Chapter II – Dome Frequencies

What is a Frequency?

First, I had to figure out what a frequency is. According to Wikipedia, there are a variety of frequencies: temporal, spatial, and angular. ¹

Too technical for me.

Basically, a frequency is the number of times something occurs.

In domes – a frequency is how many times an icosahedron edge has been segmented – this makes the dome rounder. To identify the frequency is to know how many line segments/edges are between icosahedron vertices.

What is an Icosahedron Edge?

First – there are three important structural terms that define the platonic solid, Icosahedron:

  1. Triangle Face – the actual two dimensional triangle
  2. Edge/Line Segment – the lines that make up the triangle
  3. Vertices – Where the edges/line segments meet
Icosahedron - Edge, Vertex, Face

Photo Credit – Math.net

So, what is an Icosahedron edge? Essentially, it is the edge/line segments of a triangle face within an Icosahedron or, the edge/line segments between vertices.

Second – are these facts about this platonic solid:

  • An Icosahedron has 20 faces, 30 edges/line segments and 12 vertices.
  • Every one of the 12 vertices are the centre of a pentagon.
  • There are 12 vertices, yes, but not twelve individual pentagons because the pentagons of an Icosahedron overlap each other.
  • The imagine below illustrates how the pentagons overlap each other:

These facts are important because as you increase frequency, the Icosahedron is no longer a platonic solid. All platonic solids are polyhedrons, (meaning many sided shape). But, remember the definition of a platonic solid is that all its angles, edges and surfaces are equal. Once you start expanding the platonic solid by increasing frequency, the angle, edges and surfaces are no longer equal, thus it is no longer a platonic solid.

Most geodesic dome homes are based on the Icosahedron because it is the roundest of the platonic solids. Increasing the frequency makes the shape even rounder. This is why frequency matters.

Why Frequency Matters

It matters because the more frequencies, (meaning the more times an Icosahedron edge has been segmented), the rounder the structure will be.

Our dome will be a three frequency dome, as this is Michael’s favorite.

A one frequency Icosahedron has not been segmented – it is one of the five platonic solids.

A two frequency Icosahedron is dividing all of the triangle edges within an Icosahedron face into two parts – it is no longer platonic solid.

A three frequency Icosahedron is dividing all of the triangle edges within an Icosahedron face into three parts.

And so on….

The first row of images illustrate how a one dimensional triangle is segmented from 1 frequency to 2 frequencies and so on.

Next, the images highlight one triangle face of an Icosahedron, illustrating what happens when the three dimensional Icosahedron is segmented to create higher frequencies that build rounder geodesic domes.

Photo Credit – Pacific Domes

Counting Frequencies

The vertice of a pentagon is another fundamental concept of understanding frequencies. The number of line segments between pentagon vertices defines the frequency.

Photo Credit – Pacific Domes – Dome Book 2 – Page #24

Steps to locating the frequency in the above image:

  1. Locate the two pentagons.
  2. Starting with the left pentagon, find the vertice.
  3. Then count the line segments to the vertice of the next pentagon. (I’ve taken artistic license with a picture from Pacific Domes – Dome Book 2 – Page #24 – I’ve highlighted the line segments between pentagon vertices – red, yellow then green.)
  4. The number of line segments between the two vertices determines the frequency.
  5. 3 line segments = 3 frequency dome.

Conclusion

So, there it is!

Higher frequencies make a geodesic dome home rounder.

When you look at a geodesic dome home – to identify what “kind of” or “how many frequencies” it is – you count the edges/line segments between pentagon vertices!

The next chapter in my blog series on building a geodesic dome home is turning a 3 frequency icosahedron into a geodesic dome home!

S, 📐

References

1 – Wikipedia


Spring of 2020 – Conceptional Ideas Come to Life on SketchUp

Original Design of our 5 Partial Sphere 3 Frequency Icosahedron Geodesic Dome
Original Design

During the spring of 2020 Michael purchased the 3D Modelling Program SketchUp and began designing our 5 Partial Sphere 3 Frequency Icosahedron Dome.

Because of post-COVID inflation rates we are not building the annex and main dome (dome to the left). We have chosen to build the garage and workshop section of the original design, with a studio apartment above to call home.


Updated design of our Dome Home
Updated design of our Dome Home

Interior design of our Dome Home
Interior design of our Dome Home

Two years after he started putting his ideas into 3D form, construction begins with Michael as the one man general contractor.

Michael has designed, researched, organized, been part of or is building every aspect of our dome.

We hope you enjoy this blog series.

You can contact us at info@joyfulstephanie.me for further information or questions.

Stephanie & Michael


Building A 5 Partial Sphere 3 Frequency Icosahedron Geodesic Dome – Concrete Wedges For Foundation Hubs & Family Help

Building A 5 Partial Sphere 3 Frequency Icosahedron Geodesic Dome – Bolting Lower Struts To Hubs, Raising First Triangles & Installing Hub Sets

Building A 5 Partial Sphere 3 Frequency Icosahedron Geodesic Dome – November, 2023 – Building the Dome Structure

Building A 5 Partial Sphere 3 Frequency Icosahedron Geodesic Dome – Winter – 2023/2024 – Building Of The Dome Structure Continues

Building A 5 Partial Sphere 3 Frequency Icosahedron Geodesic Dome – Spring – 2024 – Framing Trapezoids

Building A 5 Partial Sphere 3 Frequency Icosahedron Geodesic Dome – Spring – 2024 – Drone Photos Of Penny Lane

Building A 5 Partial Sphere 3 Frequency Icosahedron Geodesic Dome – Landscaping & Sheathing & Window Framing

Building A 5 Partial Sphere 3 Frequency Icosahedron Geodesic Dome – Construction Of The North Entrance Portico

Building A 5 Partial Sphere 3 Frequency Icosahedron Geodesic Dome – Applying The Elastomeric Membrane

Building A 5 Partial Sphere 3 Frequency Icosahedron Geodesic Dome – Progress From January To June 2025



© Stephanie Wells – Joyful Stephanie – Living an Authentic Life – 2014-2026. Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited.


2 Comments Add yours

  1. Michael says:

    Well organized information on a fairly daunting concept. Am liking this series!!

  2. dvkenobie says:

    Very interesting!
    Sure beats counting on your fingers.

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