> This technology is great. Not yet it's not. There's a world of difference between using samples of concrete "about the size of a button" and scaling up to so

> This technology is great. Not yet it's not. There's a world of difference between using samples of concrete "about the size of a button" and scaling up to something the size of the foundation of a house. And that just gets it to "buildable". To get to "ubiquitous" it also has to be cheap.