Magazine
November-December 2025
November-December 2025
Volume: 113 Number: 6
The large-scale structure of the universe was set by the tiniest of forces—quantum fluctuations—during the incredibly brief period of rapid expansion that occurred just after the Big Bang. These initial moments, the only period in which both quantum and gravitational dynamics have ever significantly interacted, created a gravitational noise still visible in the primordial light that astronomers call the cosmic microwave background (CMB). In The Unlikely Primeval Sky, Craig Hogan explores our current understanding of the CMB and the information that can be derived from it, including the fact that our cosmos is strangely smooth and surprisingly flat compared to the vast majority of likely universes. Is this a fluke, or a call for new physics? (Cover art by Illustris Collaboration.)
In This Issue
- Astronomy
- Biology
- Chemistry
- Communications
- Environment
- Evolution
- Medicine
- Physics
- Policy
- Psychology
- Technology
Rethinking Adult ADHD
Margaret Sibley
Medicine Psychology
The diagnostic category for attention-deficit/hyperactivity disorder has become more inclusive, but that does not mean the condition is being overdiagnosed.
Growing the Great Green Wall
Maxim Samson
Environment
A collaborative effort spanning the width of Africa is planting a verdant barrier of trees and traditional agriculture to protect the Sahel from desertification.
