I started writing a new draft titled "Time and Tesseracts" and would love to get your comments, whether I receive them before or after I publish the essay on my blog (late on the 16th or early on the 17th). Sorry for the many rough spots near the end, which I plan to work on over the next couple of days. Even after the 17th I'm likely to continue to tinker with the piece, and feedback will be gratefully acknowledged. (I'm aware that the footnote-links don't work, but there are probably lots of other glitches I'm unaware of.) Please leave your feedback here: https://mathenchant.wordpress.com?p=2303&shareadraft=5afa4b14f3cc0 but be aware that the feedback-link is a "party line"; if I receive an unsigned comment there, all I'll know is that it's from some math-fun subscriber. (Which may be your intention. But if you have a comment I want to act upon, I may have some follow-up questions for you, such as "Is the following rewrite less terrible?", which I won't be able to ask you if I don't know who you are!) Title: Time and Tesseracts Beginning: "The fourth dimension became a thing you talked about, without knowing what it meant." --- Marcel Duchamp 16th-century scholar Gerolamo Cardano1 thought the fourth dimension was contrary to Nature. 17th-century thinker John Wallis2 thought the very idea of it was monstrous. And now 21st century virt... Read more: https://mathenchant.wordpress.com?p=2303&shareadraft= 5afa4b14f3cc0 Thanks, jamespropp