正如我们所知 彩虹的颜色
The rainbow, as we know it,
是红橙黄绿蓝紫
is Red, Orange, Yellow, Green, Blue, Violet.
六种颜色
ROYGBV.
我把靛省掉了 因为 说实话
I’m ignoring Indigo, because, let’s be honest,
靛色？
Indigo?
靛色确切是在哪里呢？
But where exactly is violet?
是在这里的最末端吗？
Is it at the end here?
深蓝色后面？
This dark blue?
这个浅蓝绿色是啥？
And what’s this brighter light blue-green?
青色吗？
Cyan, perhaps?
为什么我们不说彩虹是红橙黄绿青蓝
Why don’t we say the rainbow is Red Orange Yellow Green Cyan Blue?
这六种颜色呢？
ROYGCB
其实 其实我们说过 我们只是忘记了
Well, we actually do, and we’ve just forgotten.
当牛顿最初通过棱镜观察散射的彩虹光
When Isaac Newton originally observed a rainbow of light split
并为颜色标上
by a prism and made his labeling of the colors
“红橙黄绿蓝靛紫”时
as Red Orange Yellow Green Blue Indigo Violet,
他所说的“蓝”
the thing he called “blue” was indeed
其实是我们今天所指的蓝绿色 青色 或青蓝色
what we would now call blue-green, or teal or cyan
——让人思绪无穷的天空蓝
– reminiscent of the color of the blue sky.
我们今天所说的“蓝”在牛顿口中是“紫”
And what we now tend to call blue, Newton called violet
——就像红玫瑰 紫罗兰
– as in, roses are red, violets are blue.
也就是深蓝色
Dark blue.
他在“七色彩虹”中引入靛色
He only included indigo in his fundamental “seven colors of the rainbow”,
只是为了和西方的音乐音阶数量相配：
so that they would match the number of notes of the western musical scale:
哆来咪发嗦啦西 就是这样的
Do re mi fa so la ti… yeah.
正如我们所知 紫色和品红
Purple and magenta,and hot pink, as we know,
并不在棱镜折射出的彩虹里
don’t occur in the rainbow from a prism
因为它们只能通过红蓝光叠加产生
because they can only be made as a combination of red and blue light,
而这两者在彩虹的两端
and those are on opposite sides of the rainbow
——完全没机会重合
–nowhere near overlapping.
因此 棱镜折射出的彩虹中没有紫色或亮粉色
So there’s no purple or hot pink in the rainbow from a prism.
“红玫瑰 紫罗兰”中有蓝紫色
Violet is there in the “roses are red, violets are blue” sense,
但没有紫色
but purple is not.
那么 为什么天上的彩虹看上去有紫色呢？
So then why do rainbows in the sky often look like they have purple in them?
我认为 这可能是一种视错觉
I suspect sometimes it’s an optical illusion
小面积的深蓝被亮色环绕时看上去像是紫色
whereby nice deep blues in small amounts surrounded by a lighter color appear purplish to our eyes.
不过 有时紫色和粉色也确实存在
However, sometimes purple and pink really are there
因为彩虹实际上是“彩碟”
-because a rainbow is really a rain-disk:
日光中的每一种颜色反射在光边盘上
each color of sunlight reflects back in a bright-rimmed disc,
环大小各不相同
all of different sizes,
它们叠加在一起 形成有着彩色边缘的白盘子
which together add up to make a white disk with a colorful rim.
由于光是一种波
But because light is a wave,
雨滴产生的干涉使每个“盘子”出现多个光环
interference from the raindrops themselves actually gives each disk multiple rings
——我们所熟悉的外环只是最亮的一个
-the familiar outer ring is just the brightest.
其他的被称为“复环”
The others are called “supernumerary rings”
是复虹的源头
and are the source of supernumerary rainbows
雨滴越小 复虹越明显
-the smaller the raindrops, the stronger the supernumerary bows.
如果雨滴大小恰到好处
And if the drops are the right size,
第一个红色复环
the first red supernumerary ring
会叠加在主环的深蓝环上
can overlap significantly with the main dark blue ring,
红加蓝等于？
And what do red and blue give?
紫色!
Purple!
所以 正如俗话说
So as the saying goes,
红玫瑰 紫罗兰
roses are red, violets are blue,
彩虹中的紫色是一个复环
and purple in a rainbow is a supernumerary hue.