Wild Insides
#5How things work
Why Shopping Carts Lock Up At The Parking Lot Edge
Some shopping carts have a hidden brake in one wheel.
Short. Strange. True.The real science
how it works · fire sprinkler · sprinkler bulb · fire safety · glass bulb sprinkler · movie myths
The real science
That little red glass bulb in a ceiling sprinkler works as a heat fuse. When a fire heats it, the liquid inside expands until the glass shatters, which lets the water out. Each head reacts to its own heat, so the whole building does not get soaked like in the movies. If you ever see smoke, get out and call emergency services.
Don’t try anything shown in this video. This is general science, not medical advice — if you’re worried, contact a professional.
Follow the facts
- IAFSS: Liquid Expansion in Glass Sprinkler Bulbs
- Fire Technology: The Response Time of Different Sprinkler Glass Bulbs
- Fire Protection Association: How do fire sprinklers work?
Ask about this science
Curious about something in “Why Only One Sprinkler Turns On In A Fire”? Our AI-powered helper answers using only this page’s write-up and sources.
AI answers can be wrong; check the sources. Not medical advice.
Our illustrations simplify anatomy and scale. Educational content only; not medical advice.
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#5
#3How things work
Why A Snapped Elevator Cable Won't Drop You
Almost everyone has wondered what happens if an elevator's cable snaps.
Short. Strange. True.The real science
#2How things work
How Pill Bottle Caps Outsmart Most Toddlers
Child-resistant medicine caps hide a two-part lock that only opens when you push down and turn at the same time.
Short. Strange. True.The real science