Borrowing+Energy+from+the+Future


 * Borrowing Energy from the Future **

The uncertainty principle does not necessarily have to refer to that one pair of values which are velocity and position. It can refer to energy and time as well. The shorter the time interval, the wilder the fluctuations in energy. This results in a simple and beautiful consequence: that particles can be created out of nothing.

In the quantum realm, the time scale of events is very short. The number of times that a proton can travel from one side of the atomic nucleus to the other in a single second is 1022. This short time scale allows particles such as protons and neutrons to utilize the uncertainty principle in a crucial way. They can borrow energy from the future (literally nowhere) for a short duration provided the energy gets paid back before the uncertainty principle is violated. The shorter the time the energy is needed for, the more can be borrowed.

A particle called a pion, which is responsible for holding protons and neutrons together can be created by a nucleon (either proton or neutron) which borrows enough energy from its surroundings to create it. The pion then jumps to another nucleon where it vanishes again.

In a similar way, the EM force between charged particles can be seen as the exchange of such a photon, which can be called a messenger particle or virtual particle. It is different from a real photon which may keep its energy for as long as it likes.

Even a vacuum is full of activity and is not exactly empty. Energy is borrowed from the future to create a matter particle and antimatter particle, which collide in a process called pair annihilation to form energy again (through e=mc2), returning the energy borrowed. A vacuum can be said to contain matter and antimatter particles which are constantly created and destroyed all the time.