A classic Galton board with pegs and balls generates a pattern from randomness. In the quantum version — Jiuzhang 4.0—balls are replaced by photons. They travel through a maze of 8,176 waveguide paths, and photometry (precise flash counting) records the final pattern. The chip itself is cooled below interstellar temperatures to suppress thermal noise.
According to the Standard Model, each particle of light takes all paths at once, like a ball instantly smeared across the entire board. A regular supercomputer would have to check more possibilities than there are atoms in the universe, taking $10^{42}$ years. Jiuzhang delivers the answer in 25.6 microseconds. Engineers used "squeezed" light to eliminate noise, and randomness turned into computational power, just as entropy, which usually brings disorder, here generates order. The term “quantum supremacy” was coined by [scientist:John Preskill]. This step brings closer photonic computers capable of designing drug molecules.
If the El Capitan supercomputer had started crunching numbers at the Big Bang, by now it wouldn't have completed even a fraction of what Jiuzhang 4.0 does in 25 microseconds.
Instant computation, like in "Star Trek", but in a real lab chip.