- Reaction score
- 1,703
This brain-teaser has baffled physicists since 1883. Thanks to some innovative engineering, it finally makes sense.
“What would happen if a sprinkler went in reverse” is a question asked by only two kinds of people—bleary-eyed stoners and theoretical physicists. That’s because answering the question requires a mind-bending perspective that only advanced mathematics or (mostly) legalized drugs can provide.
First posed in 1883 by Austrian physicist Ernst Mach and popularized by Nobel laureate Richard Feynman, the “reverse sprinkler” question is relatively simple—if you put an s-shaped sprinkler in a tank of water, and the sprinkler sucked in water, what direction would it spin and why?
But this is where things get tricky. One camp adamantly suggests that the sucking force would pull the nozzle counter-clockwise, while others argue that inflowing water would smack the inside of the nozzle, forcing it clockwise.
“The answer is perfectly clear at first sight,” Feynman wrote in the 1985 autobiographical book, Surely You’re Joking, Mr. Feynman. “The trouble was, some guy would think it was perfectly clear one way, and another guy would think it was perfectly clear the other way.”
www.popularmechanics.com
“What would happen if a sprinkler went in reverse” is a question asked by only two kinds of people—bleary-eyed stoners and theoretical physicists. That’s because answering the question requires a mind-bending perspective that only advanced mathematics or (mostly) legalized drugs can provide.
First posed in 1883 by Austrian physicist Ernst Mach and popularized by Nobel laureate Richard Feynman, the “reverse sprinkler” question is relatively simple—if you put an s-shaped sprinkler in a tank of water, and the sprinkler sucked in water, what direction would it spin and why?
But this is where things get tricky. One camp adamantly suggests that the sucking force would pull the nozzle counter-clockwise, while others argue that inflowing water would smack the inside of the nozzle, forcing it clockwise.
“The answer is perfectly clear at first sight,” Feynman wrote in the 1985 autobiographical book, Surely You’re Joking, Mr. Feynman. “The trouble was, some guy would think it was perfectly clear one way, and another guy would think it was perfectly clear the other way.”
Scientists Have Solved the 141-Year-Old ‘Reverse Sprinkler’ Problem
This brain-teaser has baffled physicists since 1883. Thanks to some innovative engineering, it finally makes sense.
