There are different kinds of balsa wood. The lightest variety is so porous and the cell walls are so thin that around 75% of its volume is air. This is evident from the greatly enlarged photograph of its internal structure shown here. No wonder a cubic meter of such wood weighs only about 40 kilograms.
Compare it with the black ironwood which has a density of 1,490 kilograms per cubic meter. Now, here’s something to wonder about: The black ironwood which comes from the South African tree of the same name, has a specific gravity of 1.49. This means that unlike all other kinds of wood, it would sink in water.
The balsa wood is an excellent construction material for model airplanes, though nowadays, it is being substituted by Styrofoam.
- Which are the tallest plants and trees in the world?
- Why are some plants insectivorous, or carnivorous?
- Why do trees stop growing after reaching a certain height?