科技史小記

• Ref.:太極是由觀測日影而來的？ « Heresy's Space
  
  很有趣的論點。不過我很佩服 Heresy 花這麼多時間去做這個動畫。
  
• Ref.:Here is why vim uses the hjkl keys as arrow keys - good coders code, great reuse
  
  
  所有的設計都是有歷史因素的，就像 QWERTY鍵盤是從打字機衍生過來一樣，軟體的 Hot Key 也是有原因的。
  
• Who invented the call stack? - Quora
  
  據說 Stack 的概念是 A. Turing 發明，這個詞則是 E.W. Dijkstra 創造的。
  
  
• Ref.: 11011110: An almost-forgotten combinatorist: Heinrich August Rothe
  
  • The first definition of the inverse of a permutation
  • A proof that the number of inversions of a permutation (the concept that Muir called "ill-advised and purposeless") is the same as for its inverse
  • A proof that the determinant of a matrix is the same as for its transpose
  • A diagram (the Rothe diagram) still used for visualization of permutations and inversions
  • The first definition of a self-inverse permutation
  • A simple recurrence formula for the number of self-inverse permutations
  很多人喜歡說自己多有創意，其實是他們對歷史所知太過貧乏，我們還是該謙卑一點。