The figure eight, when placed on its side, is the mathematical symbol for Infinity. It is also a Mobius strip. If you take a strip of paper and join its two sides forming a ring, you will see that it has two sides - an inside and an outside. But if you twist one end of the strip before you join the two ends, you make a Mobius strip. This is a mathematical shape that has just one side because there is no longer an inside and outside here - the inside and outside are one. If you cut the Mobius strip that you have made length-wise in half all the way through, you don’t get two separate strips of paper like you would if you cut a ring in half length-wise - you get one longer Mobius strip (with two twists in it now).
In the multicolored figure eight in this picture is the first Hebrew letter, Aleph א. The gematria (number value) of the letter Aleph is one - 1. Look at the Aleph in this picture. See how one Yod י in red goes up from the middle of the diagonal yellow Wow or Vav ו, becomes orange, and then curves back to the yellow Wow at the top left. An upside-down Yod י goes down from the middle of the yellow Wow, becomes green, and then curves back to the yellow Wow at the bottom right.
In Sefer Yetzirah, Aleph represents a Breath of Air that goes up and out with the exhale; and down and in with the inhale. Each Breath is one thing made from two halves - out and in. And therefore each breath can be a Wow experience where we become One with the Infinite and the Eternal.