評論
打印
The Green Door
綠色的門
Don: Here's a simple demonstration you can do with cool implications. Find a large object that is brightly colored—let's make it a green door.
告訴你一個很簡單的論證：通過它你可以得出很酷的答案。找到一個大的顏色鮮艷的物件——將其視作一扇綠色的門。
Stand with that door to your side but don't look directly at it; you want it to be in your peripheral vision. Now, without shifting your gaze, examine the door in the edge of your field of vision. What color is it? Answer? It's still green.
靠著那扇門站定，但是不要直視它，只是把它納入你的周邊視野即可。現在，不改變凝視的方向，從你視野的最邊緣仔細看看那扇門。它是什么顏色的？答案是什么？那扇門依然是綠色的。
Yael: It's still green? What kind of experiment is that? I thought you are going to say something happens to the color.
還是綠色？這是個什么實驗啊？我猜你接下來應該會講講，那扇門的顏色究竟發生了什么神奇的事情。
D: That's exact right! The color stays green, which means something has happened—because nothing in your peripheral vision should have any color at all.
當然！門保持綠色就意味著發生了什么改變——因為在周邊視野范圍內事沒有什么顏色的。
Y: Nothing in your peripheral vision should have any color? Why not?
周邊視野范圍內是沒有顏色？為什么？
D: Because color is what we perceive when light of a particular frequency meets cones–special cells in your retina. But the light being reflected off the door is only landing on the outside edge of your retina. And there are almost no cones on the edges. Everything we see roughly seventy-five degrees away from the point we're fixed on should be black and white.
因為，當特定波長的光線作用于視錐細胞（視網膜中的一種特殊的細胞）時我們所接收到的便是顏色。但是，從門上發射出來的光線僅能到達視網膜的外緣，在視網膜的外緣幾乎沒有視錐細胞。從我們所凝視的方向斜75度角所看到的所有東西都只能是黑白的。
Y: That's fascinating! But why is the door still green?
太神奇了！可為什么門還是綠色的呢？
D: Presumably the door remains green because vision isn't a simple matter of retinal cells. All the data your eyes send is interpreted by the brain. Your brain knows that the door is green, so it supplies information that isn't really there to keep the image stable.
門一直保持綠色大概是因為我們的視覺并不僅僅是視網膜細胞所能控制的吧。由眼睛傳送的所有信息都是經過大腦編譯的。大腦所給出的信息是：門是綠色的。因而，大腦傳送出了并未遵循圖像的信息。
This is just one of the many ways your brain saves time and energy by making reasonably safe assumptions about the world around you.
為節省時間與精力，大腦對你周圍的世界作出合理、安全的假設——而這僅僅是眾多省時省力的方法之一。
