In today's comments, we watched a coin fly over a cup, debated the merits and drawbacks of 3-D screenings... and came up with some invaluable additions to the time-traveler's handbook.

Responding to this post on 10 silly tropes of sci-fi time travel, commenter twophrasebark throws in a few more unusual features of sci-fi time travel to the list:

11) People will speak modern English whenever you travel back into the past.

12) The Earth is traveling around the Sun at 67,000 miles/hour but whatever about your geographical location from when you left to when you get there

13) Time travelers always travel to the point where the most exciting plot developments happen, but rarely to the time that makes the most sense. (Example: Picard and Kirk can return anywhere in Generations, but choose to confront Soran when he is about to launch his super weapon. But Picard could have left Kirk to enjoy paradise forever and just returned to the moment he met Soran and decked him. The End.)

Heed these instructions, time travelers.

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