Time evolution of the contour surfaces of the lapse α and the shift vector βi for the head-on collision of two puncture black holes of equal mass M=1 at times t=0,5,7,8,10M and t=15M, from top left to bottom right. Phys. Rev. D 97, 084053, 2018; doi:10.1103/PhysRevD.97.084053

Scientists develop simulation code for new generation of supercomputers. What happens when two black holes merge, or when stars collide with a black hole? This has now been simulated using a novel numerical method. The simulation code ‘ExaHyPE’ is designed in such a way that it will be able to calculate gravitational waves on the future generation of ‘exascale’ supercomputers.

The challenge in simulating black holes lies in the necessity of solving the complex Einstein system of equations...

Photo shows Hawra Karim (left) and Seema Tiwari-Woodruff. Credit: I. Pittalwala / UC Riverside

Study shows that ‘good inflammation’ promotes axon myelination. Researchers at the University of California, Riverside, now report that indazole chloride, a synthetic compound that acts on one form of the body’s estrogen receptors previously shown to reduce multiple sclerosis symptoms in mouse models, is able to do both: remyelinate (add new myelin to) damaged axons and alter the immune system.

“While additional translational studies are required, indazole chloride and similar drugs may represent a promising new avenue of treating the underlying loss of myelin in multiple sclerosis,” said Seema Tiwari-Woodruff, an associate professor of biomedical sciences in the School of Medicine, who led the m...

In a background magnetic field, represented by the cyan arrows, two electrons are propagating to the right, executing identical gyromotion. A circularly polarized electromagnetic wave approaches the upper electron from the left.
Credits: NASA

Encircling Earth are two enormous rings – Van Allen radiation belts – of highly energized ions and electrons. Various processes can accelerate these particles to relativistic speeds, which endanger spacecraft unlucky enough to enter these giant bands of damaging radiation. Scientists had previously identified certain factors that might cause particles in the belts to become highly energized, but they had not known which cause dominates.

Now, with new research from NASA’s Van Allen Probes and Time History of Events and Macroscale Interactions during Sub...

Illustration of emissions from a tidal disruption event shows in cross section what happens when the material from a disrupted star is devoured by a black hole. The material forms an accretion disk, which heats up and emits vast amounts of light and radiation. The emissions we are able to see from Earth depend on our viewing angle with respect to the orientation of the black hole. Credit: Illustration by Jane Lixin Dai

A star that wanders too close to the supermassive black hole in the center of its galaxy will be torn apart by the black hole’s gravity in a violent cataclysm called a tidal disruption event (TDE), producing a bright flare of radiation...