# Archive

## Latest Articles

### Evolving Bacteria Can Evade Barriers to ‘Peak’ Fitness

Paradoxically, natural selection can sometimes seem to block organisms from evolving useful adaptations. But a new study of “fitness landscapes” and antibiotic resistance in bacteria shows that life still finds a way.

### Meet Strange Metals: Where Electricity May Flow Without Electrons

For 50 years, physicists have understood current as a flow of charged particles. But a new experiment has found that in at least one strange material, this understanding falls apart.

### Pierre de Fermat’s Link to a High School Student’s Prime Math Proof

How Fermat’s less famous “little theorem” got mathematicians young and old to play with prime-like Carmichael numbers.

### In the Gut’s ‘Second Brain,’ Key Agents of Health Emerge

Sitting alongside the neurons in your enteric nervous system are underappreciated glial cells, which play key roles in digestion and disease that scientists are only just starting to understand.

### Researchers Refute a Widespread Belief About Online Algorithms

Three computer scientists have disproved a long-standing conjecture about a fundamental problem involving imperfect information.

### The Astonishing Behavior of Recursive Sequences

Some strange mathematical sequences are always whole numbers — until they’re not. The puzzling patterns have revealed ties to graph theory and prime numbers, awing mathematicians.

### AI System Beats Chess Puzzles With ‘Artificial Brainstorming’

By bringing together disparate approaches, machines can reach a new level of creative problem-solving.

### During Pregnancy, a Fake ‘Infection’ Protects the Fetus

Cells in the placenta have an unusual trick for activating gentle immune defenses and keeping them turned on when no infection is present. It involves crafting and deploying a fake virus.

### Rogue Worlds Throw Planetary Ideas Out of Orbit

Scientists have recently discovered scores of free-floating worlds that defy classification. The new observations have forced them to rethink their theories of star and planet formation.