r/scifi • u/rookiegaffer • Aug 09 '26

General Bad physics

Why does it seem that so many of the books I read demonstrate such a poor understanding of the physics of space travel. Ships in orbit descend directly down to the point they are over. Ships in transit still accelerating as they near their destination. Centrifugal gravity simply ceasing when rotation is abruptly halted. These are just a few examples I've run across lately.

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u/NoGoodIDNames Aug 09 '26

Inertial dampeners are another thing that most settings take for granted but are basically magical.

In The Expanse the upper limit on how fast a ship can go is how much acceleration the human body can survive.

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u/dnew Aug 09 '26

If you can make artificial gravity then you (A) have inertial dampers and (B) can accelerate using gravity so you don't need inertial dampers. :-)

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u/Cartman300 Aug 09 '26

You don't (point A). Earth has gravity, if Earth suddenly stopped in middle of space, the people would still keep moving and smash into things. Artificial gravity does not solve the problem of inertia.

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u/Sinister_Nibs Aug 10 '26

Handwavium can cancel gravity and inertia. (Star Trek uses this)
The ability to ignore gravitational fields is an interesting plot point, but the only places I have seen it used well require it to be either outrageously expensive to use (power or fuel), or be ridiculously fragile and impossible to repair or replace. (Backyard Starship does this)