Definition:Helix/Pitch

Definition

The pitch of a helix $\HH$ is the distance by which a point on $\HH$ is displaced in making $1$ revolution around the axis of $\HH$ in a direction parallel to the axis.

Examples

Circular Helix

Consider the circular helix $\HH$ whose parametric equation is given as:

$\begin{cases}

x & = a \cos t \\ y & = a \sin t \\ z & = b t \\ \end{cases}$

The pitch of $\HH$ is $\dfrac {2 \pi} b$.

Also see

• Results about helices can be found here.

Linguistic Note

The word helix comes from the Greek ἕλιξ, which means twisted or curved.

It is pronounced hee-lix.

The plural of helix is helices, which is pronounced hee-li-seez.

Sources

• 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): helix
• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): helix