Discover magazine has an article on a ‘Whole-House Machine’ which can build mortal walls among other things. Overrated? Maybe. Interesting? Definitely: …In a sunny laboratory at the University of Southern California, a robotically controlled nozzle squeezes a ribbon of concrete onto a wooden plank. Every two minutes and 14 seconds, the nozzle completes a circuit, topping the previous ribbon with a fresh one. Thus a five-foot-long wall rises�a wall built without human intervention.
The wall is humble but portentous. �If you can build a wall, you can build a house,�…