Korea is the first greenhouse in the world

 It's called "Dongwol Blossom Outsour Manwijah." "The flowers that bloomed in the winter months came from man-made flowers." It is a part of the king's whole school recorded in the 13th volume of the Annals of King Seongjong. On a cold day in January 1471, when Jang Won-seo, an organization for raising flowers used in the palace, offered Yeongsanhong, a type of azalea, to the king, the king said, "The flowers and fruits of vegetation receive the energy of heaven and earth, respectively, and I don't like them in time."     Other than liking spring flowers that bloomed in winter, it is a matter of King Seongjong's taste, but I can't help but wonder how he could bloom in winter in the past. Was there a greenhouse during the Joseon Dynasty? It is said that a German greenhouse, known as the world's first greenhouse, was built in 1619.….     However, a book called "Sangayalok" discovered in 2001 gave the answer. This book is a life science book written by Jeon Soon-ui, who served as a medical officer in the mid-15th century, and conveys a lot of information on life such as how to make alcohol, how to cook food, and how to store food along with agricultural technology at the time. Among them, there are three lines of records on greenhouse construction at the time in the "Dongjeolyangchae," that is, growing vegetables in winter." According to this, walls were built with mud and straw on three sides except the south, the floor was made of spheres, and cultivated soil of about 30 centimeters was laid on top of it, and the southern side inclined at 45° was covered with oiled Korean paper on the bars. Then, what was the performance of the Hanji greenhouse during the Joseon Dynasty? Greenhouses must have three conditions: heating, humidification, and mining. Modern greenhouses from Europe use a method of raising the air temperature in the greenhouse by blowing the heated air into the wind from the stove. This method has the disadvantage of putting a lot of stress on plants but not heating up cold ground. Therefore, in recent years, a "ground heating method" has been developed by installing heating pipes on the ground to increase the temperature of the soil affected by the roots. However, ondol was already installed in the greenhouse during the Joseon Dynasty, so the temperature of the soil could be maintained at 25℃. Ondol was heated for two hours in the morning and evening, and at this time, a cauldron was placed on the furnace and water was boiled, allowing water vapor to flow into the greenhouse. This allowed the room temperature and humidity to be increased. Above all, "Hanji" played a major role in allowing Joseon to have an excellent greenhouse at least 170 years ahead of Europe. In the days when there was no pan glass, Joseon engineers used perilla oil on Korean paper used as book paper and window paper as a mining window. In glass or vinyl greenhouses, dew forms at dawn depending on the temperature difference between indoor and outdoor. Cold dew not only lowers the indoor temperature by blocking the morning sun and interferes with the photosynthesis of plants, but also falls directly on the crops, causing great harm. However, the Hanji greenhouse does not have dew. Perilla oil fills the empty space between paper fibers, making Korean paper waterproof. However, large liquid particles such as raindrops cannot enter the greenhouse through the space between paper fibers due to oil, but because perilla oil does not completely fill the space between paper fibers, small water vapor particles are released out through hanji. The oiled hanji may be said to be the origin of Gore-Tex. Also, to be able to function as a greenhouse, light transmittance must be good, but can hanji transmit light? Korean paper is opaque, but oil-filled Korean paper becomes translucent as it becomes taut. The light refractive index of the paper fibers that make up Korean paper and the air filling the space is different. When two substances with different refractive indices are mixed together, light is scattered and reflected. However, the refractive index of oil is similar to that of paper fibers, so the amount of light scattered is reduced, so the transmittance of light is increased. In Hanji Greenhouse, vegetables could be harvested for three to four weeks after sowing, and summer flowers could be supplied to the palace even in the middle of winter. Experiments have revealed that greenhouses in the 15th century of the Joseon Dynasty, which made a mining window with Korean paper and controlled temperature and humidity using ondol, were more scientific than modern greenhouses. But what's even more surprising is that the technology has slipped away without being passed on to posterity. (Science Fragrance: Lee Jung-mo, Scientific Columnist) Guagel Bulferm. From what I can tell, it is not our ancestors that the Korean history is poor, but our responsibility from our great-grandfather to now. History is the mirror of the present, not the past.