Definition:Helix

Definition

A helix is a twisted space curve whose tangent makes a constant angle with a fixed line.

Axis

The axis of a helix $\HH$ is the fixed line to which the tangent to $\HH$ makes a makes a constant angle.

Pitch

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.

Circular

A circular helix is a helix $\HH$ which lies entirely within the surface of a circular cylinder $\CC$ such that the axis of $\HH$ coincides with the axis of $\CC$.

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