They're normal. When our first ancestor stood upright, a right angle was formed with the ground. A hand axe, a knapped stone lashed at right angles to a branc

They're normal. When our first ancestor stood upright, a right angle was formed with the ground. A hand axe, a knapped stone lashed at right angles to a branch. Some say fire or dogs are humanity's first and greatest inventions - but we only domesticated those. I say weaving: an extraordinary crossing of threads at right angles that magically support each other, clothing that is the biblical coming-or-age of human-kind, fabric that drapes organically (and is still used today, even as threads become artificial), rope, leaves for shelter, even decorating hair. And it directly lead to the single greatest invention of our time, that binds all things together: gaffer tape.