A Practical Physics-Checking Workflow for Fiction Writers

When a story includes a fall, collision, explosion, spacecraft maneuver, electrical failure, or even a character carrying a heavy object, a little physical consistency can make the scene feel much more convincing. The goal is not to turn fiction into a textbook. It is to preserve the emotional beat while avoiding details that pull an attentive reader out of the story.

I use a five-step check when revising scenes that depend on physics.

1. Identify the claim the reader can test

Reduce the scene to one plain sentence: “The character jumps from this height and lands safely,” “The vehicle stops within this distance,” or “The sound reaches one character before another.” This prevents a vivid paragraph from hiding the exact physical claim.

2. Choose a model that is simple enough

Most fiction does not need a perfect simulation. A first approximation is often enough: constant acceleration for a short fall, conservation of momentum for a collision, inverse-square reasoning for light, or energy conservation for a pendulum. Write down what is being ignored, such as air resistance, friction, deformation, or reaction time. Those omissions can become useful story details later.

3. Check units before numbers

Unit mistakes are often more damaging than approximate values. Convert everything to one system, label each quantity, and make sure the final unit matches the question. If the scene uses miles per hour but the equation expects metres per second, perform that conversion explicitly. Writers can keep the prose in familiar units even if the calculation uses SI units behind the scenes.

4. Test scale and timing

After calculating, ask whether the magnitude passes a common-sense test. How far does something move during one second? Could a character perceive and react in the available time? Would the released energy cause heat, sound, or structural damage that the scene currently ignores? A rough estimate is usually more valuable than false precision.

5. Revise the constraint, not necessarily the plot

If the original action is implausible, small changes may preserve the intended beat: lower the height, increase the stopping distance, add a safety line, change the material, give the character more warning, or make the environment reduce the force. The calculation should support the story rather than dictate it.

For writers who want a second pass on an equation or image of a handwritten setup, Physics AI at https://physicsai.chat/ can be used as a browser-based worksheet. I find the useful part is not merely obtaining an answer, but comparing knowns, unknowns, assumptions, units, and a final plausibility check. Any automated explanation should still be treated as a draft: verify the equation, inspect the units, and compare the result with an independent estimate.

This workflow works especially well during revision. Draft the scene for character and pacing first, mark any testable physical claims, then check only the details that materially affect what the reader sees or believes. That keeps research bounded while giving the finished scene a stronger sense of weight, distance, time, and consequence.

What physical details do other writers check most often when revising action or speculative scenes?