Dr. Stone is a creative shonen series that puts science and innovation at the fore. Reawakening after all of humanity was frozen in stone, Senku uses his incredible brain to re-invent humanity's best creations.
With Season 2 just beginning, now is a fine time to review what Senku has accomplished so far in rebuilding civilization from scratch.
Senku's Bright Invention: The Lightbulb
Senku needs a way to keep the Kingdom of Science running even in the dark of night, and he's got the solution: lightbulbs. Making a stone spear or a clay pot is one thing, but a lightbulb? Such an item is rather delicate, and its raw materials are nowhere to be found. Fortunately, Senku and Chrome soon recruited old man Kaseki to their team, and being an expert craftsman, Kaseki was able to blow some glass and make the bulbs Senku needed.
Next, Senku extracted metal from nearby rocks and melted the metals down into filaments, and he even used a pump to remove the bulbs' air. Once all that was hooked up to Senku's power generator, his lightbulbs glowed like a second sun.
Senku's First Major Invention: The Revival Fluid
Senku wouldn't have gotten very far without this particular innovation. He freed himself from the stone at will, but without some allies, he made little progress. Senku toiled endlessly to find a fluid that could undo the mysterious petrification, and a nearby cave had the solution. Nitric acid and alcohol are the keys, and once this formula is poured on sparrows or people, a chain reaction begins in the stone to free the organism inside. Senku brought back Taiju, his brawny classmate, to get some help rebuilding humanity.
Then he used it on Yuzuhira and Tsukasa, though the latter case ended up as a rather mixed blessing. Now Tsukasa is using the miracle fluid to revive tough young adults and build an empire based on nature's laws of freedom, devoid of mankind's laws and institutions, launching the Stone Wars.
Senku's Invention Of Power: A Hydroelectric Generator
Senku had already invented a hand-powered electric generator that allowed him to fuel his lightbulbs. Once Senku won over the entire village, he had more manpower at his disposal, and that meant scaling up the Kingdom of Science's energy production to match. Kaseki and Chrome built a water wheel to turn a shaft without Senku's aid, and Senku hooked up his generator and used new pistons and gears to make the stone world's first-ever hydroelectric power station.
Senku proudly announced that the age of human labor was over, and this mighty station would juice up Senku's newest, most energy-hungry inventions yet. Just in time, too, because Tsukasa's army was looming on the horizon.
Senku's Medical Invention: The Sulfa Drug
Herbs have always been available for medicinal purposes, and many pre-industrial societies around the world knew which plants could be used to cure everyday ailments, from insomnia to stomachaches and acne. But Ruri, the Ishigami village priestess, had pneumonia, and that called for a stronger kind of treatment.
Senku busted his hump gathering the ingredients to make a generic but powerful sulfa drug, and he and Chrome risked their very lives to gather the right acids, herbs, powders and more. Making glassware was also a must, and that's where Kaseki came in. Senku was no doctor, but he knew the basics, and at last, he delivered the white powder drug to Ruri just in time. Her deadly infection cleared right up, and Senku became the village hero.
Senku's Communication Invention: Walkie Talkies
Senku had already done the impossible by inventing glass, ramen, katanas, powerful antibiotics, and even gas masks and electricity. But could he make a cell phone? Yes, actually, though his invention was more akin to a walkie talkie. The battle against Tsukasa's Empire of Might would be a steep challenge, and remote communication was a must if Senku's allies wanted to coordinate their efforts and capture Tsukasa.
Senku used every trick in the book and emptied every shelf in his warehouse to build functioning walkie talkies, from gold wire threads to primitive plastic speakers to vacuum tubes, and more. He needed the entire village to work by his side, from the children threading gold strands from the cotton candy machine to Kaseki forging yet more glass and Magma using his great strength to mine some much-needed tungsten to make filaments for the vacuum tubes.
At last, the work was done, and for the first time ever, the Ishigami villagers could hear a person's voice remotely. Senku really outdid himself this time.