skill

NightHawkInLight shows how to make radiative sky cooling paint from grocery and hardware store materials, including a novel calcium carbonate microsphere synthesis. The paint can cool a surface below ambient air temperature in direct sunlight without electricity.

Ben Krasnow of Applied Science shows how to make small batches of specialty glass with minimal equipment, including designing and making photochromic glass. He covers ingredients, melting and the challenges involved.

Matt Risinger covers installing a Zehnder ERV fresh-air system in a tight passive house, explaining balanced ventilation, the benefits of heat recovery and the costs involved.

Tech Ingredients builds a pair of large Voigt speakers and explains ported, transmission line and horn designs. It tests them in an anechoic chamber and uses constrained layer damping for the enclosure.

A reupload of Joel Spolsky's talk teaching spreadsheet users the Excel features they are probably missing, such as keyboard navigation, named ranges, tables and lookups. The original disappeared and this copy comes from the Wayback Machine.

Harry Schwartz gives a roughly hour-long tour of Emacs Org mode as an outliner, task manager, markup language and agenda tool. He demonstrates how he uses it for documents, presentations and todo lists.