Anything we say virtual nowadways are not real, which means they don't exist. But in physics we have virtual particles that do exist. Virtual particles are subatomic particles that form out of "nothing" for extremely short periods of time and then disappear again.For Example, if you have a huge amount of energy, you can create anything out of nothing for a very very short time, much much less than a second. Heisenberg's uncertainty principle, which explains the virtual particle phenomenon, is most commonly stated as follows: It is impossible to exactly and simultaneously measure both the momentum and position of a particle. There is always an uncertainty in momentum and an uncertainty in position. More importantly, these two uncertainties cannot be reduced to zero at the same time.

One consequence of Heisenberg's uncertainty principle is that the energy and duration of a particle are also characterized by complementary uncertainties. There is always, at every point in space and time, even in a perfect vacuum, an uncertainty in energy and an uncertainty in duration, and these two complementary uncertainties cannot be reduced to zero simultaneously.