光速運動時時間變慢的原因

因為當我們在 3+1 (x,y,z,time)維移動時, 我們像是在一個空間(y-axis) vs 時間

(x-axis) 的圖表中移動。


假設我們在3+1維以一個單位"前進",

當你在空間(y-axis)完全靜止時, 那一單位便完全地向時間(x-axis) 前進, 那代
表我們的時間流速沒有減慢。

當你在空間(y-axis)移動[不是光速]時, 那一單位便不會完全地向時間(x-axis) 前進,那單位也在空間軸移動,所以相對地那單位在時間軸的長度縮短了,那代表我們的時間流速被減慢了。

當你在空間(y-axis)完全移動時[光速], 那一單位便完全地向空間(y-axis) 前進, 那單位完全地在空間軸移動,所以相對地那單位在時間軸完全沒有長度, 等於時間完全
停止。

當你移動得被光速更快時, 那單位還會指向時間軸的負值,也就是為甚麼人們常說
被光速更快會時間倒流。 (像穿越戲一樣)

其實沒有那副圖很難明白, 看了這段片(http://www.youtube.com/watch?v=G-R8LGy-OVs)會較容易明白。
開頭是光速不變原理, 然後便是了!!!





加上有條公式: 勞侖茲因子(那個符號不知點打)=1/ square root [1-(v^2/c^2)]

勞侖茲因子是代表時間的膨脹程度。 假設v=0, [勞侖茲因子=1]時間沒有膨脹

(時間會流動),但當v=c時, [勞侖茲因子=∞]便代表時間完全膨脹(時間不流動)。

The main reason is the assumption that the speed of light is the same irrespective to the motion of the observer. This is one of the basic assumptions used by Einstein in formulating the Special Theory of Relativity (特殊相對論).

Just as a simple illustration. Suppose an observer on earth watch the motion of a light photon, which travels a distance L in one second. Using the relation: speed = distance/time, we have c = L/1 (where c is the speed of light as observed by the observer on earth),
i.e. c = L -------- (1)

Now, another observer in a spaceship travels at, say, a speed of half the speed of light. Suppose the spaceship starts together with the light photon, then after 1 second (time as measured on earth), the photon travels a distance of L, whereas the spaceship travels a distance of L/2. That is, the observer in the spaceship sees the photon at a disatnce of L/2 ahead ot him.

Hence, using equation (1),
time t = distance/speed = (L/2)/c = (L/2)/(L) = 1/2
Thus, the same event that takes 1 s to the observer on earth becomes to last 1/2 second to the onserver in the spaceship. The time in the spaceship thus appears to run slower.

Be aware that this is only a qualitative illustration. Do not regard it as a formal proof of the theory.