Belthasar > all other fictional engineers ever. Well, at least in terms of skills. Except maybe Bevel Lemelisk, but that's not even the same galaxy. But Scotty's still my favorite engineer.
For reference, Bevel Lemelisk is the asshole primarily responsible for designing the Death Star. The New Republic gave him the death penalty for this crime, but he had already been executed and had his soul installed in a clone seven times by the Emperor, whose methods of execution included such fantastically merciful things as being eaten by rabid pirahna beetles, kicked out an airlock, and thrown in hot boiling lava. Such a nice guy, that Palpatine.
Also, scientists at the University of Pittsburgh have actually developed a way to store antimatter. The particles, of course, are highly unstable, and have half-lives almost too small to measure. There's a good chance that by the year 2300, we've already figured out a way to suspend antimatter in stasis until it's needed, as well as utilize directed energy to propel the blast where we want it. This could work both as a missile weapon and as a thrust mechanism. One kilogram of matter and antimatter reacting together will release ~90,000 TJ of energy -- that's within the same power range as the most powerful nuclear weapons we've ever tested. Enough of this to fill a ship's drive, coupled with the capability to direct the energy release and withstand the g-forces of such speeds, might get the ship going fast enough to distort time, and some other mechanism could take over from there to propel the ship into four-dimensional space. That would require the ability to direct gravity sufficiently to bond the entire ship's chassis and engine together as one piece, to ensure maximum resilience against all external force. The reasons for this are twofold. One of them, I already listed. The other one is that if Einstein's theory that objects gain mass as they gain energy, since the two are interchangeable via E=mc^2, holds true and is not just a characteristic increase in momentum proportional to the kinetic energy of objects, then as the Epoch or Neo-Epoch approached the speed of light, or whatever imperceptible barrier must be surpassed to engage in time travel under Belthasar's principles, the ship would gain mass. More mass means more gravity, which, at a great enough velocity, would mean that the ship would collapse in on itself. A complete understanding of gravity, especially quantum gravity, is therefore required to do anything on the magnitude of what Belthasar did.
And he did.
Which means he is, as ZeaLitY aptly worded it, one hell of an engineer.
