Peruvian mummy tattoos, the wobbly physics of spears and darts, quantum "cat states," and more.

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

Lasers reveal Peruvian mummy tattoos

Sforza Castle’s hidden passages

Physics of wobbly spears and darts

Quantum “cat states” for error detection

New twist on chain mail armor

Kitty robot mimics headbutts

...read more at arstechnica.com