Scientific American.com

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.

When Israeli aircraft recently struck a uranium-enrichment complex in the nation, Iran could have been days away from achieving “breakout,” the ability to quickly turn “yellowcake” uranium into bomb-grade fuel, with its new high-speed centrifuges

President Trump will attend the G7 summit on Sunday in a nation he threatened to annex. He will also be an outlier on climate issues

Switching on air-conditioning during extreme heat doesn’t have to make us feel guilty—it can actually boost power grid reliability and help bring more renewable energy online

The decision to help a friend or stranger—and the amount of help that one chooses to give—may be powerfully shaped by the brain’s basolateral amygdala

Physicists are a step closer to using quantum computers for simulations that are beyond the ability of any ordinary computers

Evidence from Earth’s deep past suggests dramatic subduction zones can spread like a contagion

A near-complete census of our interstellar neighborhood hopes to answer how stars, brown dwarfs and rogue planets form throughout the universe

The Asian needle ant looks ordinary, but its sting can be worse than a fire ant’s and can be dangerous for anyone who has experienced anaphylaxis