A possible explanation for "the future" is a dimensional theory called the Future Dimension. A Future Dimension is a dimension that portrays the future. When "traveling" into the future, you may only enter into a different dimension rather than accelerating through time at a fast pace.
This Future Dimension is essentially a Time-Locked Dimension of whatever period of time you happened to stumble upon.
A Future Dimension may contain constructs, as well. These may be able to be taken back into the Core Universe, but very few would be willing to admit a construct from the future exists in our current time period, let alone having visited a Future Dimension.