Why does nails on a chalkboard give you chills? This question came from a reader submission (thanks Casey!). Has a curious question stumped you lately? Feel free to submit your own question here: Submit your question π The short answer Nails on a chalkboard sound awful because our ears naturally amplify those frequencies. It's theorized that we evolved this sensitivity to better detect the warning calls of our primate ancestors. π The long answer Hearing nails scraped on a chalkboard is a...
14 days agoΒ β’Β 3 min read
How do cruise ships turn around? 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 π The short answer Cruise ships turn around in tight spaces using a combination of bow thrusters, which move the front of the ship sideways, and azimuth thrusters, which rotate 360Β° to steer and propel the ship. These systems allow precise movements without relying heavily on tugboats. π The long...
21 days agoΒ β’Β 4 min read
Why does drinking something cold make you cough? This question came from a reader submission (thanks Lionel!). Has a curious question stumped you lately? Feel free to submit your own question here: Submit your question π The short answer Cold drinks may trigger coughing by rapidly cooling the esophagus and, by proximity, the trachea, which can cause the airways to tighten and lead to coughing. π The long answer While I've personally only experienced brain freezes when drinking a cold...
28 days agoΒ β’Β 3 min read
How is plastic being removed from the ocean? This question came from a reader submission (thanks Gary!). Has a curious question stumped you lately? Feel free to submit your own question here: Submit your question π The short answer Plastic is being removed from the ocean with boat-towed nets, but more effort goes into stopping it upstream by trapping it in rivers and cleaning beaches. Scientists are also testing ways to remove microplastics using filters, magnets, and microbes that clump or...
about 1 month agoΒ β’Β 8 min read
Why do we zone out? 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 π The short answer When we zone out, brain regions that process external stimuli decouple from our introspective default mode network, causing our mind to wander without us realizing. Zoning out gives the brain a chance to rest, reflect, and solve problems. π The long answer As you begin reading this...
about 1 month agoΒ β’Β 6 min read
Why do cartoon characters have four fingers? π The short answer Cartoon characters typically have four fingers to simplify animation and keep characters from looking too human, while Japanese anime characters have five to avoid negative cultural associations. I'm in end-of-the-year-reflection-mode and am working on a "Best of 2025" list to jot down life learnings, favorite books, tools I want to bring with me into the new year, etc. If you're interested in this more personal email from me,...
about 2 months agoΒ β’Β 6 min read
Why do leaves kill grass but snow does not? This question came from a reader submission (thanks Omar!). Has a curious question stumped you lately? Feel free to submit your own question here: Submit your question π The short answer Leaves can kill grass if they pile up thickly, blocking light and airflow, but a light layer can fertilize and support soil health. Snow usually doesnβt hurt grass and may help it survive winter by insulating it and adding moisture and nutrients, though problems...
about 2 months agoΒ β’Β 5 min read
Why do potatoes sprout? This question and the bonus question came from reader submissions (thanks to Sherry and Sean, respectively). Has a curious question stumped you lately? Feel free to submit your own question here: Submit your question π The short answer Potatoes sprout from small stem nodes called eyes when they are kept in warm, humid, and light conditions, using stored starch to fuel asexual reproduction and grow new plants. π The long answer If you leave a bag of potatoes sitting...
2 months agoΒ β’Β 5 min read
How are speed limits determined? This question came from a reader submission (thanks Arushi!). Has a curious question stumped you lately? Feel free to submit your own question here: Submit your question π The short answer Speed limits are set using a combination of engineering calculations, real-world driving behavior, and crash data. The goal is to balance safety and mobility based on how roads are designed and how drivers actually use them. π The long answer We've been trying to slow down...
2 months agoΒ β’Β 8 min read