After Time Travel, I Relied on the Laws of Physics to Save Another World.

The world tree holds up the sky and nourishes all things. After a long period of prosperity, the mana gradually dried up. The Nine Emperors of the Demon Clan ate away at the origin of the tree, and all the tribes fought fiercely for hundreds of years, and finally won a tragic victory at the cost of the dying World Tree. Thousands of years later, the giant tree still stands behind the mountains. Its branches and leaves are withered, but it has never fallen. The mana in the world is getting thinner and thinner, and new undercurrents are spreading under the snow. A young man from Earth died in a late night blizzard. When he opened his eyes again, he had become a baby named Elion Valenod in another world. He possesses scientific knowledge from his past life, a pair of young parents whose identities remain a mystery, a wooden house with a permanent fire burning in the fireplace, and a magical seed that can be repeatedly exhausted and regenerated. In this world, swordsmen wield fighting spirit to cut off magic, mages chant spells to build circuits, and powerful people raise slaves to serve as magic containers. Everyone believes that magic power is innate and cannot be increased. Only Elion knows that - he squeezes the magic power to exhaustion every day, and can get even a little more the next day. He began to use the laws of physics to dismantle the magic circle, and replaced lengthy spells with mental commands. But the shadow of the dead tree on the horizon is getting closer and closer, the defense line in the north of the village is collapsing, his father's sword has a scar that he doesn't dare to ask about, and there are plants he doesn't recognize hidden deep in his mother's garden. The blizzard waits for no one. He must learn to live with the knowledge of both worlds before the tree falls completely.