Issues
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Cover Image
Cover Image
cover: This cross-sectional snapshot from a simulated cylindrical cell shows the temperature in turbulent Rayleigh–Bénard convection, the flow of fluid heated from below and cooled from above. Tiny plumes of rising (red) and sinking (blue) fluid are visible in the snapshot, taken close to the cylinder’s lower, warm plate. For more details on strongly turbulent convection, turn to the article by Detlef Lohse and Olga Shishkina on page 26. (Simulation courtesy of Richard Stevens and Roberto Verzicco.)
Readers' Forum
The clean-energy challenge redux
Search and Discovery
A new proxy for Earth’s past energy imbalance
Oxygen-isotope measurements of ocean-bottom organisms are an excellent indicator of the atmosphere’s radiation flux.
Electron scattering provides a long-awaited view of unstable nuclei
Nuclear reactions produce a plethora of short-lived artificial isotopes. Figuring out what they look like has been a challenge.
Issues and Events
Extreme weather makes monitoring snowpack increasingly relevant
A dedicated satellite would provide global coverage to improve understanding of the hydrologic cycle and inform water-use and risk-management strategies.
The future has arrived for securing confidential data
Though quantum computers are still a decade or more away, NIST is finalizing new encryption standards now to replace current vulnerable protections.
Articles
Ultimate turbulent thermal convection
Recent studies of a model system—a fluid in a box heated from below and cooled from above—provide insights into the physics of turbulent thermal convection. But upscaling the system to extremely strong turbulence remains difficult.
“Peaceful” nuclear explosives?
Proponents of Project Plowshare argued that using nuclear explosives for peaceful means offered technical and economic advantages. But getting the biggest bang for the buck didn’t outweigh the varied environmental and sociopolitical costs of their use.
They were astronomers
Unlike at most other observatories in the early 20th century, women working at Yerkes Observatory were able to earn graduate degrees. Here are some of their stories.
Books
A relativistic dialog
General Relativity: The Theoretical Minimum, Leonard Susskind and André Cabannes
A timely retrospective
On the Origin of Time: Stephen Hawking’s Final Theory, Thomas Hertog
New Products
Obituaries
James Burkett Hartle
Quick Study
Bats thrive in cluttered spaces
The winged mammals produce high-frequency sounds and listen to their echoes from surrounding objects to track down insects to eat. Counterintuitively, the interference from the echoes of clutter nearby can help.
