ELI5: Explain Like I'm 5

Frenet-Serret formulas

Imagine you are playing with a toy car and you push it along a curved track. As the car goes around the track, it changes direction and speed. You can use the Frenet-Serret formulas to describe how the car moves along the track.

The Frenet-Serret formulas are a set of equations that help us understand the motion of an object as it moves along a curved path. They tell us how the object's velocity, acceleration, and curvature are related to each other.

In simpler terms, these formulas help us understand how an object is changing direction and how fast it is moving as it moves along a curved path.

To understand this, we have to first understand two important concepts: tangents and normals.

Imagine drawing a line tangent to a point on a curve. This tangent line is the line that "touches" the curve at that point and is parallel to the curved path. The tangent line gives us the direction of motion at that point.

Now imagine drawing a line perpendicular to the tangent line. This line is called the normal line and is perpendicular to the tangent line, representing the direction of curvature at that point.

Using these concepts and formulas, we can describe how an object moves along the curve by looking at how its velocity and acceleration are related to the tangents and normals at various points on the curve.

Overall, the Frenet-Serret formulas help us understand the complex motion of objects along curved paths, which is important in fields like physics, engineering, and robotics.