How did the events at the end of Cage of Eden occur?
It is never explained in the manga how they get 


   to the future.


When they describe the incident, it looks like a wormhole that caused a big disruption in time.


  In physics, an Einstein-Rosen Bridge (or wormhole) is a hypothetical topological feature of spacetime that would be, fundamentally, a "shortcut" through spacetime.[ref]