Interesting topic. Personally, I think it's thinking too high to proclaim that you have found we live within an universe that "runs" in parallel with another, considering that practically we don't know anything about our universe. We still don't even know what happens with the matter absorbed by dark holes, we haven't researched how wormholes might work or even if they exist (it's been said a wormhole could grant matter instantaneous teleportation between two parts of the universe very distant one from the other), we don't know how quasars works and if it's possible their light could go faster than normal light (another theory I heard over the years). Heck, even when a couple of weeks ago a group of scientists said they measured light moving faster than 300.000 Km/s, it was featured in the mass media as a breakthrough discovery, it was quickly dismissed by other scientists that the experiment had been seriously flawed, nobody took care of talking to the media again and saying: "Hey, it could exist an error in their argumentation".
The theory of multiple universes makes sense when formulated in the way that multiple different
universes could exist, but parallel ones... I think those guys are talking about infinite universes which contain different versions of the same moment in time, but what is the duration of that moment, 1 second? 1 nanosecond? 1 minute? A day?. OK, you have proved the thing with mathematics, now try to explain it in a way that makes sense outside of numbers. We can't almost understand how simple things work, even less something so complex as an universe. Even if we understand it (impossible I'd say), we'll still be asking ourselves: "But, is there something BEYOND?"
Time travelling might be possible to the past, providing you maintain certain kind of link or portal with the exact moment in time from where you took off. To the future it would be a suicide, you would land in a different moment in time everytime, in one you witness the Third World War, in the other, you see people travelling to Mars... and where are only talking about things that people can influence with their work and free will, who knows what could be happening in the universe, we could have been hit by that comet coming beyond the Kuiper Belt, which is currently the biggest object in the Solar System.
Wow, longest post ever, and everything is probably wrong
. Those things are truly fascinating.