 So we're talking about extraction today and most of the time when when people talk about extraction of minerals or talk about liquid resources so oil and gas and many of you may have seen pictures of gushers of the early oil wells that that people hit and so that the You drill down you'd hit over pressured oil and it would squirt out of the top of the oil rig Now a lot of these early wells and some of the famous ones were in Pennsylvania were very very very shallow so you didn't need particularly sophisticated equipment and so you'll you'll also go back into these archives and these pictures of of these TP like structures that had the drill rigs in them Basically just putting a pipe down hitting these over pressured zones and of course the oil would squirt out the top And once it stopped squirting out the top you pump out the oil that you had so that's extraction so you're getting the oil and then you process it and people use it to drive their cars and whatnot so that was relatively cheap and easy to do and The way people recognized where to go drill for oil initially was where it was just seeping out of the ground and There were places like Baku in the caucuses in in in Asia where it was seeping out of the ground or in Iraq where it was seeping out of the ground and Of course all this shallow oil is very very easy to produce You don't have to have very very strong pumps to get it out And of course if it's gushing out then you just let it gush out so the history of extraction is really a story of engineering and as those easy Oil fields the really shallow ones were exploited and used up The oil companies and the exploration companies had to start looking deeper and deeper and in more exotic locations and had to use more sophisticated imagery seismic Profiling things like that But just initially it was just a tube going down to very shallow depths at 100 meters or so or less and You'd extract the oil