Here's why:

* Inertial Frames: In an inertial frame of reference (one that is not accelerating), objects move in straight lines at constant velocities unless acted upon by a force.

* Rotating Frames: In a rotating frame of reference, such as the Earth, an object moving in a straight line from the perspective of an observer in the rotating frame will appear to curve due to the rotation. This apparent curvature is caused by the Coriolis effect.

Examples where the Coriolis effect is significant:

* Weather Patterns: The Coriolis effect is responsible for the rotation of large-scale weather systems like hurricanes and cyclones.

* Ocean Currents: Ocean currents are also influenced by the Coriolis effect, contributing to large-scale patterns of circulation.

* Projectile Motion: The Coriolis effect can influence the trajectory of long-range projectiles, such as artillery shells or rockets.

* Foucault's Pendulum: This classic experiment demonstrates the Coriolis effect by showing the rotation of a pendulum's swing plane.

Key Points:

* The Coriolis effect is an *apparent* force that arises from the motion of an object in a rotating frame of reference.

* It is not a real force in the sense of gravity or electromagnetism, but rather a consequence of the observer's position within a rotating frame.

* The Coriolis force is proportional to the object's velocity and the angular velocity of the rotating frame.

Let me know if you have any other questions.