I knew vacuum tubes did exist. Like I knew dinosaurs once populated the earth. I remember my seventh grade teacher doing the best he could to explain to us evolution and dinosaurs. However, regarding vacuum tubes, nobody took the time to explain to me the part they played in the electronics evolution.
It was a big surprise to see them in 6.002x. In a week six's tutorial there was an example with a vacuum triode. I must confess I did not understand its purpose. Gerald Sussman explained that they are used in special applications. I thought those special applications do not play a need on our electrical engineerings. However I though it could be interesting to show students how a vacuum tube works.
Regarding this effort, I cannot help to quote Lawrence Summers words: "Part of universities's function is to keep alive man's greatest creations, passing them from generation to generation." Vacuum tube was one of electrical engineering greatest achievements in the past century. Ignoring Vacuum tube it is to ignore one of engineering's greatest creations.