It’s a regrettable reality that there is never time to cover all the interesting scientific stories each month. In the past, we’ve featured year-end roundups of cool science stories we missed. This year, we’re experimenting with a monthly collection. January’s list includes papers on using lasers to reveal Peruvian mummy tattoos; the physics of wobbly spears and darts; how a black hole changes over time; and quantum “cat states” for error correction in quantum computers, among other fascinating research.
Tracking changes in a black hole over time
Left: EHT images of M87* from the 2018 and 2017 observation campaigns. Middle: Example images from a general relativistic magnetohydrodynamic (GRMHD) simulation at two different times. Right: Same simulation snapshots, blurred to match the EHT’s observational resolution.
Credit:
EHT collaboration
In 2019, the Event Horizon Telescope announced the first direct image ever taken of a black hole at the center of an elliptical galaxy, Messier 87 (M87), located in the constellation of Virgo some 55 million light-years away. Astronomers have now combined earlier observational data to learn more about the turbulent dynamics of plasma near M87*’s event horizon over time, according to a paper published in the journal Astronomy and Astrophysics.
Co-author Luciano Rezzolla of Goethe University Frankfurt in Germany likened the new analysis to comparing two photographs of Mount Everest, one year apart. While the mountain’s basic structure is unlikely to change much in that time, one could observe changes in clouds near the peak and deduce from that properties like wind direction. For instance, in the case of M87*, the new analysis confirmed the presence of a luminous ring that is brightest at the bottom, which in turn confirmed that the rotational axis points away from Earth. “More of these observations will be made in the coming years and with increasing precision, with the ultimate goal of producing a movie of what happens near M87*,” said Rezolla.
Astronomy and Astrophysics, 2025. DOI: 10.1051/0004-6361/202451296 (About DOIs).
Lasers reveal Peruvian mummy tattoos
A tattooed forearm of a Chancay mummy.
Credit:
Michael Pittman and Thomas G Kaye
Humans across the globe have been getting tattoos for more than 5,000 years, judging by traces found on mummified remains from Europe to Asia and South America. But it can be challenging to decipher details of those tattoos, given how much the ink tends to “bleed” over time, along with the usual bodily decay. Infrared imaging can help, but in an innovative twist, scientists decided to use lasers that make skin glow ever so faintly, revealing many fine hidden details of tattoos found on 1,200-year-old Peruvian mummies, according to a paper published in the Proceedings of the National Academy of Sciences.
