Scientific American.com

Why Testosterone Therapy Could Harm Some Men, though It Could Help Others
To boost mood and manliness, men are spending lots of money on the hormone testosterone—yet they may see trouble instead of benefits
American Education Demands a Fact-Based Curriculum, Not Religious Ideology
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
What Is Your Cat Trying to Say? These AI Tools Aim to Decipher Meows
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
How Drone Swarms Work—From Iran’s Shahed Attack to Ukraine’s Operation Spiderweb
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
What I Wish Parents Knew about Social Media
I study social media for a living. Here’s what parents need to know so that kids can use it safely and productively
Extreme Heat Is the Biggest Threat to Insurers and Businesses
Deadly temperatures put great stress not just on human life but also on the economy, infrastructure, agriculture and health care
Who Is on RFK, Jr.’s New Vaccine Panel—And What Will They Do?
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”
Your Brain Is Glowing, and Scientists Can’t Figure Out Why
Researchers have measured the brain’s faint glow for the first time, hinting at a potential role of “biophotons” in cognition
Truly Intelligent AI Could Play by the Rules, No Matter How Strange
To build safe but powerful AI models, start by testing their ability to play games on the fly
Mathematicians Hunting Prime Numbers Discover Infinite New Pattern for Finding Them
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
See Vera C. Rubin Observatory’s First Images Live with These Watch Parties
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
RFK, Jr., Fires CDC Vaccine Panel Experts, Ocean Acidification Hits Dangerous Levels, and Pangolins Face Hunting Threat
Major changes hit a key CDC vaccine advisory panel, ocean acidification crosses a critical threshold, and new research reveals an unexpected threat to pangolins.
Could Iran Have Been Close to Making a Nuclear Weapon? Uranium Enrichment Explained
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
Five Climate Issues to Watch When Trump Goes to Canada
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
Air-Conditioning Can Help the Power Grid instead of Overloading It
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
How a Tiny Brain Region Guides Generosity
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
Quantum Computers Simulate Particle 'String Breaking' in a Physics Breakthrough
Physicists are a step closer to using quantum computers for simulations that are beyond the ability of any ordinary computers
Tectonic Plates Can ‘Infect’ One Another with Earth-Shaking Subduction Zones
Evidence from Earth’s deep past suggests dramatic subduction zones can spread like a contagion
Mapping Nearby Stars Could Solve a Deep Cosmic Mystery
A near-complete census of our interstellar neighborhood hopes to answer how stars, brown dwarfs and rogue planets form throughout the universe
Invasive Asian Needle Ant’s Sting Is Painful, Can Cause Anaphylaxis
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