Hydraulic jump - Effects on a jump of shape of object jet lands on

 Here's a really interesting experimental idea that can lead to a vast number of variations for students to create an original research study. Set up a hydraulic jump experiment, which consists of a water source and a stream of falling water (i.e. the water jet in a jump experiment) that lands on a hard surface. 

The idea is to put a 3D object of whatever shape at the location where the jet of water is supposed to land on a flat surface. The water in the jet flows over the surface of the object, and then onto the flat surface, where the experimentalist then measures whatever jump and pattern that takes place. Here is an example of an experiment where hemispheres, spheres, cubes and cylinders were used. Students can use whatever shaped objects they have lying around their house or school lab, or they can design and create any shaped 3D object with a 3D printer, ceramics, clay, or other material that is available. 

Numerous options await - be creative with the shapes of the objects being used. Measure the flow patterns and any jumps that form under a wide variety of conditions. You can vary the height from which the water jet falls, the diameter of the jet, the dimensions of the object on which a water jet falls, the material from which the 3D object is made, the orientation of the object relative to the jet, and so on. One may nbe interested in trying to find a mathematical parameter that should be added to theoretical treatments of hydraulic jump, when one needs to account for the shape of the surface water lands on. 

6 Questions Physicists ask when evaluating a scientific claim of discovery

 To many, science is the process of discovery and trying to find the 'facts' of how the world works. It is supposed to be unbiased, nonpartisan, and pure. But don't ever forget that science is done and practiced by human beings, all of whom are imperfect, have biases, and make mistakes, just like everyone else. We are not 'all knowing' and have all the answers, and we never will. 

Having said this, what is the real story for how scientists go about their work? How do we know whether or not to believe a scientific claim by others? How and why should we evaluate others' work to justify their conclusions, especially when it is something important in the field or something never seen or claimed by anyone before? 

Check out this nice piece, from Symmetry magazine (this is very good if you like particle physics), which uses examples from particle physics to demonstrate how science is actually a little messy, but most importantly human - and 'facts' in science do change! Scientists are willing to change their minds over time as new results, often the result of new technologies and methods and data sets, because discovering real truth is a long, difficult process. There always is and should be debate and skepticism, but also open minds that are willing to accept new results that contradict old ones. There needs to be an open process or peer reviewed publications and presentations at conferences, so other experts can review a colleague's work openly and completely to check for mistakes or misinterpretations of the data. This is why it takes time to do science the 'right way.' 

A great message from a former NASA astronaut for STEM students - how to think about making the world a better place through STEM

 Many of us are not familiar with the United Nations' Sustainable Development Goals, established in 2015. These are 17 goals most nations of the world agreed to work on and make significant progress in by 2030, and most of them will require STEM to develop viable solutions to make a better, more sustainable world for humanity. 

To make a different kind of connection with the mindset, skills, knowledge, and approach to work on the SDGs, check out the thoughts of former teacher and astronaut Ms. Dottie Metcalf-Lindenburger. She talks about how her training and experiences in NASA overlap with what we all need to make progress in creating a better world for future generations. This video presentation comes from the SOS4Love Project, and was presented at the 2020 UN Peace Week last week. Please check it out!