The protagonist of the Dr. Stone series is Senku Ishigami, a gifted young scientist. He revives thousands of years after a mysterious catastrophe turned everyone on Earth to stone. Senku and his new friends decide to start from scratch and build a new society. He uses his scientific and engineering knowledge to create cutting-edge technologies that improve the quality of life for everyone.
In the Dr. Stone series, Senku is a brilliant and resourceful guy, but there are some improvements that would benefit him and his team that he simply cannot create. This is because they are either too advanced for Stone Age technology, or require resources that are no longer available.
7 Smartphones
Before the petrification in the Dr. Stone series, smartphones were revolutionary. They could connect two people regardless of distance using wireless networks while serving as forms of entertainment and a massive collection of information using the internet. However, after humanity was set back to the Stone Age, all that was lost.
To make up for it, Senku created communication lines. However, his improvised Stone Age invention used improvised materials and could only work with a wire or as a one-way receiver. Furthermore, the quality of the audio received was poor. Despite his skills and improvisations, Senku ultimately could not create smartphones and had to settle for his primitive improvisations.
6 Robots
Every advanced civilization loves and adapts to the use of robots. With robots, life becomes easier as they help handle more menial tasks. If Senku could create them in the Stone Age, taking risks such as awakening the dangerous Tsukasa for his strength would have been unnecessary. Furthermore, the use of robots for manufacturing, mining, and transport would have been more practical given the lack of capable human hands.
Unfortunately, Senku could not create robots in the Stone Age as he lacked the necessary resources and technology. As creating robots required expertise in fields such as programming, electronics, and mechanics, the chances of their creation were minuscule at best.
5 Advanced Medical Devices
If life is cut short due to a lack of sufficient medical technology, then no civilization will survive for long. In the Stone Age in the Dr. Stone series, this was the case even after Senku awakened from his petrification. When either friend or foe was faced with a life-threatening injury, Senku could do nothing but petrify them to save their lives, and leave it up to the petrification to heal them before de-petrifying them.
If advanced medical devices like X-rays were available, the damage done could be appropriately assessed and treated without relying on the uncertainty of the healing properties of the petrification devices. Unfortunately, the appropriate medical expertise and intricate infrastructure needed are not found in the Stone Age, and even Senku could do nothing about it.
4 Artificial Organs
Artificial organs are big in the world today. If Senku was able to create artificial organs, he would have been able to revive people who had suffered irreversible damage to their internal organs, thereby expanding the pool of potential revivals while improving their health and quality of life.
However, Senku, with all his brilliance, cannot create them due to a lack of resources and sufficient advancement. So while artificial organs would have been incredibly helpful in the story, the technology available to Senku in the Stone Age world served as an understandable limiting factor as to why he could not create them.
3 High-Speed Trains
High-speed trains would have been a game-changer for the civilization-building efforts in the Dr. Stone series. It would have enabled the transportation of goods and people across long distances in a much shorter time, allowing them to expand their territories and access resources more easily. In a world where resources are scarce and time is a precious commodity, the ability to move people and goods quickly and safely would be invaluable.
Unfortunately, the materials required to build high-speed trains are not readily available to Senku and his crew. Moreover, the level of precision and expertise required to build such trains is beyond his team's capabilities.
2 Computers
Senku's quest to rebuild modern technology is no small task, and this includes the creation of computers. Creating computers would require a significant amount of resources, knowledge, and infrastructure. If Senku could create computers, it would be incredibly beneficial to him and his companions. Computers are capable of performing complex calculations and data analysis, as seen when Senku used computers before the petrification of humanity.
Despite Senku's exceptional intelligence and resourcefulness, he lacks access to the necessary materials and tools to build a computer. Moreover, the intricate design and craft skills of computer chips are beyond the capabilities of the personnel and technology available in the Stone Age.
1 Time Machine
Many brilliant scientists can not escape the urge to build a time machine that allows them to escape the confines of time. Even Senku is not exempt from this temptation. The benefits of building a time machine vary. However, Senku seeks to build one to travel back in time and prevent the apocalyptic petrification event that occurred several thousand years ago.
However, creating a time machine is an incredibly challenging task. It would require a deep understanding of theoretical physics, including concepts such as time dilation, wormholes, and the nature of spacetime itself. Furthermore, it would require access to advanced materials, which are beyond the technological capabilities of the Stone Age. Despite the obvious limitations of building a time machine in the Stone Age, Senku strives to do so at the end of the Dr. Stone manga series, never giving up on his dream of creating one.