Model Comparison in the Introductory Physics Laboratory

Model comparison is at the heart of all scientific methodologies. Progress is made in science by constructing many models (possibly of different complexities), testing them against measurements, and determining which of them explain the data the best. It is my observation, however, that in many introductory physics labs we provide students with the materials and methods to verify the “correct” model of the experiment they are performing, e.g. measuring “g” or verifying the period of a pendulum. In this way, we do our students a disservice and don’t allow them to experience the richness and creativity that constitutes the scientific enterprise. Limiting the lab to the “correct” model can have its uses—for example, getting the students to practice the proper methods to measure lengths and times or to support the specific theory covered in the lecture portion of the class. However, when students perform these labs, they come to view these activities as repetitive and mechanical, reinforcing the notion that science concerns not the true exploration of nature but simply the verification of what we already know. By verifying what we already know, the laboratory experience does not improve overall understanding and can mislead students about the methods of science overall

The Total Takings Myth

For almost thirty-five years, the U.S. Supreme Court has attempted to carve out a total takings doctrine within its regulatory takings jurisprudence. Most regulatory takings claims are evaluated under the “ad hoc” threefactor test first articulated in Penn Central Transportation Co. v. City of New York. Exceedingly few of these claims are successful. But the Court has identified certain categories of government actions that are compensable takings per se, otherwise known as total takings. This began in 1982 with Loretto v. Teleprompter Manhattan CATV Corp., where the Court held that a land use ordinance requiring a landowner to endure a permanent physical occupation of a portion of her property is always a compensable taking. Ten years later, in Lucas v. South Carolina Coastal Council, the Court held that a land use restriction depriving an owner of all economically viable use of her property is also compensable per se. Finally, in 2015, in Horne v. Department of Agriculture, the Court extended its total takings jurisprudence to personal property, announcing that the government appropriation of personal property is a per se compensable taking. Although the Court has had more than three decades to articulate theoretical justifications for its total takings jurisprudence and to provide guidance for lower courts in determining when a regulation constitutes a total taking, it has failed to do so. This failure reflects the underlying reality that the total takings doctrine is a myth. More particularly, the categories that the Court has identified as constituting total takings are analytically incoherent, and the terms the Court has used to demarcate total takings from regulations that are not per se compensable cannot be applied in the real world. As a result, lower courts struggle to apply the total takings doctrine and the case law remains in utter disarray. In fact, lower courts have resorted to creating “shadow” total takings doctrines that rely on obvious distortions of the plain meaning of outcome-determinative terms and deflect attention from the fundamental question of whether compensation is warranted. This Article argues that the Court’s attempt to create a total takings doctrine has failed, and that the Court should repudiate it. It demonstrates that the Court’s initial total takings opinions were conceptually incoherent and woefully undertheorized. And it shows that attempts by lower courts to rehabilitate the doctrine by crystallizing the bright-line rules through careful and consistent application were doomed to, and did, fail. This Article also explains why the entire enterprise was misguided from the start. Although bright-line rules have their place, it is not in the heart of regulatory takings doctrine, which is premised on concerns for fairness and justice in distributing the burdens of land use regulation. Last term, the Court had a perfect opportunity to begin the process of repudiating the total takings myth. Murr v. Wisconsin was a run-of-the-mill regulatory takings case masquerading as a Lucas-type total takings claim, and it presented the Court with a vehicle to either remedy the central doctrinal incoherence of Lucas’s bright-line rule or to overrule Lucas and turn its attention to the much needed task of clarifying and refining the Penn Central test. Instead, by offering a new multifactored test in a sort of regulatory takings “step zero,” the Court in Murr merely exacerbated the core flaws of the Lucas bright-line rule. Now, more than ever, it is imperative that the Court recognize and begin to dismantle the total takings myth

Using Python to Program LEGO MINDSTORMS Robots: The PyNXC Project

LEGO MINDSTORMS® NXT (Lego Group, 2006) is a perfect platform for introducing programming concepts, and is generally targeted toward children from age 8-14. The language which ships with the MINDSTORMS®, called NXTg, is a graphical language based on LabVIEW (Jeff Kodosky, 2010). Although there is much value in graphical languages, such as LabVIEW, a text-based alternative can be targeted at an older audiences and serve as part of a more general introduction to modern computing. Other languages, such as NXC (Not Exactly C) (Hansen, 2010) and PbLua (Hempel, 2010), fit this description. Here we introduce PyNXC, a subset of the Python language which can be used to program the NXT MINDSTORMS®. We present results using PyNXC, comparisons with other languages, and some challenges and future possible extensions