What If You Could Turn Invisible?

This slice of pizza is floating down the corridor. Because you're holding it. And you're invisible. Hold your breath and you vanish. Breathe, and you're back. Your record is two minutes, and only your best friend knows it isn't editing. Then, at eleven at night, a video from her phone: a dark warehouse, the boat leaves at six, bring the ghost. You've done this a thousand times. But nobody tells you the one thing about being invisible that changes everything. 0:00 The ghost of the corridor 0:43 The video 0:58 Seven hours 1:17 Invisible means blind 1:39 Clicks in the dark 2:04 The dog 2:27 The heat camera 2:54 Behind the glass 3:25 The deal 4:00 Her voice in your ear 5:05 The choice 5:31 The boat 6:26 The last breath 7:00 The dock 7:32 The door Would you save the friend who sold you? Tell us in the comments. If you'd go back for Nico, leave a like. We'll find out who's at the door. *Real science in this video* To see, your eye has to absorb light. An eye that light passes straight through can't see: standard optics. Cloaking research meets the same trade-off: Alù & Engheta (2009), "Cloaking a Sensor", Physical Review Letters 102, 233901. Some blind people find their way with tongue clicks, and the echoes are processed in the brain's visual areas: Thaler, Arnott & Goodale (2011), PLoS ONE 6, e20162. Blind and sighted adults learned it in 10 weeks: Norman, Dodsworth, Foresteire & Thaler (2021), PLoS ONE 16, e0252330. Heat (thermal) cameras see body heat, but ordinary glass and water block the long-wave infrared they see. A plain tongue click is made by the tongue, not the lungs (a click consonant's airstream). Sound travels about four times faster in water than in air. *Breath-holding under water can make you black out with no warning. Never do it alone.* CDC (2015), "Hazardous Breath-Holding Behaviors", MMWR 64(19). The story is fiction. Never practise breath-holding in water, and never alone. *Sounds* "Heartbeat Slow Tempo" by CTCollab (https://freesound.org/people/CTCollab..., CC BY 3.0 · "marker cap open 2" by Geoff-Bremner-Audio (https://freesound.org/people/Geoff-Br..., CC BY 4.0 · waves by klankbeeld (https://freesound.org/s/470757/), CC BY 4.0. Other sounds CC0 (Freesound) or the Mixkit licence. Music: Mixkit ("Okay", "Dark Shadows", "Fright Night", "Selpan", "Ode to Loneliness", "The Long Road", "Echoes", "Piano Reflections", "Staring at the Night Sky" and others), Mixkit Stock Music Free License.