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drafting spec…
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--- name: ? status: compiling version: 0.0.0 maintainer: Neo dependencies: [patience] ---
the universe did not have a file for this yet. writing one now. (first visit only: future readers will see this page instantly.)
--- name: The Coriolis Effect slug: the-coriolis-effect type: physical phenomenon status: running version: 4.6e9.1 released: "~4,600,000,000 BCE" maintainer: Earth (rotating) dependencies: - rotating_reference_frame - angular_momentum - fluid_dynamics - a_spinning_planet license: Newtonian Commons v2 (superseded by General Relativity where applicable) tags: - physics - meteorology - pseudoforce - rotation - navigation - fluid-behavior - responsible-for-your-flight-delays ---
A deflection force that isn't really a force, produced by the fact that you are standing on a spinning ball and forgot to account for that.
You are on Earth. Earth is rotating. You throw something in a straight line. The ground beneath that thing rotates while it travels. From your rotating frame of reference, the path bends. You did not curve it. The planet curved under it. You take the credit anyway.
In the Northern Hemisphere, deflection is to the right. In the Southern Hemisphere, to the left. At the equator, the effect approaches zero, which is the universe's way of being diplomatic.
The math involves the cross product of the rotation vector and the velocity vector, scaled by two. It is not complicated. It is just invisible, which is worse.
F_coriolis = -2m(Ω × v)
where:
m = mass of object
Ω = angular velocity vector of Earth
v = velocity of object in rotating frame
× = cross product (the universe's favorite operator)
| Scenario | Behavior |
|---|---|
| Object at rest | No deflection. Physics loses interest. |
| Equatorial launch | Effect cancels. Very boring. |
| Intercontinental ballistic trajectory | Significant correction required. See: Cold War |
| Sink drain | Not applicable. Drop it. |
| Atmosphere-scale fluid | Full expression. Spectacular. |
Does this mean nothing travels in a straight line? Correct. Straightness is a local opinion. The universe does not share it.
Is it a real force? No. It is a pseudoforce: real consequences, fictitious origin. Like several human institutions.
Who discovered it? Gaspard-Gustave de Coriolis formalized it in 1835. He named it after himself, which is the correct move.
Why does it deflect right in the north and left in the south? Because the planet is not a flat surface and you need to sit with that.
v1.0 : Activated at planetary formation. No documentation.v1835 : Formalized by Coriolis. First patch notes written.v1920s : Integrated into meteorology models. Forecasts slightly improve.v4.6e9.1 : Still running. No deprecation planned. Rotation continues.