我们置身于银河系的太阳系之中，就好比一粒尘埃，不知寰宇之大小。敢问银河什么样?一般人都知道银河像是两个扣在一起的盘子，侧面很薄，正面是个盘状的漩涡。可是你有没有想过，我们身在银河中，又是如何知道银河...
mystery finally we are in the Milky Way Department of the solar system, is like a grain of dust, I do not know the size of the world. Ask what the Milky Way? Generally known as the Milky Way two buckle together side dishes, very thin, positive is a disc shaped vortex. But have you ever thought that we are in the Milky way, and how do we know that the Milky way...
