matter waves leak from the atomic nucleus

An example of metaphor used in a scientist's writing:

"On the other hand, the ordinary mechanical conceptions completely fail to provide us with a description of the course of the disintegration process [of the nucleus], since the field of force surrounding the atomic nucleus would, according to these ideas, prevent the particles from escaping the nucleus. On the quantum mechanics, however, the state of affairs is quite different. Though the field of force is still a hindrance which, for the most part, holds the matter waves back, yet it permits a small fraction of them to leak through. The part of the waves which escapes in this way in a certain time gives us a measure of the probability that the disruption of the atomic nucleus takes place during this time."

Bohr, Neils (1934) Atomic theory and the description of nature. Cambridge University Press