Nearly every object we interact with in our lives has a mass, but where does this mass come from? Modern physics says matter acquires its mass from interaction with a physical vacuum—it is not an empty space, but contains a complex structure. Investigating the system of a meson—a composite particle made of a quark, an elementary particle, and its anti-matter, anti-quark—bound to an atomic nucleus, a mesic nucleus, provides precious insight into the vacuum structure, or mass generation mechanism. Scientists are now one step closer to further understanding the origin of mass thanks to new experimental results on a completely new type of mesic nucleus.

In a new Nature Physics publication, University of Amsterdam researchers introduce human-made materials that spring to life. These ‘metamaterials’ don’t just learn to change shape, but can autonomously adapt their shape-changing strategy, perform reflex actions and move around like living systems do.

Near-infrared spectroscopy, or fNIRS, offers a way to monitor brain activity without surgery or radiation by tracking changes in blood flow and oxygenation. Light sources placed on the scalp send near-infrared light into the head, and detectors measure the light that scatters back. Because this light must pass through the scalp and skull before reaching the brain, the measured signal always includes a mix of superficial and cerebral contributions. Separating those signals has long been a central challenge for fNIRS researchers.