There is a big difference between the temporal modulator that lets you connect to websites in the past and a sci-fi style time machine for biological time travel. The first one will come a lot sooner and may have already been invented. I don't know who would have done it though, they don't tell me anything.
@sevensixtwo & @Howl0 - You know, I think there are perhaps thousands of time machines (at least) throughout the universe that have already been made, yes, even the sci-fi style ones.
There could even have been time machines dating as far back as ancient Sumeria and Egypt. Yes, it may seem like sci-fi to think that it happened in ancient times, but take a look at the Great Pyramids in Egypt. These pyramids would be very difficult, if not, impossible to reconstruct at such precision given the mainstream technology we have today. They had to have been built with much more than just manpower and simple tools.
What motive did john have in coming to post the machine and its schematics?
John outlined his future. Then he put put on the internet the tech to get there - while the capitol of research power is in the hands of darpa. He ensured, if he was true, that our government gained the power first to this tech, and early enough to conceal its existence from us. In the end of his official threads, self disclosed military and CIA persons joined the discussion.
He clearly had to know this would have happened. So then, what was his goal in that?