Negative numbers do not exist. There are only positive lengths in different directions. Humans will simply turn a ruler into the opposite direction, if they pretent to measure a negative quantity. But all these quantities still are positive, of course.

Negative numbers do not exist. But intelligent starfishes exist. Intelligent starfishes describe their mathematical world by using the three directions of their tentacle arms. And these three directions are equivalent and positive, of course.

In this book intelligent starfishes describe the Special Relativity of Einstein. This description is based on their mathematics of three directions, which is the mathematics of a relativistic spacetime plane. These three directions are: the direction of time, the direction of space, and the direction of light, of course.

Aeons ago, ages still will come and go, a young, shy, wise, and very, very far-sighted starfish scientist roamed through the bizarre Gog Magog underwater hills, climbed an underwater tree and invented the Dirac algebra of starfishes.

By using this Dirac algebra of starfishes relativistic time dilation, length contraction, and Lorentz transformations are explained. And this mathematics is that simple and easy that readers will not have to struggle with the physics. They only have to struggle with the text, because ... sdrawkcab nettirw si tI.