The 50 most-cited articles in Physics Today, 2018

Research reveals that labs are more effective when their goal is to teach experimental practices rather than to reinforce classroom instruction.

By carefully orchestrating atomic-scale interactions, one can coax hard surfaces to slide against one another with virtually no resistance.

To the extent that individuals interact with each other in prescribed ways, their collective social behavior can be modeled and analyzed.

When the discrete time-translation symmetry of isolated, periodically driven systems is spontaneously broken, a new phase of matter can emerge.

How stars are born from clouds of gas is a rich physics problem whose solution will inform our understanding of not just stars but also planets, galaxies, and the universe itself.

A mix of proteins, polymers, lipids, and tightly bound but fluid shells of water molecules may account for a healthy joint’s ultralow friction.

Evidence shows that patterns of inequity in physics drive talented women out of the field. Here’s what physicists can do to overcome them.

The response of a material to a periodic, large strain manifests the internal mechanisms by which the substance relieves stress. But Nature does not readily reveal her tricks.

The power of organic chemistry is opening new possibilities for building customized two-dimensional materials.

The rich molecular structures of polycyclic aromatic hydrocarbons—essentially planar flakes of fused benzene rings—and their fullerene cousins are revealed through their vibrational and electronic spectra.

Although quenching one’s thirst may be the primary appeal of soda pop or a cold beer, there’s a lot of physics in the drinks’ two-phase flow.

The rapid neutron-capture process needed to build up many of the elements heavier than iron seems to take place primarily in neutron-star mergers, not supernova explosions.

Perhaps the most important reason to understand the deep history of a field is that it is the right thing to do.

Vision begins when the eye's optical system-the cornea, iris, and crystalline lens-projects an image onto the retina, the thin and nearly transparent sheet of neural tissue that lines the back of the eye (see figure 1). Photoreceptors located at the back of the retina transduce incident photons into neural signals that are relayed to the brain. Those signals form the basis for visual perception. In humans, cone photoreceptors, which number about 6 million, dominate the central region of the visual field and are responsible for color and high-resolution day vision. Rod photoreceptors, which number about 120 million, dominate the periphery and mediate night vision.

The half-century-old handbook commonly known as Abramowitz and Stegun enters the 21st century.

Surface molecular structure is the arbiter in the contest between energy and entropy that largely determines how ice and snow crystals develop.

The superconducting transition’s exquisite sensitivity to heat underlies a maturing technology for detecting photons.

An unusually broad set of experiences helped prepare Stanford Ovshinsky to recognize a phenomenon that forever changed solid-state physics.

The gravitational waves accompanying the merger of two massive compact objects encode the distance to the merger without the usual appeal to a hierarchy of length scales.

The laureates circumvented an intrinsic limitation in laser technology to develop an amplification protocol now found in nearly every high-power, ultrafast system.

Disorder, confinement, and symmetry breaking contribute to the formation of new phases when liquid helium-3 is infused in a highly porous random solid such as a silica aerogel.

A glut of cheap natural gas, coupled with rapid increases in wind energy, is accelerating a decline in the US commercial nuclear industry when carbon-free energy has never been more important.

When two carbon sheets are misaligned by a mere degree, striking changes result.

Critics dismiss the idea of scrubbing meaningful amounts of carbon dioxide from the air, but proponents say the approach could be scaled up for the job.

The combined effects of ozone, sunlight, and atmospheric waves turn the near void of Earth’s mesosphere into a refrigerator capable of producing vast clouds of water ice.

Two research groups demonstrate the coherent interaction between the spin of a single electron and a single microwave photon.

During the first half of the second millennium, the American West was plagued by a succession of decades-long dry spells. Could it happen again?

Magnets built with high-temperature superconductors are at the heart of efforts to demonstrate a burning plasma in a compact device.

Delicious, flaky croissants owe their wonderful texture to the complex, multiscale structure of butter or related fats.

Optical tweezers have endured as an invaluable laboratory tool for manipulating molecules and other small particles.

News from multiple messengers—neutrinos, cosmic rays, and photons—provides clues to the cosmic sources that create some of the most energetic particles observed on Earth.

Although the second African American to receive a physics PhD in the US faced obstacles because of his race, he blazed trails in spectroscopy and pedagogy.

We welcome Frank Schweitzer's article, "Sociophysics" (Physics Today, February 2018, page 40), which looks back at antecedents of current physics applications to social phenomena. Schweitzer calls for overcoming challenges that derive from method-driven (physics) perspectives. To his list of examples we propose to add another: problem-driven work. We—an urban planner and two physicists—started out with social conflict, looked at its real problems, and reached for statistical mechanics tools to explore its dynamics over time.Social conflicts are embedded in complex systems and are themselves complex. They defy description. Moreover, rarely do we know enough about the links between cause and effect to predict outcomes or even to narrow their range meaningfully. Therefore, it is difficult for conflicting parties using negotiation, decision, and planning theories to strategize effectively.For example, as Democrats and Republicans confront each other over climate change, security threats, and immigration policies, they harbor a range of attitudes, from total opposition toward the other…

Sophisticated materials science lies behind the fabrication of the crunchy, low-fat food enjoyed in cereals and snacks worldwide.

With a train of ultrashort light pulses, researchers disentangle energetically similar photoionization channels—and solve a seven-year-old puzzle.

Planetary astronomer Bradford Adelbert Smith, who led the imaging team on the Voyager mission to the outer solar system in the 1980s, died peacefully at his home in Santa Fe, New Mexico, on 3 July 2018 from complications from myasthenia gravis. Bradford Adelbert Smith NASAPPT|High resolutionBorn on 22 September 1931 in Cambridge, Massachusetts, Brad graduated in 1954 from Northeastern University with a BSc in chemical engineering. Despite that early training as a chemical engineer, Brad’s first love was astronomy. After college, he spent two years in the US Army, working as an astronomer at the White Sands Missile Range in New Mexico, where he began a long and productive association with Clyde Tombaugh, the discoverer of Pluto. His first project, with Tombaugh at Lowell Observatory, was a search (with negative results) for possible natural satellites of the Moon during the November 1956 lunar eclipse.Soon thereafter, Brad followed Tombaugh to New Mexico State University (NMSU). In 1958 they established a program of systematic, ground-based telescopic imaging of the planets to…

If you listen carefully to the sound that sparkling wine makes after it is poured, you’ll hear the size distribution of the ringing bubbles.

With the end of the Cold War, most physicists turned their attention away from the nuclear threat. It is now time for us to reengage in the debate over how to reduce the dangers from nuclear weapons.

Interference much like that observed in two-slit experiments can be seen in the outcomes of chemical processes in which multiple reaction mechanisms lead to the same final state.

A familiar climate anomaly turns out to have a recently recognized relative.

Mathematics and technology combine to make a virtue of the graininess imposed on astrophysical images by atmospheric turbulence.

A 250-year-old effect still has some surprises in store.