Foreword The land, sun, and air that people in rural villages rely on have nurtured generation after generation. After several years of experience in rural design work, we found that middle-aged parents in rural China are working in big cities, far away from home. The elderly and children left behind have become the main people in rural life. In rural areas, children leave home for school during the day, and the elderly work at home because of physical limitations. At night, children will come home from school, have dinner and write homework. This is a daily day in the countryside, but it reflects the three conflicts in rural life; on the one hand, due to the age gap of residents and the non-overlap of daily lifetime, children and the elderly lack communication. On the other hand, the elderly generally stays in the house due to inconvenience in legs and feet, while traditional houses in rural areas usually have poor lighting conditions. Others are that children are usually out of school at night, the village is dark, and lack of lighting. In order to solve these three problems, we decided to use the daylight to solve those problems. Purpose; Our goal is to use the light tube to introduce the daylight into the farmer's home, which can improve the light environment of the elderly. At the same time, the light tube is used to store the rich daylight during the day, which can be converted to safe lighting for children on the road at night. Among them, we also hope that the elderly and children can have more communication when sharing this daylight. Light Tube design; The tube of body uses frosted glass, which can convert direct sunlight into diffuse reflection save into the tube. The two ends of the tube transmit sunlight through optical fibers, converting daylight from exterior into the interior. At the same time, we use resin panels with fluorite (CaF₂) milled in the seals at both ends of the tube and in the middle. During the day, the light is stored by the conduction of the optical fiber, which can emit light at night and leave the daytime natural light at night to illuminate. During the Day; The daytime light tube is on the wall, and the exterior daylight can enter the room through the tube, illuminating the living environment of the interior farmer's house and helping the elderly get sunshine. The frosted texture of the tube itself converts the direct light of natural light into diffuse reflection, while the optical fiber transmits the light inward, and the resin material absorbs enough sunlight during the conversion process. During the Night; At night, the light tube illuminates the wall and street. The resin material in the tube absorbs daylight during the day, and at night, it emits light to the exterior through the optical fiber. The tube illuminates the street from the wall at night, helping children light the road ahead on their way home, and has certain safety lighting. At the same time, you can add fun by mixing different colors of fluorite. Interact with light; Due to the lack of interaction between the elderly and children in life, the device is designed to be movable on the wall. At night, children can take the tube out of wall and use it as a moving light source to illuminate the way home. When the tube is taken away, the old owner knows that is the time out of school and can communicate with the children who come to get the light source. At the same time, when the children get the light guide home, they can also be placed at the door of their house as a sign of returning home. Neighborhoods can check this as a sign to take care of each other’s children home and maintain community safety. At this time, the light tube as a device can promote the communication between the elderly, children and neighbors, and use light to interact.