Why Didn't They Just Live by the Waterfall? A Quiet Place Told You.

If a waterfall can swallow a scream, why on earth do the Abbotts live on a farm? A Quiet Place answers it thirty-five minutes in, on a riverbank, before it even shows you the waterfall. Another day in the yard!!!! Lee gives Marcus the rule by the river: small sounds are safe, big sounds aren't, "unless there's another sound nearby that's louder." Three minutes later the film shows you exactly what "nearby" means. This one checks that rule against real physics (the inverse square law, a waterfall measured by two physicists from the University of Oslo, how loud a shout really is), against NIOSH's hearing limits, and against a frog in China that calls in ultrasound to be heard over the water. Then Part II and Day One give the water answer the first film only half had: an island, a moat, and an army that worked out on day one that the creatures can't swim. And for @welshdave5263, who asked under our Independence Day video how the military got overrun before anyone found the frequency: we said 100%, so here it is. CHAPTERS 0:00 Intro 1:17 The rule by the river 2:55 Three minutes later 5:00 The roar works both ways 6:52 What Lee built instead 8:10 The island 9:33 How did the army lose? 11:49 Nearby Narrated by: Me :) Thank you @welshdave5263 for the question, and @Loreweavver for the underground theory under our Graboid video. SOURCES - A Quiet Place (2018), dir. John Krasinski, screenplay by Bryan Woods, Scott Beck and John Krasinski (Paramount Pictures, Platinum Dunes). Every film line quoted is from the film itself; signed lines are subtitled from the film's own English subtitles. - A Quiet Place Part II (2020), dir. John Krasinski (Paramount Pictures). - A Quiet Place: Day One (2024), dir. Michael Sarnoski (Paramount Pictures). - Vistnes AI, Bergli J (2021). Hanbury Brown and Twiss effect demonstrated for sound waves from a waterfall; an experimental, numerical and analytical study. University of Oslo. arXiv:2106.08137 (waterfall 17 m wide, about 60 dB(A) at about 78 m). - HyperPhysics, Georgia State University: Inverse Square Law for Sound ("doubling the distance drops the intensity by about 6 dB"). - Pearsons KS, Bennett RL, Fidell S (1977). Speech Levels in Various Noise Environments. U.S. EPA, EPA-600/1-77-025 (shouted speech, male talkers: 89 dBA), via Phonak Audiology Blog, "How loud is loud speech and can hearing aids process a shout?". - NIOSH / CDC, Noise-Induced Hearing Loss: recommended exposure limit of 85 dBA averaged over an eight-hour workday, 3 dB exchange rate. - Feng AS, Narins PM, Xu CH, Lin WY, Yu ZL, Qiu Q, Xu ZM, Shen JX (2006). Ultrasonic communication in frogs. Nature 440:333-336. NIH/NIDCD news release, March 2006 ("Scientists Discover Reason Behind Ear Canal in Chinese Frog: Ultrasonic Communication"). - Headquarters, Department of the Army (1987). FM 21-60 Visual Signals (public domain). - Millicent Simmonds: Wikipedia; Universal Pictures International Netherlands featurette (2018). - Cave of the Winds, Niagara Falls State Park (Bridal Veil Falls). FOOTAGE Film clips are used under fair use for commentary and criticism: A Quiet Place (2018), A Quiet Place Part II (2020), A Quiet Place: Day One (2024). Clips and footage via: Paramount Pictures (A Quiet Place: Day One trailers), Universal Pictures International Netherlands (Millicent Simmonds featurette), dferg100 (Cave of the Winds, Niagara Falls 4K), Andy's Awesome Adventures (Dettifoss), Science in a Van (decibel meter), Cook Children's Health Care System (cochlear implant activation), Campbell Aviation, 32TFS Aviation, Onetz. Stills: Wikimedia Commons (Bobby Darin, 1959, public domain; Odorrana tormota photo by Zhuo Chen, Junqiong Chen, Yao Liu, Jie Zhang, CC BY 4.0).