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Trade impulse clothing purchases for botanical dyes, upcycled apparel, creative mending, flexible sizing, and more

Toxic cigars; dueling with a swordfish

Letters to the editors for the March 2025 issue of Scientific American

To boost mood and manliness, men are spending lots of money on the hormone testosterone—yet they may see trouble instead of benefits

One hundred years after the Scopes trial, religious ideologues are still trying to supplant evidence-based curricula with myths, to the detriment of a well-informed society

AI is shedding new light on the 12,000-year conversation between cats and their humans, suggesting that house cats wield a far richer vocabulary than once thought

Iranian Shahed drones, Ukrainian quadcopters and the U.S.’s Golden Horde program reveal three paths to massed autonomy, and each rewrites the rules of air defense

I study social media for a living. Here’s what parents need to know so that kids can use it safely and productively

Deadly temperatures put great stress not just on human life but also on the economy, infrastructure, agriculture and health care

Critics fear that U.S. Department of Health and Human Services chief RFK, Jr., known for his antivaccine views, has picked a crucial CDC committee that will be a “disaster for public health”

Researchers have measured the brain’s faint glow for the first time, hinting at a potential role of “biophotons” in cognition

To build safe but powerful AI models, start by testing their ability to play games on the fly

Using a notion called integer partitions, mathematicians have discovered a new way to detect prime numbers while also connecting two areas of math in an unexpected way

The first images of the cosmos taken by the world’s largest digital camera onboard the Vera C. Rubin Observatory are about to be released to the public. Here’s how to watch the action live

Major changes hit a key CDC vaccine advisory panel, ocean acidification crosses a critical threshold, and new research reveals an unexpected threat to pangolins.