Time has three parts- Present , Past and Future. these parts have connectivity. If at a particular moment an object or medium  exits in all three points like present ,past and future point whether these points are far at a string level or from the big bang point  to current expansion point of universe  level  SO for this Object Or Medium has no barrier of Time , Space ,  and Speed . Its means by help of this medium we can travel anywhere in space at any speed , can travel in past or future .
There is only One thing which exit everywhere in universe-  DARK ENERGY.