What is everything made of?
Everything is made of accountancy, rates and counts that observers keep about one another, with nothing underneath them. Walk down through a proton. Its mass is a standing cost, the upkeep on a pattern that keeps re-asserting itself. That cost is a rate of repair, the move by which two neighboring observers settle a disagreement. A repair is one comparison between two readings, and a reading is a number an observer holds about a neighbor it cannot see. No material turns up at any step. Space is a count of comparisons, and light is a ripple with nothing to maintain. Lavoisier's 1789 table of elements put light and heat at the top as substances, and he got both wrong. The jar is empty all the way down, and the inventory is complete anyway.
This answer comes from OPH, Observer Patch Holography. OPH is a rigorous, consistent and complete description of the unified, self-creating computational Universe we inhabit. Its consistency is machine-checked: the fixed point at its core is constructed explicitly, and a theory with a model contains no contradiction.
To understand OPH and check every step yourself, start with the free book Reverse Engineering Reality. It builds the theory from the ground up, and the OPH Notebook answers your questions while you read.
read the free bookask the notebookor ask sage:read chapter 35: What Is Anything Made Of?watch a universe make its own particles