If you’re like the folks at TopatoCo, you live in constant fear of slipping into a wormhole and getting spit out in the 13th century — with no useful knowledge.
Unfortunately, their time traveler essentials poster strikes me as less than ideal for hanging in your time machine.
Am I supposed to need a poster to remind me that an airplane wing is an airfoil? If so, am I then supposed to know everything else needed for building a heavier-than-air craft from primitive materials?
And who makes a time-travel cheat sheet without the formula for gunpowder? Seriously. Amateurs. Oh, and good luck asking the natives for some potassium nitrate.
I suggest something more than a poster — The Best Time Travel Stories of the 20th Century and Caveman Chemistry.