In certain cases quantum fluctuations amplified during inflation may becomeextremely large. They may considerably increase the initial value of the scalarfield which drives inflation. The probability of such events is very small, butthose rare parts of the Universe where it happens begin expanding with a muchgreater speed. This creates a lot of new space where inflation may occur, andwhere large quantum fluctuations become possible. Instead of the universe looking like a single expandingball created in the big bang, we envisage it now as a huge growing fractalconsisting of many inflating balls producing new balls, producing new balls, adinfinitum.
Eternal inflation implies that the universe as a whole is immortal.
Eachparticular part of the universe may appear from a singularity somewhere in thepast, and it may end up in a singularity somewhere in the future. However,there is no end for the evolution of the whole universe. The situation with thebeginning is less certain. It is most probable that each part of inflationaryuniverse has originated from some singularity in the past. However, at presentwe do not have any proof that all parts of the universe were createdsimultaneously in a general cosmological singularity, before which there was nospace and time at all.