At the End of Science, There's Boiling Water

Li Sui, a modern PhD in materials science and engineering, accidentally transmigrates to Yuzhou, a fictional ancient world ravaged by war and poverty. Faced with a brutal reality of corpses strewn across the land and primitive technology, he is astonished to discover that the underlying principles behind many of the core technologies that propelled human civilization forward are remarkably simple. Many of them revolve around boiling water and the energy conversions it makes possible. Armed with scientific thinking and engineering skills far beyond his time, Li Sui resolves to start from scratch, using boiling water as his starting point to develop new technologies, improve people's lives, and end the age of chaos.