Everyday Science Debunked: The Truth About Rust, Lightning, and Shaving
Debunking 5 stubborn everyday science myths: does rust cause tetanus, does lightning never strike twice, and does hair grow back thicker?
Human beings are pattern-seeking creatures. When two events happen near each other in time, our brains assume a causal connection—even when the underlying biology and physics prove otherwise.
From old wives' tales whispered by well-meaning parents to misconceptions taught in elementary school classrooms, here is the real science debunking five classic everyday myths.
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| 5 EVERYDAY SCIENCE MYTHS BUSTED |
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| MYTH 1: Rust causes tetanus when you step on a nail |
| MYTH 2: Lightning never strikes the same place twice |
| MYTH 3: Shaving causes hair to grow back thicker and darker |
| MYTH 4: Microwaves cook food from the inside out |
| MYTH 5: Chewing gum stays in your stomach for 7 years |
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Myth 1: Rust Causes Tetanus
The Myth: If you step on a rusty nail or cut yourself on rusty metal, the iron oxide rust infects your blood with tetanus.
The Reality: Rust (iron oxide, ) is completely chemically harmless in regard to tetanus.
Tetanus is caused by an anaerobic bacterium called Clostridium tetani:
THE REAL TETANUS INFECTION PATHWAY
Anaerobic Soil / Manure (Thrives in zero-oxygen environments)
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Bacterium Clostridium tetani forms durable endospores
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Deep puncture wound (Pushed into flesh where oxygen is absent)
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Bacterium germinates & releases Tetanospasmin (neurotoxin)
Why do people associate rust with tetanus? Because rusty nails are usually found outdoors in dirt, soil, and agricultural manure—the exact habitat where Clostridium tetani thrives!
A squeaky-clean, sterile rusty nail in a laboratory will never cause tetanus; an un-rusty splinter from a dirty garden compost bin easily can.
Myth 2: Lightning Never Strikes the Same Place Twice
The Myth: If lightning strikes a spot near you during a storm, that spot is safe because lightning never hits the exact same location twice.
The Reality: Lightning actively prefers striking the same location repeatedly!
THE EMPIRE STATE BUILDING REALITY CHECK
Struck by lightning approximately 25 TO 100 TIMES EVERY SINGLE YEAR!
Lightning is an electrostatic discharge seeking the path of least electrical resistance to ground: Tall, conductive structures (skyscrapers, radio towers, copper church spires) provide a direct ionized channel for stepped leaders. Once a channel ionizes, residual plasma lowers atmospheric resistance, making repeated strikes within milliseconds—and across future storms—statistically inevitable.
Myth 3: Shaving Makes Hair Grow Back Thicker and Darker
The Myth: If you shave your facial hair, arms, or legs, the cut hair follicles respond by growing back coarser, thicker, and darker.
The Reality: Shaving has zero biological impact on the hair follicle beneath the skin.
CROSS-SECTION: NATURAL vs SHAVED HAIR
Natural Uncut Hair:
[ Base ] ===============================> [ Tapered Soft Point ]
Shaved Hair:
[ Base ] ===============================| (Blunt, Flat Edge)
- Natural hair tapers down to a soft, rounded, microscopic tip.
- When a razor cuts hair flush with the skin surface, it cuts across the thickest part of the hair shaft, leaving a flat, blunt edge.
When that blunt edge emerges a millimeter above the skin, it feels rougher and coarse to the touch. Furthermore, newly emerged hair has not yet been bleached by ultraviolet sunlight, making it appear darker. Clinical dermatology trials established as early as 1928 that shaving alters neither growth rate nor shaft diameter.
Rigorous science is about stripping away visual illusions and understanding the true physical mechanisms running our lives.