茫茫宇宙无边无垠，耿耿星辰变化万千。人们自然要问：宇宙到底有多大？它的结构和运动如何？这是人类至今未揭开的谜。在16～18世纪全球大探险的年代，探险家们深入辽阔的海洋和未知的新大陆，逐渐知道了关于海洋和陆地的更多知识，最终绘制出了详尽准确的世界地图，大大加快 The universe is boundless and the stars are changing. People naturally have to ask: How large is the universe? How is its structure and movement? This is a mystery that has not yet been revealed by humans. In the era of global exploration in the 16th and 18th centuries, explorers went deep into the vast oceans and the unknown New World. They gradually learned more about the ocean and the land, and finally plotted detailed and accurate maps of the world.