Helix facts for kids

This cool staircase in the Vatican Museums looks like a helix!

In math, a helix is a special kind of curve that goes around in three dimensions. Think of it like a spiral that also moves upwards, like a spring or a screw. Every helix has a straight line in its center called its axis. The curve always stays at the same angle to this central line. You can find helices everywhere, from tiny DNA strands to huge roller coasters and even in nature!

Different Types of Helices

Helices can be either right-handed or left-handed. This is like telling your left hand from your right hand.

Right-Handed vs. Left-Handed Helices

Imagine you are looking straight down the middle (the axis) of a helix.

• If you turn it clockwise, and it moves away from you, it's a right-handed helix.
• If you turn it clockwise, and it moves towards you, it's a left-handed helix.

Two types of helices shown side-by-side. One is left-handed and the other is right-handed. You can see how they look different from various angles.

This "handedness" (also called chirality) is a true property of the helix itself. You can't just turn a right-handed helix to make it look left-handed. You would need to see it in a mirror!

Many common things are right-handed helices:

• Most screw threads on hardware are right-handed.
• The common forms of DNA (called A-DNA and B-DNA) are also right-handed.
• However, one type of DNA, called Z-DNA, is left-handed!

Understanding Helix Pitch

The pitch of a helix is how tall one full turn of the helix is. Imagine a spring: the pitch is the distance from one coil to the next, measured straight along the center axis.

What is a Double Helix?

A double helix is made of two helices that share the same central axis. They are usually exactly alike and just shifted a bit along the axis. The most famous example is the structure of DNA.

Other Helix Shapes

There are many other types of helices, each with special features:

• A conic helix spirals around a cone shape. An example is the path of a roller coaster that twists around a central point, like the Corkscrew ride at Cedar Point.
• A circular helix is one that has a constant radius, meaning it's always the same distance from its central axis. Think of a perfect Slinky toy.
• A general helix (or cylindrical helix) is a curve where its direction always makes the same angle with a fixed line in space.

Examples of Helices in Real Life

Helices show up in many unexpected places:

• In music, the way we understand different musical notes and how they relate to each other (like the circle of fifths) is often shown using helices. This helps explain how notes sound similar even when they are higher or lower in octave.
• Many things in nature, like the twisting stems of some climbing plants, grow in a helical shape.
• In physics, tiny charged particles moving through a steady magnetic field often follow a helical path.
• The springs you find in pens or car suspensions are also great examples of helical coils.

Images for kids

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  A tiny folded molecular helix, seen through a special microscope.

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  A natural left-handed helix, made by a climbing plant.

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  A charged particle moving in a magnetic field, following a helical path.

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  A helical coil spring.

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  A helix made from wavy X and Y shapes.

See also

In Spanish: Hélice (geometría) para niños