When I was twelve I read the book One Two Three... Infinity by theoretical physicist George Gamow.

In this wide-ranging popular science book Gamow introduced me to number theory, transcendental numbers, the different levels of infinity, genetics, a printing press that produces all the books that have ever been or ever will be printed, four-dimensional space, the origin of the chemical elements, topology, and cosmology.

I was transfixed.  It set the course of my life. 

Gamow was the chief advocate for the Big Bang theory of the origin of the universe.  The main rival for the nature of the cosmos was the Steady State Theory championed by astronomer Fred Hoyle.  

Gamow called the substance that existed right after the Big Bang the “ylem”.   

The Big Bang model has long since won the day and we can see echos of the ylem in the universal background radiation that comes from every direction in the sky and, in a sense, from the beginning of time.  Ironically, Fred Hoyle was actually the one who coined the term “Big Bang” for the rival theory that he spent his life trying to refute.

This is my conception of the ylem.  You could also consider it a picture of the explosion that happened in the brain of a young boy reading about number theory, transcendental numbers, the different levels of infinity, genetics, a printing press that produces all the books that have ever been or ever will be printed, four-dimensional space, the origin of the chemical elements, topology, and cosmology.

Ylem is a usable word in the Official Scrabble Players Dictionary.