Why do mirrors flip left and right but not up and down?

This is a question that people have been puzzling over ever since we discovered mirrors. A really simple comprehensive answer is surprisingly hard to pin down. Find out whether the Mathologer's answer ticks all the boxes.

English subtitles contributes by Anthony Whittington. Thank you very much Anthony!

Enjoy :)

• #education
• #mathologer
• #mathematics
• #math
• #maths
• #magic
• #ambigrams
• #mirror
• #paradox
• #trick_mirror
• #why_do_mirrors_exchange_left_and_right
• #why_do_mirrors_flip_left_and_right
• #mirrror
• #looking_glass