The NetBSD Project released NetBSD 9.5, the final update in the NetBSD 9 branch containing selected security and stability fixes, and declared the netbsd-9 branch end-of-life. Users on netbsd-9 are urged to upgrade to newer releases such as NetBSD 11.0 (or the upcoming 11.1) or NetBSD 10.2.
Explains impedance matching — how systems are altered to transfer or block energy efficiently — with examples across mechanics, acoustics and optics (transmissions, trumpet flares, anti‑reflective coatings, anechoic foam). The piece also likens atmospheric CO2 to an impedance matcher for infrared radiation and suggests stratospheric dust as a geoengineering way to tune Earth’s radiative coupling.