Toggle light / dark theme

Sam Baron, Australian Catholic University.

Black holes form natural time machines that allow travel to both the past and the future. But don’t expect to be heading back to visit the dinosaurs any time soon. At present, we don’t have spacecraft that could get us anywhere near a black hole. But, even leaving that small detail aside, attempting to travel into the past using a black hole might be the last thing you ever do.

Summary: Lab-created retinal cells created from human stem cells can reach out and connect to neighboring cells, a new study reports. The cells have the capacity to replace damaged retinal cells and carry sensory information. The findings could pave the way for clinical trials for the treatment of a range of diseases associated with vision loss and blindness.

Source: University of Wisconsin.

Retinal cells grown from stem cells can reach out and connect with neighbors, according to a new study, completing a “handshake” that may show the cells are ready for trials in humans with degenerative eye disorders.

Interest in gallium lagged in the past, partly because of the unfair association with toxic mercury, and partly because its tendency to form an oxide layer was seen as a negative. But with increased interest in flexible and, especially wearable electronics, many researchers are paying fresh attention.

To make bendable circuits with gallium, scientists form it into thin wires embedded between rubber or plastic sheets. These wires can connect tiny electronic devices such as computer chips, capacitors and antennas. The process creates a device that could wrap around an arm and be used to track an athlete’s motion, speed or vital signs, for instance, says Carmel Majidi, a mechanical engineer at Carnegie Mellon University.

Neutron stars and black holes may be stellar corpses, but they are among the most active celestial objects. They produce some of the highest-energy radiation ever observed, and scientists have long puzzled over the physics that underlies the process powering their energetic emissions.

Now, in a recent paper published in Physical Review Letters, a Dartmouth physics major and an assistant professor have proposed a new theory that explains how can be very quickly released with explosive energy into charged particles in these .

Similar magnetic explosions also occur closer to home, setting off and the Northern Lights. They can be observed wherever charged gases, called plasma, are found—even in a lab, says Matthew Goodbred ‘23, the paper’s lead author.

Using NASA’s Fermi spacecraft, Chinese astronomers have investigated the variability and spectral behavior of gamma-ray flares in a distant blazar known as 3C 279. Results of the study, presented in a paper published in the Publications of the Astronomical Society of the Pacific, could help researchers better understand the flaring activity of blazars.

Blazars are very compact quasars associated with at the centers of active, giant elliptical galaxies. Based on their optical emission properties, astronomers divide blazars into two classes: (FSRQs) that feature prominent and broad optical emission lines, and BL Lacertae objects (BL Lacs), which do not.

At a distance of about 5 billion , 3C 279 is an FSRQ with an estimated black hole mass of 300–800 million solar masses. It is a bright and powerful source in the high– sky and is known as the first blazar showing strong and rapid variability at GeV energies.