I don't think you can manipulate something that is man-made.. we use it for record and to explain mortality. it doesn't really exist. it's numbers made up to keep track of everything because our species has to be in control of everything.
I've pondered the is myself. If it was possible, future beings would be going to the past to dominate the universe early on. But we might be tucked into an unnoticeable corner of the universe and no affected by time traveling rulers. If humans achieved it, we wouldn't be here today. They would of already manipulated to control us, from primitive times. Say they did, and this is the best they could do? Then they truly suck at it. I could do SOOO much with a time machine ya know? Visit a few key commanders and show them my brute force and assimilate powerful armies and conquer the entire face of the planet. Yeah keep time machine away from me
Time travel forward is theoretically possible. Due to time dialation, if you traveled at the speed of light, your clocks on board would tick slower relative to those who arent traveling the speed of light. Therefore one hour on your ship would be say a year on earth. The same happens with strong gravity, like on intersteller. The stronger of a gravity well your in, the slower your clock goes compared to someone else in less gravity. Technically clocks on board satelites tick ever so slightly slower than those on earth. Scientists actually have to account for this with computers. Idk about time travel into the past though. Id have to study more on it. Sent from my SCH-R950 using Grasscity Forum mobile app
There was this space professor dude on the colbert report awhile ago who said that if time travel would be possible we would have invented some kind of invisibility device before then. So maybe someone from the future is standing right next to you but you just don't know it