Borrowing Energy to Make Particles

The exchange particles are made from ‘borrowed’ energy, borrowed from where? From nowhere! Yukawa used the Heisenberg Uncertainty Principle to establish that a particle of mass-energy ΔE could exist for a time Δt as long as where h is Planck’s constant. This means that a heavy particle can only exist for a short time while a lighter particle may exist for longer.

h is Planck’s Constant, h = 6.63 x 10^-34 J s.

In 1947 the exchange particle of the strong nuclear interaction were observed in a cloud chamber.