Issues
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Cover Image
Cover Image
Cover: Bird flocks, fish schools, and insect swarms have all been studied through the lens of active-matter physics. Studying human crowds, though, presents logistical and ethical challenges. The story on page 8 describes one research team’s solution: observing and analyzing the crowd of revelers at a long-running Spanish festival, a scene from which is shown here. The unique collective phenomena that emerge can be described with a physical model that treats the crowd as a continuous medium. (Photo courtesy of the Bartolo Lab, ENS de Lyon.)
Readers' Forum
Clarifications on the Chien-Shiung Wu feature
Comments on “Careers by the numbers”
Search and Discovery
Dense crowds follow their own rules
When thousands of people are packed into a confined space, collective dynamics takes over. The phenomenon can be described with a physical model.
Plasma channel guides electrons to 10 GeV
Femtosecond-scale laser pulses make a plasma waveguide that helps wakefield-surfing electron bunches keep their energy focused.
Updates
Record-setting cosmic neutrino breaks in a new telescope
An analysis of the highest-energy neutrino ever detected has researchers questioning the frequency at which such energetic particles pelt our planet.
A meticulous thermodynamic recipe for cooking eggs
Cycling eggs between boiling and tepid water creates the firm white typically attained by soft-boiling and the creamy yolk usually achieved by sous vide cooking.
The protection required to deliver a powerful underwater punch
The structure of a smasher mantis shrimp’s clubs protects their tissue from damaging shock waves.
Issues and Events
Not all quantum jobs require quantum skills
To go commercial, quantum science needs a sizable workforce.
Ukrainian physics journal celebrates a half century
The editors of Fizyka Nyzkykh Temperatur (Low Temperature Physics) have continued publishing despite Ukraine’s war with Russia.
Q&A: Frank Close probes quarks and popularizes science
He has written books on quarks, protons, spies, nuclear threats, and more.
US science leaders offer blueprint for maintaining global leadership in STEM
A new report on how the US can realize its potential in STEM warns that China is pulling ahead.
Features
Earth’s magnetic dipole collapses, and life explodes
The present-day magnetic field protects life, but an ancient phase when it nearly collapsed corresponded with a key step in evolution. Changes in the planet’s deep interior may have started it all.
Peter Shor on the genesis of Shor’s algorithm
The theoretical computer scientist describes his path to the factoring algorithm that helped spark interest in quantum computing.
Demythologizing quantum history
Celebrating the 100th anniversary of quantum mechanics in 2025 without providing appropriate context risks reinforcing a long legacy of hagiography and hero worship.
New Products
Quick Study
The no-cloning theorem
People gather, copy, and distribute information all the time. But in the quantum world, the laws of physics impose a severe restriction on copying: It is impossible to make a perfect copy of an unknown state.
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