四大发明是关于中国科学技术史的一种观点，是指中国古代对世界具有很大影响的四种发明，是古代中华民族劳动人民的重要创造，一般是指造纸术、指南针、火药及印刷术。
The four great inventions is a point of view of "science and civilisation in China" refers to the Chinese ancient four inventions, has a great impact on the world of the ancient working people of the Chinese nation is important to create, generally refers to the papermaking, the compass, gunpowder, and printing.
指南针是用以判别方位的一种简单仪器。前身是司南。主要组成部分是一根装在轴上可以自由转动的磁针。磁针在地磁场作用下能保持在磁子午线的切线方向上。磁针的北极指向地理的北极，利用这一性能可以辨别方向。常用于航海、大地测量、旅行及军事等方面。指南针的N指北方，E指东方，W指西方，S指南方
A compass is a simple instrument for identifying bearings. The predecessor was si nan. The main component is a magnetic needle that can rotate freely on a shaft. The magnetic needle can be kept in the tangent direction of the magnetic meridian under the action of the earth's magnetic field. The North Pole of a magnetic needle points to the geographic North Pole, which can be used to identify directions. Often used in navigation, geodetic surveying, travel and military affairs. The compass N refers to the north, E to the east, W to the west, S guide.
造纸术是中国四大发明之一，人类文明史上的一项杰出的发明创造。中国是世界上最早养蚕织丝的国家。中国古代劳动人民以上等蚕茧抽丝织绸，剩下的恶茧、病茧等则用漂絮法制取丝绵。漂絮完毕，篾席上会遗留一些残絮。当漂絮的次数多了，篾席上的残絮便积成一层纤维薄片，经晾干之后剥离下来，可用于书写。这种漂絮的副产物数量不多，在古书上称它为赫蹏或方絮。这表明了中国造纸术的起源同丝絮有着渊源关系。
Papermaking is one of the four great inventions of China, an outstanding invention in the history of human civilization. China was the first country in the world to raise silk. China's ancient working people, such as silk, silk and silk, the rest of the cocoon, the cocoon, and so on. After the drift, the mat will leave some residue. When the number of floatation is much, the residue on the bamboo mat is formed into a layer of fibrous sheet, which can be removed after drying and can be used for writing. This flocculant floating there aren't many by-products, and call it h 蹏 on ancient book or side effect. This indicates that the origin of Chinese papermaking technique is related to the silk flocculation.
火药是中国古代炼丹家发明于隋唐时期，距今已有一千多年了。火药的研究开始于古代道家炼丹术，古人为求长生不老而炼制丹药，炼丹术的目的和动机都是超前的，但它的实验方法还是有可取之处，最后导致了火药的发明。
Gunpowder was invented in the sui and tang dynasties by the ancient Chinese alchemists. The research started in the ancient Taoist alchemy of gunpowder, the ancients for immortality and refining Dan medicine, the purpose of alchemy and motivation are advanced, but still have to recommend its experimental methods, finally led to the invention of gunpowder.
北宋科学家、政治家、道家学者沈括曾在《梦溪笔谈》中有一篇文章叫《活板》，其中详细介绍了活板印刷术的全过程，通俗易懂，非常详细。在他写于1088年的著作《梦溪笔谈》中，将此发明归于不知名的工匠毕升(990年-1051年)。随著烧结陶土字符的使用，沈括描述毕升制作字形、捡字排列、印刷、并在印刷后拆解留待后来使用。宋代虽然发明了活字印刷术，但是普遍使用的仍然是雕版印刷术。毕升曾尝试木制活字，但木制活字一直要到元朝(1271年–1368年)王祯(活跃于1290年至1333年)的木模才趋完善。王祯亦将文字按照音韵组合置于有小隔间的转轮排字盘以方便捡字。至于铜版活字要等到明朝(1368年-1644年)华燧(1439年至1513年)于1490年的印刷作品才趋完美
Northern song dynasty scientists, politicians, Taoist scholar shen kua in the MengXi writing "in an article called" trap ", including live board was introduced in detail the whole process of printing, easy to understand, very detailed. In his 1088 book, "dream brook," he attributed the invention to the unknown craftsman bi sheng (990 -1051). With the use of sinter clay characters, shen kuo describes the production of glyphs, collating, printing, and disassembling after printing to be used later. Although movable type was invented in the song dynasty, engraving was still widely used. He had tried wooden movables, but the wooden motifs had always been perfect until the yuan dynasty (1271 -- 1368) wang zhen (active in 1290 to 1333). Wang zhen also arranged the words according to the combination of rhyme and rhyme in the wheel of a small compartment for the convenience of picking up words. As for the copper version, it was not until the Ming dynasty (1368-1644) that the fusil (1439 to 1513) was printed in 1490.
新四大发明是指"高铁、支付宝、共享单车和网购"。2017年5月，来自"一带一路"沿线的20国青年评选出了中国的"新四大发明":高铁、支付宝、共享单车和网购。
The new four are "high-speed trains, alipay, bicycles and online shopping". In May 2017, the 20 countries along the "One Belt And One Road" selected China's "new four great inventions ": high-speed rail, alipay, sharing bicycles and online shopping.
