太阳有多大?相当于30万个地球那么大。要测量出这个庞然大物的直径可不容易。别急,让我们利用下面的小孔成像知识,你就可以亲手测量太阳直径啦。光在空气中沿直线传播,这可以从物体的影子来证明,例如一束光照射到不透明的物体上,物体的后方就会呈现出影子。小孔成像就是光沿着直线传播的结果。用一个带有小孔的板子遮挡在屏幕与物体之间,屏幕上就会形成物体的倒像,我们把这样的现象叫小孔成像。这种现象反映了光沿直线传播的性质。如小孔成像 How big the sun? The equivalent of 300,000 Earth so big. To measure the size of this monster is not easy. Do not worry, let us use the following hole imaging knowledge, you can personally measure the diameter of the sun friends. Light travels straight in the air, as evidenced by the shadow of an object, such as a beam of light striking an opaque object that appears behind the object. Hole imaging is the result of light traveling along a straight line. With a board with a hole in the screen and objects obscured, the screen will form an inverted object, we call such a phenomenon hole imaging. This phenomenon reflects the nature of light traveling in a straight line. Such as pinhole imaging