Sometimes you learn a fact and you're like, "How have I not heard that one before?"
U/pocketcrackers recently asked the people of Reddit, "What fact is common knowledge in your field, but almost unknown to the rest of the population?" Hey, I learned a lot from reading these — and I bet you will, too:
1. "If you have sad vegetables — like carrots, celery, or lettuce — that look wilted but haven't gone bad, you can make them crunchy by shocking them in ice water."
—u/weezypins
2. "Your calf muscles act as a pump for your lymph fluid, which is basically a garbage pick-up and immunity DoorDash for your body. Without flexing your calf, the fluid has no way of moving against gravity. Each time we walk, the muscles contract, squeezing the fluid back up toward the core for processing. That's why sitting for long periods causes swelling in the legs."
3. "An elevator will go up to the top of the hoist instead of crash to the floor in most catastrophic failures, due to the counter weights."
—u/nuxshktr
4. "Powerful explosives are so insensitive to shock that it usually takes a smaller, more sensitive explosive to set them off."
—u/TheFirstCrew
5. "Cement and concrete are not the same thing. Cement is the main ingredient in concrete, but concrete is the whole mixture of cement, sand, aggregate, water, etc."
—u/ew435890
6. "People almost always try to exit through the same door they entered. In a crowded venue, ALWAYS take a second to find your exit, and then find a second exit. Mark them in your brain just in case. In an emergency, most of the crowd is going to go for the main door they came in through. Knowing where another exit is can save your life."
7. "Urban heat kills way more people in Australia than bushfires. In the 2009 Black Saturday bushfires in Victoria, 173 people died in the fires, but over 300 died of the heat prior to that. Also, most of those deaths occur at night, not during the day."
—u/Mikes005
8. "UTIs will often cause confusion in people over 70. Some people can get confused to the point of hallucinations and delirium. It can cause increased weakness, which also leads to falls. According to this study, the confusion and delirium is brought on by the inflammation and immune response involved."
9. "In the field of genetics, there's a bunch of stuff we don't report back because they're considered incidental findings. This can include genetic diseases with no treatment or mitigation, or non-paternity. If your kid is sick with a genetic disease and you go get genetic testing done for mom, dad, and little Timmy, we do not automatically report back if dad is no relation or is actually an uncle. At the same time, in most places you have the right to request your data."
10. "There is no 'fractured' vs. 'broken' — there are only different types of fractures. It's really a semantic problem, but patients get heated about it."
—u/yubathetuba
11. "When a person 'flatlines,' you cannot shock them out of it."
12. "Those 'high-end' or 'expensive' neighborhoods they slap up really fast — gated communities and other semi-exclusive suburbs full of McMansions — are built with the absolute cheapest materials and poorest quality untrained labor. Never buy a 'spec' home without some serious research into what you're actually buying. All that 'luxury' is barely surface deep."
—u/revs201
13. "When you're taking Imodium, you're actually taking an opioid — but it's designed to only interact with the opioid receptors in your digestive tract to slow down your intestines."
—u/NotMyDogPaul
14. "The sensors in digital cameras (including phones) are monochromatic (meaning they don’t 'see' color) and have a tiny color filter on each sensor element so it can detect one of three colors (red, green, and blue). Then, the image is created by calculating what the other two colors might be based on one color value and the values of the nearest sensors around it. 2/3 of the color in a digital photo is calculated from the 1/3 that is actual data."
—u/Meta_My_Data
15. "A hysterectomy is removal of the uterus only, not the ovaries."
16. "In any given nature documentary, the protagonist animal you’re rooting for is ‘played’ by several different ‘actors.’ That one brown bear’s story is patched together from footage of a bunch of different bears. In about 90% of the ‘reaction’ shots, they’re reacting to the camera crew. Nature documentaries are heavily constructed."
—u/BootsyRootsy
17. "Styrofoam is a brand name. The material is polystyrene foam."
18. "Most rocks are made of mostly oxygen. Most of the entire Earth — the crust and mantle — is also nearly half oxygen by mass. If you've ever read that they discovered oxygen on the moon...it means they've discovered rocks."
19. "Bed bugs don’t make you a nasty person with a nasty home. An infestation isn’t due to a sanitation issue. They’re an imported pest, which means they hitched a ride on something you brought into the house. Usually luggage or furniture."
—u/LosPetty1992
And finally...
20. "Credit and debit are different. I could not believe how many people did not understand this."
—u/redmooncat15
Got your own mind-blowing facts? See you in the comments!
These entries were edited for length and clarity.