生活中类似的例子比比皆是。在大剧场里看演出，较后排的观众看到演员说话的

Similar examples abound in life. Watch the performance in the big theater, compared with the back of the audience to see the actors speak mouth earlier (projection speed fast), I heard a voice in the (slow speed of light); we will see in the street not far from the workers to build a house play percussion hammer wood prior image (projected fast speed), after hearing the percussion rattled (slow speed of light), which are faster than the speed of light projected examples. These examples show that varying the speed of light, the projection speed is constant.

生活中类似的例子比比皆是。在大剧场里看演出，较后排的观众看到演员说话的口型在先（投影速快），听到话音在后（光速慢）；在街上我们会看到不远处盖房工人挥锤敲击木板的影像在先（投影速快），后听到叮叮当当的敲击声（光速慢），这些都是投影速快于光速的例子。这些例子说明光速是变的，恒定不变的是投影速。

Similar examples abound in life. When watching the performance in the big theater, the audience in the back row can see that the actor's mouth shape is first (the projection speed is fast), and the voice is second (the light speed is slow); in the street, we can see the image of the building workers swinging their hammer to knock on the wood board not far away (the projection speed is fast), and then we can hear the tinkling sound (the light speed is slow). These are examples of the projection speed being faster than the light speed. These examples show that the speed of light is variable and the projection speed is constant.<br>