Energy landscapes of a molecule during a light-driven chemical reaction. Like a golf ball rolling on a curved putting green, the molecule can follow reaction paths on these surfaces. Credit: Greg Stewart/SLAC National Accelerator Laboratory

An extremely fast “electron camera” at the Department of Energy’s SLAC National Accelerator Laboratory has produced the most detailed atomic movie of the decisive point where molecules hit by light can either stay intact or break apart. The results could lead to a better understanding of how molecules respond to light in processes that are crucial for life, like photosynthesis and vision, or that are potentially harmful, such as DNA damage from ultraviolet light.

In the study, researchers looked at a gas whose molecules have 5 atoms each...

This is an artist impression of the triple star system PSR J0337+1715, which is located about 4,200 light-years from Earth. This system provides a natural laboratory to test fundamental theories of gravity. Credit: NRAO/AUI/NSF; S. Dagnello

Einstein’s understanding of gravity, as outlined in his general theory of relativity, predicts that all objects fall at the same rate, regardless of their mass or composition. This theory has passed test after test here on Earth, but does it still hold true for some of the most massive and dense objects in the known universe, an aspect of nature known as the Strong Equivalence Principle? An international team of astronomers has given this lingering question its most stringent test ever...

An impression of the encounter between the Milky Way galaxy and the smaller Sausage galaxy about 8 billion to 10 billion years ago. The record of this ancient encounter is still preserved in the velocities and chemistry of the stars.
Credit: V. Belokurov (Cambridge, UK); Based on image by ESO/Juan Carlos Muñoz

An international team has discovered an ancient and dramatic head-on collision between the Milky Way and a smaller object, dubbed the “Sausage” galaxy. The cosmic crash was a defining event in the early history of the Milky Way and reshaped the structure of our galaxy, fashioning both its inner bulge and its outer halo, the astronomers report in a series of new papers.

The astronomers propose that around 8 billion to 10 billion years ago, an unknown dwarf galaxy smashed into our own ...

Joule, Sun et al.: “Heat-insulating multifunctional semitransparent polymer solar cells” https://www.cell.com/joule/fulltext/S2542-4351(18)30242-3

Environmentally friendly building trends have boosted the popularity of window coatings that keep heating and cooling costs down by blocking out unneeded parts of sunlight. They have also inspired scientists and engineers to create thin, see-through solar cells to turn windows into miniature electricity generators. Researchers in China have gone a step further and combined these two functions into one window-compatible material that could double the energy efficiency of an average household. Their work appears July 3 in the journal Joule.

“Building-integrated photovoltaics are a great example of a market where silicon photovoltaics, despite thei...