[Spaceships] Reactionless Drives, Pseudovelocity, and NOT breaking a setting (much)

[Emerald Cat]

Originally Posted by Varyon

First off, hyperspace exists and has something of an atmosphere, called aether.

This is an interesting approach. It sounds like weapons would work more or less normally in this setting. Political borders would arise naturally. I favor "shortcut" type hyperspace based comms and FTL myself because it allows the PCs to go interesting places while preventing world breaking shenanigans. And also neatly resolves the Fermi Paradox in a way that doesn't preclude galactic civilizations.

Building a reactionless drive that doesn't violate the (known) laws of physics is difficult.

But it is quite feasible to prevent "true velocity" reactionless drives from breaking the setting with two simple rules:

• Energy and Angular Momentum are Conserved: you must pay an energy cost equal to the change in KE of your ship + PE due to changing your location. Also makes accelerating anything to c exorbitantly expensive.
• Velocity is Continuous: you can't just instantly jump to the desired velocity. You must accelerate. This helps reactionless drives mesh with human intuition while making them harder to weaponize.