That's just plot-no-jitsu-super-device to allow story to progress. While there have been cases of reported anomalies with little to no proof (people travelling through time and whatnots), there is always the time paradox thing which leads to many questions and then you have that gargantua in this show to fix everything in a "split second"
everyone always speaks about the dimensional thing as a close loop kind of stuff but I have yet to see any proof to this. Although I bet if there was one, we will have technology to start playing with the space time continuum.
Below is an infographic for anyone confused though about the timelines.
And I just like to mention that I like how this show explains relativity though. the part about waiting 23 years really crack me up haha.