 The first big engineering breakthrough was developed by a guy named Howard Hughes, and he was the Elon Musk of his time. He was not only an engineer, but an entrepreneur, and he recognized that he had a monopoly on something, and so he developed a drill bit that everybody used and still uses to this day. This is the drill bit that Howard Hughes designed, and it's designed to go down and just spin, and as it's spin, these three cones basically grind up the rock that's in front of it, and you'd end up with a tube within a tube, so you'd end up pumping down drilling fluid, which is often what they call mud because they add different types of weighted clays to the water that they're drilling with, and that of course helps lubricate this, and then that ends up going up on the outside and squirting out at the top of the drill string, and these nested cones is what Howard Hughes invented, and he's made an absolute fortune on it because everybody needed to use this particular design to drill deeply, and drill deeply they did, and they're still used to this day, so it was his patent that made that happen. Before that, you basically had drill heads that were like this, and they were just round tubes with a cutting, and they could go into relatively soft sediments, and this one just happens to be from the Ocean Discovery program that I used when I was out in the North Atlantic, and that's great for soft sediments, but this will grind up all kinds of hard rock, whether it's sedimentary, metamorphic, or igneous rock, this will grind it away. The harder it is, the slower it goes, but it'll still work, and so what this allowed was extraction to much, much deeper depths, and so that was the first big engineering breakthrough that carried through much of the 20th century, and allowed drilling for oil reservoirs and extraction down several kilometers.