The fine structure constant (α) is a dimensionless quantity that characterizes the strength of the electromagnetic interaction between charged particles. It is defined as α = e^2/(4πε₀ħc), where e is the elementary charge, ε₀ is the vacuum permittivity, ħ is the reduced Planck constant, and c is the speed of light.
The connection between the fine structure constant and virtual particles is somewhat indirect. Virtual particles are entities that arise in the context of quantum field theory when calculating interactions between particles. They are not directly observable and do not exist as independent, isolated particles in the same way as real particles.
In quantum electrodynamics (QED), which is the quantum field theory describing the electromagnetic force, virtual particles play a role in the calculations of various physical quantities. They are involved in the so-called vacuum polarization and electron self-energy corrections, which contribute to the overall value of the fine structure constant.
The Heisenberg uncertainty principle is a fundamental principle in quantum mechanics that states a fundamental limit on the precision with which certain pairs of physical properties, such as position and momentum, can be known simultaneously. While the uncertainty principle is related to the existence of virtual particles in quantum field theory, it does not directly determine the value of the fine structure constant.
To summarize, the fine structure constant is not based on a specific time interval of electromagnetism, but rather it emerges as a fundamental constant that characterizes the strength of the electromagnetic interaction in the framework of quantum electrodynamics, taking into account various quantum effects such as virtual particles.