The thing is that a lot of Traveller tech throws logic and consistency off the table, but at great enough conceptual distance from ordinary circumstances that it's possible to (mostly) ignore it.
Just for example, the reactionless thrusters used in most versions of Traveller violate the conservation of momentum, one of the core principles of physics. See the copious recent debate about the EmDrive for details. It also means that, because kinetic energy goes up as v^2, I can always find a reference frame in which an accelerating ship is gaining more kinetic energy than its power plant is supplying.
The side effects of this incongruity show up in-meta-universe with the great "near-c rocks" debate. It's trivially easy to strap a Traveller thruster drive to a rock in the Oort cloud and accelerate it at 1G straight into the mainworld. It will arrive at some large fraction of c, with kinetic energy sufficient to crack a planet's crust open. Again, *anybody* with a starship, or even a lifeboat, can do this. And there are few good defenses. So why is the military history of known space not just a series of horrible stories about shattered, lifeless worlds? Why doesn't the Ine Givar use this to take out half the Imperial worlds in the Marches?
Similarly, show me a CG technology that requires constant power input in a given g-field, and I will happily use it to create a free-energy generator using a classic perpetual motion "unbalanced wheel" that actually works.
Further, I can choose a reference frame in which a ship executing a jump appears at its destination before leaving its origin. I could use this to send a message "back in time" (from the ship's point of view) e.g. warning of a hazard encountered on exit from jump. And what if the crew then decides not to jump?
Traveller physics is deeply, fundamentally broken. It is a testimony to good game-design choices that the brokenness is mostly easy to sweep under the rug.