What is Electrical Resistance?

 Every electrical device you have used has something called electrical resistance. If you've noticed electrical devices get warm - perhaps a calculator or cell phone or a stereo or computer that's been on - that heat is the sign of electrical resistance. 

When electric current flows through anything, where the current is a flow of electrons, those electrons collide with atoms within the lattice of the material. Even good conductors like copper wire and gold, will get warm...there are no perfect materials, and atoms get in the way of the flowing electrons! 

This video will use a simulation to get some images in our heads as to what happens at the micro-level. And also remember this: in mechanics, all collisions have some loss of kinetic energy. So every electron loses KE in a collision to that atom, and the atom then vibrates in place a little faster. From chemistry, we know that the temperature of a material depends on the average KE of its atoms and molecules - so if there is an increase in vibrational KE of the atoms of a material, it feels warmer to us! 

Materials that create few collisions for the electrons in the current have low resistance (small numbers of ohms), and if there are a lot of collisions there is a higher resistance (larger number of ohms, the unit of resistance). 

See another video for how we handle multiple resistors in circuits, in combinations of series and parallel, that we need for circuit analysis. 

New site for our work with our Malawi friends: EMPATHY

 I just wanted to add that we will be maintaining a site for the fundraising and work done with our friends in Malawi, Africa. With some $15,000 raised and provided to Andrews Nchessie, there are amazing results on the ground as far as the farms they have planted, raised, maintained and harvested, feeding some 1500 children year-round so they can be healthier, happier and in school learning full-time! Check out our EMPATHY site: Evanston Malawi Partnership Against The Hunger of Youth. 

Public Science - Zooniverse

 You may have heard of public science, or maybe not. In most fields of science, there are datasets that are SO LARGE that there are not enough actual scientists in those fields to look at it all. And there are some things that people are still better at seeing and identifying or classifying from a dataset than computers are. How do scientists handle the analysis of such large datasets? 

Bring in the global public! 

Some non-professionals are even getting their names on published papers for their contributions to new discoveries, such as new exoplanets.

Check out the Zooniverse website - there are over 80 big data projects that you can participate in, no experience required. Check out all the options, in dozens of different fields! 

Learn About Quantum Mechanics: The Quantum Atlas

 One of the better sites I have seen in order to learn about the fundamental concepts behind quantum mechanics is The Quantum Atlas. It has wonderful animations & interactive simulations, which bring some challenging ideas to life in a more understandable way. Kudos to the group Joint Quantum Institute at the U. of Maryland! 

If you enjoy making videos...

 Here is an international contest sponsored by the United Nations Alliance of Civilizations (UNAOC). It is called PLURAL+, and has a focus on submitting videos dealing with issues in migration, diversity and social inclusion, which many ETHS students are interested in. Could be a good chance to get your personal message out in a creative way, to the world! Check it out.

Here is one example by a Greek student, who is dyslexic and 12 years old, of a friend who teaches her English. 

Project Excite - A Model for Positively Affecting Academic, Opportunity Gaps

 For nearly twenty years, Evanston Township High School (ETHS) was part of a long-term effort, in collaboration with Northwestern University and District 65, to study and try to find a solution to a major problem seen in so many diverse communities and schools around the country - despite great effort, countless conversations and numerous programs, too often we see academic achievement gaps between white students and students of color, that are already in place at young ages and show no signs of improvement through high school graduation. How and why is it that results in things like test scores, grades, participation in honors and advanced placement (AP) classes, participation in academically inclined extracurricular activities and clubs, graduation rates, and college acceptance and attendance become very different between demographic groups, despite the fact that the students all grew up and attended the same schools, with the same resources and teachers, and in theory had exposure to the same potential opportunities? And is it possible to diminish and perhaps even eliminate such gaps before students graduate from the K-12 public school system? 

These were the research questions of Project Excite, and the goal was to determine if there is a systematic, comprehensive, sustained and long-term program or method that would have any significant effect on closing the achievement and opportunity gaps in the community.

Excite no longer exists, and there are no dedicated efforts trying to address achievement gaps in E-town. We hope to resurrect something soon, on a wider scale. It provides a model that demonstrated a long-term, comprehensive, inclusive and more holistic approach to build up not only academic skills and knowledge base, but more importantly self-confidence and self-esteem for the students as well as families, can reduce and eliminate the measured achievement gaps. We also saw consistent increases of Excite students into honors and AP courses when in ETHS, which is part of the opportunity gap that has historically seen underrepresentation of students of color at these academic levels.

Here's a summary of the original Project Excite, and how it was run.

Climate Modeling: EdGCM

 A former professional level climate modeling package has been turned into an educational modeling example and option to do climate modeling research for students. Called the Educational Global Climate  Model, EdGCM, it is a user-friendly, open-source program students can use and work with. We recently had a student figure out how to run the program, and this is a sample video presentation of what he did. 

For computer savvy students wanting to pursue climate science and modeling, where they can control and change numerous environmental parameters and then run simulations to determine predicted outcomes from the science mathematical models within EdGCM, they can actually do the research! 

A very cool zero-emissions boat: solar + hydrogen

 If you enjoy cool engineering and energy efficiency, climate change innovations, alternative energies, and all related to these topics, check out this really cool ship! It is all solar, wind and hydrogen fueled! 

Voyager mission - still making discoveries

 To the juniors, we were just thinking about the Voyager mission, and how NASA scientists and engineers were able to figure out how to get these two probes, launched in 1977, to the big outer planets and then out of the solar system! This article outlines what one of the probes is doing, outside the boundary of the solar system (the heliopause) and is measuring what the interstellar medium is like. Fascinating, and we still get data from the probe some 44 years after launch and 14 Billion miles away!! Check it out. 

For the Historians: Interesting history to the start of western science, 2500 years ago

 Check out this truly interesting article outlining the start of the modern science approach, coming from Greece some 2500 years ago. Anaxagoras, whom I cannot recall ever reading about, came to Athens, Greece, and may have interacted with Socrates, who of course had the pupil Plato and then Aristotle, to develop the philosophical foundation of Western society. Anaxagoras was a prominent figure in having an off-shoot or purely philosophical reasoning to natural philosophy, which is a term that lasted millennia until we changed it to science! 

Let's appreciate the geniuses from SO long ago. I wonder how many of our names will still be remembered in the year 4521!