The symbol \( \varepsilon_0 \) (epsilon nought) represents the
permittivity of free space (also called the
vacuum permittivity), which is a physical constant that describes how electric fields interact with a vacuum.
The formula for \( \varepsilon_0 \) is:
\[
\varepsilon_0 = 8.854 \times 10^{-12} \, \text{F/m}
\]
Where:
- \( \varepsilon_0 \) is the permittivity of free space.
- The unit is Farads per meter (F/m).
This constant is important in electromagnetism, particularly in the equations for electric fields and forces, like
Coulomb's law.