I watched a YouTube video by Steve Mould, in which he explained and demonstrated a type of structure called tensegrity. This was completely new to me and I found it fascinating. For example, here is a plant stand you can buy on Amazon
At first sight this seems impossible; how can the top magically levitate? Steve Mould explained it by starting with a 2-D version, something like this.
The black bars are rods and the red lines are wires. If you try to push the top down, the wire EF will be stretched and will pull the top part back up. If you try to push the top to the right, the wire AC will be stretched and will pull the top back into position. Similarly, if you try to push the top to the left, the wire BD will be stretched and will pull the top back into position.
The 3-D version in the plant stand follows the same principles. Although it has four radial wires it's still possible to build such structure with only three wires altogether and you can even buy a Lego-compatible version of this design.