Hmmm, well ... time machines to go one-way into the future are certainly theoretically possible. Even with current technology, it's not too hard to build a machine which will effectively transport you a very short time into the future using the well-established physics of relativistic time dilation, but going any significant time into the future requires getting up to a useful fraction of lightspeed, which is very hard work (beyond current technology) for any significant mass.
The possibility of a time machine going into the past (or returning from the future, which amounts to the same thing) is ... let's just say "much more controversial".
Comments
The possibility of a time machine going into the past (or returning from the future, which amounts to the same thing) is ... let's just say "much more controversial".