exc (excetra)

And there was value in the thing, clearly, that they were certain of. But what is the application? In a matter of hours, they had given it into everything from mass transit to satellite launching, imagining devices the size of jumbo jets. Everything would be cheaper. It was practical, and they knew it. But above all that, beyond the positives, they knew that the easiest way to be exploited is to sell something they did not yet understand. So they kept quiet.