It's just a router--like a handheld plunge-router, but direction and height are controlled by a computer. Not the sort of thing that every hobbyist has, but there are actually Instructables to show you how to make your own (of course!). He's not actually cutting it in two with the router. He's made two copies of the surface plot, flipped one over, and joined them side-by-side (in his software: Rhino). So the router just cuts the surface away on one side, then he cuts the two halves apart with the table saw, and folds them together.
Beautiful, but even with the advantages of a CNC router, it's way too finicky for me! FIFTEEN sanding steps? If I made it, the surfaces would be cloudy and there'd be bubbles in the epoxy :-)"...attach the two pieces together with a small gap between them..."Define "small", please? I assume we're not talking millimeters, because it would be impossible to get the epoxy in without bubbles. 1/2"?
You and me both!
If you mean the straight lines, that's just a trick of the light at the edges of the plexiglass.
Amazing Homemade Pizza Dough
Oh, right. Take a nice simple recipe, make it a great deal harder, and come up with something that won't be recognizably better for most people. There's no reason that you should set off a smoke detector with the OP's recipe.