Throw in some curves and things get interesting, especially when you can control the curve with a touch of your finger, as with this variable surface convex mirror. The video below starts off with ...

Each of the ELT’s custom mirrors is a feat of optical design. Dr Vernet describes the 14ft (4.25m) convex M2 mirror as “a piece of art”. But perhaps the M1 and M4 mirrors best express the ...