Next to 3D, you can also imagine the world in pyramidal dimensions.
The word dimension comes from Latin meaning to ‘measure out’ and so far we only needed three of them to discuss anything spatial. Yet the particulars of space can be measured out in more ways than just 3D. By creating a different system it can become obvious that the human brain is capable of recognizing more than one system.
The most used visual tool for expressing dimensions is the cube. Six equal fields form the outside of a cube, and each specific field can be declared as left, right, up, down, front, or back. Together, they create three dimensions in total.
Imagine standing inside that cube as if it were a room; walls on four sides, a ceiling above, the floor below. How easy would it be to draw a line from one floor corner of the room to the exact opposite ceiling corner? Quite easy! And it can be done four times without a problem. Voila, we have our four-dimensional system, different from the usual 3D. If you want, time can get added as the fifth dimension.
In the image below, each dimensional line is made up of one red section and one green section, all starting in the corners of the cube.
While standing in the middle of a room, it is easy to imagine the four dimensional system with ourselves as the center. Notice how it is truly distinct from the three-dimensional system.
Did you see the pyramids already? The green lines form a pyramid and so do the red lines. Next, there are four more pyramids visible in the cube, each with two green and two red lines. There are therefore six pyramids in total, appointing the 3D system as an inward system, whereas the eight corners of the pyramid dimensions point outwardly, away from the center.
The four-dimensional system is not used in our culture; we haven’t invented easy words for these directions. One has to combine words from the three-dimensional system — for instance, left-front-up — to express one such direction. Some cultures do ascribe importance to four or eight directions. Examples are mandalas that can feature four or eight central aspects.