Newman Limit

The theoretical barrier preventing ships from achieving FTL travel within a planet’s atmosphere. The Newman Limit Theory states that multi-dimensional technologies like FTL drives and four-dimensional shields cannot function in flat dimensions or on the surfaces of planets due to a barrier between the third and fourth dimensions, preventing matter in the first three dimensions from affecting matter in any other dimension. This limit is believed to be the result of the gravitational will of the planet, and theoretically any sufficient gravitational force will have a similar effect.

Often confused with the Fernel Limit which concerns similar things.

The Newman Limit was discovered by Douglas Newman, a protegie of Dr. Rupert Python, practical inventor of FTL.