Breath. Air is light, but even Stig Severinsen, the world record holder can only hold his breath for 22 minutes. The world’s strongest man can’t beat that, but you can have the pleasure of telling him to his face.
Braille was based on a tactile military code called night writing, developed by Charles Barbier in response to Napoleon’s demand for a means for soldiers to communicate silently at night and without light. In Barbier’s system, sets of 12 embossed dots encoded 36 different sounds. It proved to be too difficult for soldiers to recognize by touch and was rejected by the military.
Think of the six-letter name of a European capital city whose starting letter falls in the last half dozen letters of the alphabet and whose last letter is a vowel.
Now think of a three-letter words that means “permit”.
Last, combine all nine letters from the two words above. Rearrange the letters to form a word that you might call someone you like.
Look in the mirror, then at the wall and back at the mirror to see what you saw. Use the saw to cut the table in half and join the two halves to make a whole. Put the “hole” on the wall and climb out.
I know, it’s lame. I like to have brain teasers that you can realistically guess, but this one’s so popular, I feel an obligation to include it.