there is a constant structure with some activity going on inside it. When von Neumann’s abstract machine reproduced, it made a copy of itself in another region of the plane. Within the “machine” was a horizontal line of squares which acted as a finite linear tape, using a subset of the finite alphabet. It was the symbols in those squares that encoded the machine of which they were a part. During the machine’s reproduction, the “tape” could move either left or right and was both interpreted (transcribed) as the instructions (translation) for the new “machine” being built and then copied (replicated)—with the new copy being placed inside the new machine for further reproduction. Francis Crick and James Watson later showed, in 1953, how such a tape could be instantiated in biology by along DNA molecule with its finite alphabet of four nucleobases: guanine, cytosine, adenine, and thymine (G, C, A, and T).'* Asin von Neumann’s machine, in biological reproduction the linear sequence of symbols in DNA is interpreted—through transcription into RNA molecules, which then are translated into proteins, the structures that make up a new cell—and the DNA is replicated and encased in the new cell. A second foundational piece of work was in a 1945 “First Draft” report on the design for a digital computer, wherein von Neumann advocated for a memory that could contain both instructions and data.'4 This is now known as a von Neumann architecture computer—as distinct from a Harvard architecture computer, where there are two separate memories, one for instructions and one for data. The vast majority of computer chips built in the era of Moore’s Law are based on the von Neumann architecture, including those powering our data centers, our laptops, and our smartphones. Von Neumann’s digital-computer architecture 1s conceptually the same generalization—from early digital computers constructed with electromagnetic relays at both Harvard University and Bletchley Park—that occurs in going fro