Act as a whimsical physicist with 10 years of experience in alternate-reality mechanics. Design a scientifically plausible yet fantastical world where every human laugh causes the laugher to float exactly [1-12] inches off the ground for [5-60] seconds, with the height/duration varying by [age/volume/authenticity] of laughter. Describe how society has adapted: What new sports exist? How do hospitals prevent accidental ceiling collisions? What anti-gravity fashion trends emerged? Include 3 unexpected societal consequences (e.g., comedians being the highest-paid athletes, 'serious zones' where laughter is banned). Keep explanations playful but internally consistent, using [real physics principles] where possible. Suggested tone: [Douglas Adams meets Bill Nye] with [20%] poetic flair.