Andrew King

Tunnelling like this is a direct consequence of the famous Uncertainty Principle. This is the conventional English translation of the original German name Ungenauigkeitsprinzip, which would have been far better translated as something like ‘Inexactitude Principle’, or ‘Imprecision Principle’. (The conventional name has led far too many innumerate English-speaking writers to the erroneous view that physics is somehow fundamentally vague, or worse, simply a cultural concept.)

We have met the Uncertainty Principle earlier in this chapter. It says that the imprecision in the momentum of a particle and in its position cannot both be arbitrarily small. The degree of smallness specified here tells us that this principle is only important on scales smaller than the size of an atom.