Recommend 3blue1brown

22 sec read

When I was in high school and saw the following equation, my mind was blown!
$$1+\frac{1}{4}+\frac{1}{9}+\frac{1}{16}+…=\frac{\pi^2}{6}$$

Why is Pi here? Isn’t it supposed to show up only in circle related problem? But the left-hand has nothing to do with circle. And it’s Pi squared!

Even today I still do not have an intuitive understanding why the above equation is true, until I watched a visual explanation from 3blue1brown. This video provide an elegant and visual proof of the equation. Go ahead and watch it:

The link is:
https://www.youtube.com/channel/UCYO_jab_esuFRV4b17AJtAw/featured

请跟我来

今天无意中看了崔永元和水均益的女儿水亦诗唱的《请跟我来》,很感动。已经记不清什么时候第一次听这首歌,但是这简单的旋律、崔永元浑厚和水亦诗纯洁的嗓音,一下子把我带到青春的过去。我感觉心好像融化一般,眼泪也不由地流了下来。 点击下面Youtube的链接可以欣赏他们的演唱。后面是歌词。朴素的歌词,却总有打动人心的力量。 请跟我来 作曲:梁弘志 编曲:钟兴民 填词:梁弘志 主唱:苏芮–虞戡平 歌词: 我踩着不变的步伐 是为了配合你到来 在慌张迟疑的时候 请跟我来 我带着梦幻的期待 是无法按捺的情怀 在你不注意的时候 请跟我来 别说什么 那是你无法预知的世界 别说你不用说 你的眼睛已经告诉了我 当春雨飘呀飘的飘在 你滴也滴不完的发梢 戴着你的水晶珠链 请跟我来
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