Artist’s impression of an inner accretion flow and a jet from a supermassive black hole when it is actively feeding, for example, from a star that it recent tore apart. Image: ESO/L. Calçada

Signals suggest black hole emits a jet of energy proportional to the stellar material it gobbles up. On Nov. 11, 2014, a global network of telescopes picked up signals from 300 million light years away that were created by a tidal disruption flare – an explosion of electromagnetic energy that occurs when a black hole rips apart a passing star. Since this discovery, astronomers have trained other telescopes on this very rare event to learn more about how black holes devour matter and regulate the growth of galaxies.

Scientists from MIT and Johns Hopkins University have now detected radio signals from t...

A powerful new 4D printing technique could one day allow manufacturers to produce electronic devices and their wiring in a single process. Credit: H. Jerry Qi

Scientists report that they have developed a powerful new printer that could streamline the creation of self-assembling structures that can change shape after being exposed to heat and other stimuli. They say this unique technology could accelerate the use of 4D printing in aerospace, medicine and other industries. “We are on the cusp of creating a new generation of devices that could vastly expand the practical applications for 3D and 4D printing,” H. Jerry Qi, Ph.D., says. “Our prototype printer integrates many features that appear to simplify and expedite the processes used in traditional 3D printing...

Rice University graduate student Nicole Carrejo analyzes a sample of K2(SL)6K2, an injectable hydrogel researchers believe may help accelerate the healing of diabetic ulcers. Credit: Jeff Fitlow/Rice University

Invention could accelerate tissue growth compared with current treatment. A hydrogel invented at Rice University that is adept at helping the body heal may also be particularly good at treating wounds related to diabetes. The Rice lab of chemist and bioengineer Jeffrey Hartgerink reported this week that tests on diabetic animal models showed the injectable hydrogel significantly accelerated wound healing compared with another hydrogel often used in clinics. The study appears this week in the American Chemical Society journal ACS Biomaterials Science and Engineering...

Artist’s conception of Scholz’s star and its brown dwarf companion (foreground) during its flyby of the solar system 70,000 years ago. The Sun (left, background) would have appeared as a brilliant star. The pair is now about 20 light years away. / Michael Osadciw/University of Rochester

New evidence of the passage of Scholz’s star. About 70,000 years ago, a small reddish star approached our solar system and gravitationally disturbed comets and asteroids. Astronomers from the Complutense University of Madrid and the University of Cambridge have verified that the movement of some of these objects is still marked by that stellar encounter.

At a time when modern humans were beginning to leave Africa and the Neanderthals were living on our planet, Scholz’s star – named after the German astronom...