That first contraption from 1947 was about the size of a small child’s hand, but the part that really matters, the transistor itself, was perhaps about a centimetre. Now consider what happened in the following 75 years. By the time of the Intel 4004, the first modern computer chip, in 1971 there were just over 2,000 transistors crammed into roughly the same area, each single one about the size of a red blood cell. Roll forward to the early 2020s and smartphone processors could fit around 12 billion transistors into an area slightly smaller than a square centimetre.
