The Time Machine is one of the classic and iconic devices of Victorian science-fiction and time traveling is also one of the major themes in Steampunk related fiction. Now most of us will have have heard of and mused on some of the classic paradoxes that happen when one tries to alter the past by employing the time machine.
Now what about the future? There may be paradoxes there, too, unless you subscribe to the many worlds hypothesis. In this case, you could visit the future multiple times and each time you would encounter a different future. It all is directly influenced by the actions you take in the relative Now and the future is constantly changing, new alternatives appear, other possible futures vanish.
The scenario becomes more sinister if you postulate there is only one future. In this case, a time machine can be used to bolt the future in place. You skip a tiny bit into the future, make sure everything happens according to your wishes (getting the winning lottery numbers and things like that) return to the present and watch things unfold. On the other hand, your vision of the future remains localised. You cannot know what greater consequences your actions will have and,to quote Leto II:
To know the future is to be trapped by it.
Yes, a single-path future can be a very unpleasant thing in deed. Especially when you find out that due to some chaotic effects, your carefully laid out plans have some very unwanted consequences in the long run. This leads to more trips into the future to prevent certain things which in turn leads to more consequnces and we have a cascading temporal effect! Oh, technobabble, how I love thee!
Right, so much for some fun fringe physics rant this evening, I shall now go and explore the land of dreams.