quantum phenomena.
The uncertainty principle, formulated by Werner Heisenberg, states that certain pairs of physical properties, such as position and momentum, cannot be precisely known simultaneously beyond a certain limit. It is not a principle that is limited to a specific era or stage of the universe's evolution.
The Planck era, which refers to the earliest moments of the universe shortly after the Big Bang, is indeed a time when the quantum nature of the universe becomes important. At such high energies and small scales, the effects of quantum mechanics, including the uncertainty principle, become significant. However, the uncertainty principle is not exclusive to that era. It applies to all particles, at all scales, throughout the universe.
Whether we are considering particles at the subatomic level, atoms, ions, or even larger systems, the uncertainty principle remains a fundamental principle in understanding their behavior. It plays a crucial role in the foundations of quantum mechanics and has been experimentally confirmed in various scenarios.