The tetrahedron balloon is a very simple balloon to build. This balloon shape became known to the general public through the attempt to build a balloon with the materials that were available to the inhabitants of Nazca and the book by Jim Woodman - Nazca:Journey to the sun, which describes this attempt.

As great as this idea is, it should not be adopted uncritically. The Nazca balloon proves that the inhabitants could have built a balloon, but not that they did. There is a critical article by Katherine Reece - Grounding the Nazca Balloon on the subject.

But it remains a great story, and building a tetrahedron balloon is still an interesting experiment, especially because of the differences to the spherical balloon. And to convey to children and young people the idea that looking into the past from our present-day perspective is an approach that can lead to false insights, and not just in the case of the Nazca balloon.

Only carry out this experiment if you know what you are doing. Depending on which heat source you use for heating, there is a risk of fire! If you use foil instead of paper, you should keep it away from your head and airways, otherwise there is a risk of suffocation! And if you are flying the balloon outdoors, observe the regulations in your country. In particular, it is usually forbidden to attach a heat source in the form of an open flame to the balloon or to attach solid parts to the balloon. The adhesives used for construction should not be left unsupervised by children. These instructions should supplement, not replace, your own assessment of the risks and measures to prevent them.

Make a rectangle with an aspect ratio of 1:2 from floral silk or another lightweight airtight material.

Glue the rectangle together overlapping on the two narrow sides to form a short tube.

Now seal the open ends of the tube by gluing them together.

Now you have a tetrahedron, a body with four triangular faces.

To create an opening through which the tetrahedron balloon can be filled with air and heated, cut off one of the corners.

Now heat the tetrahedron balloon with a hairdryer or hot air blower. Take care not to touch any hot parts that could burn you. When the tetrahedron balloon pulls upwards, you can let it go and it will rise.

Experiments ←