Because of the kinds of differences that are presented when it comes to what you might think of as ownership of these sometimes diffused intangible things, the rules can be quite different in some important ways between intellectual property and conventional physical property. There can also be, there are, some major differences among different forms of IP. Copyright and patent, for example, differ in a very important respect, which is that copyright only protects against copying. Whereas, patent protects absolutely. It protects even against independent inventors of the same technology. In copyright, if two different people compose the same melody there's no copyright infringement, but in patent law if two people invent the same drug to cure the same disease there would be patent infringement if one of them goes ahead and uses their invention. Then there are differences, some major differences, between IP and physical property. At least between different forms of IP. Patent and copyright exist only for a limited period of time. Patent and copyright protection. A patent law protects an invention only for 20 years. Copyright law generally protects an authors' creation for the authors' lifetime plus 70 years. After that a work enters the public domain. That is not the situation when it comes to land. We don't say, at least under our law in general, we don't say after a period of time land just goes back into the public domain and whoever is the first to stick their flag in it gets it, or rather it becomes public and can never be owned again. We don't say that. So, that there is a very significant difference between the way at least two of the most important forms of IP operate compared to property in physical resources. There are lots of other differences along the way, but there are also differences among different types of physical property as well. Ownership of water rights is a different undertaking than ownership of a car. The rules differ in those respects and the same thing is true across IP. It can be hard to come up with a singular generalization that captures all of these things. At the same time, what is clear is that there are some pretty strong basic similarities between IP and physical property, but also at many different stages some important differences in the way that IP operates.