Where does trash go? This question came from a reader submission (thanks Zuzu!). Has a curious question stumped you lately? Feel free to submit your own question here: Submit your question 📓 The short answer Trash typically goes through a multi-phase journey: it's first collected and sorted, then processed at various facilities depending on its type. Most waste ends up in landfills, but some is recycled, composted, incinerated for energy, or even exported. Last week, I asked how you'd feel if...
12 days ago • 9 min read
How does Today You Should Know work? This question came from no one in particular, but seeing as this is the 150th edition of the newsletter, I thought I'd do a behind-the-scenes. I could not come up with all these newsletter topics on my own, so please keep the curious questions coming! Submit your question 📓 The short answer Fueled by reader-submitted questions, I work on Today You Should Know nearly every morning — researching, creating custom diagrams, writing, editing, and managing the...
19 days ago • 9 min read
How do controlled burns work? This question came from a reader submission (thanks Mom!). Has a curious question stumped you lately? Feel free to submit your own question here: Submit your question 📓 The short answer Controlled burns, or prescribed fires, are intentionally set by professionals to reduce wildfire risk and support ecosystem health. Burn bosses must get a rigorous burn plan approved and execute with carefully designed ignition methods and timing to control fire behavior. 📚 The...
26 days ago • 6 min read
Why do we have leap years? This question came from a reader submission (thanks Shi So!). Has a curious question stumped you lately? Feel free to submit your own question here: Submit your question 📓 The short answer Leap years exist because a full orbit around the Sun takes 365.242189 days, so we add extra days to keep our calendar aligned with the seasons. The Gregorian calendar uses specific leap year rules to stay closely synced with the solar year, skipping three leap years every 400...
about 1 month ago • 5 min read
What causes dark circles under your eyes? This question came from a reader submission (thanks Aastha!). Has a curious question stumped you lately? Feel free to submit your own question here: Submit your question 📓 The short answer Dark circles under the eyes can result from true hyperpigmentation—caused by excess melanin, iron deposits, skin thickening, or visible blood vessels—or from shadowing effects due to changes in under-eye volume like hollowness or puffiness. 📚 The long answer Perhaps...
about 1 month ago • 7 min read
What made old Nokia phones nearly indestructible? This question came from a reader submission (thanks Jana!). Has a curious question stumped you lately? Feel free to submit your own question here: Submit your question 📓 The short answer The Nokia 3310 was nearly indestructible thanks to its rugged double-shell plastic design, compact build, recessed screen, non-glued components, single Printed Circuit Board, and a company-wide emphasis on durability and reliability. 📚 The long answer As...
about 2 months ago • 5 min read
Why are teenagers so impulsive? This question came from a reader submission (thanks Linux!). Has a curious question stumped you lately? Feel free to submit your own question here: Submit your question 📓 The short answer Teenagers are more impulsive because their brains are still developing faster access to the parts responsible for self-control, while emotion and reward systems are already firing on all cylinders. Hormone spikes, limited life experience, and peer pressure also contribute to...
about 2 months ago • 6 min read
Can you cook pasta without boiling water? This question came from a reader submission (thanks Marc!). Has a curious question stumped you lately? Feel free to submit your own question here: Submit your question 📓 The short answer Yes, the key chemical reactions that cook pasta happen at around 180°F (82°C), below the boiling point of water (212°F (100°C)). But cooking pasta at this lower temperature will require you to cook for a longer time. 📚 The long answer On the package of your favorite...
2 months ago • 6 min read
Why does oversleeping make you tired? This question came from a reader submission (thanks Rodrigo!). Has a curious question stumped you lately? Feel free to submit your own question here: Submit your question 📓 The short answer Oversleeping can make you feel more tired because it throws off your internal clock. You might wake up during a deep sleep stage, miss your body’s natural cortisol boost that helps you feel alert, and wake up dehydrated – all of which can cause you to feel tired. 📚 The...
2 months ago • 5 min read