Energy Labs: Electrical Fields and Magnetic Fields

As mentioned previously, the companion website to the PBS show Einstein's Big Idea includes activities related to the three parts of Einstein's equation E=mc2: energy, mass and velocity. We worked our way through them, substituting and adjusting where necessary. Not all of them were as successful or illuminating as we hoped, but they were quick and easy to do and got us started on physics labs. The instructions below include the adaptations we made to the instructions from the PBS teachers' material.

The energy lab consists of seven activities, which they suggest you set up at different stations. We did these over the course of a few days. On day one, we did the electrical and magnetic field activities. Here is what the teacher's guide calls its "learning objectives:"
Students will be able to:

• explain what the E in E = mc2 represents.
• name different kinds of energy.
• show examples of how one kind of energy can be converted into another kind of energy.
• describe how a field can exert a force and cause an object to move.

Electrical Field Lab

• one plastic spoon for each person
• 10 cm x 10 cm piece of wool or fur (we used a woolen scarf, and the hair on our heads!)
• pieces of plastic foam cup, crumbled into bits
• pieces of paper, about 0.5 cm by 1 cm each

1. Rub a plastic spoon with a piece of wool, some fur, or your hair. Place the spoon next to a small piece of paper. Can you make the piece of paper stand on edge and move back and forth?

2. Try to pick up several pieces of paper at the same time by touching the spoon to one edge of each.

3. Recharge the spoon by rubbing it again. Try to drop a small bit of plastic foam into the spoon from different heights above it.

Explanation: Students are examining the effects of an electric field produced by rubbing a plastic spoon on fur. Once the spoon is charged (negatively), it will attract an uncharged object like a piece of paper through electrostatic induction. The large negative charge on the spoon repels the electrons in the piece of paper and leaves the side of the paper near the spoon slightly positive. (Positive charges-in the nucleus of each atom within the paper-hardly move at all.) Then, the negative spoon attracts the now positive side of the paper. If students are careful in their approach to the paper, they should be able to make it "dance."

Plastic foam becomes instantly negatively charged when in contact with another negatively charged object. The bits of plastic foam acquire a negative charge when they touch the spoon and are repelled immediately. It is impossible to catch a piece of plastic foam, no matter how close to the spoon it is held. If students claim they can, have them recharge their spoons. Watch the pieces of foam cup go veering away from the spoon in this video:




Magnetic Field

• several types of magnets, including bar or horseshoe
• small shallow cardboard box
• piece of white paper (cut to fit box)
• small container of iron filings (I found one in an old chemistry set.)

1. If the box is not white inside, fit a white piece of paper into the bottom of the box.

2. Center one or more of the magnets under the box.

3. Sprinkle iron filings into the box over the magnet. Lines of magnetic force should begin to become visible. (See photo at top.)

Explanation: Students should realize that the field from the magnet is exerting a force on the iron particles. The filings will align with the north and south field lines. Watch as the lines form in the video below:

Physics2000 - Relativity First!

Continuing my investigation into the idea of teaching modern physics before classical, I've come across a website called Physics2000. Here's a description:

Physics2000 is a college level introductory physics course that begins with special relativity, ends with quantum mechanics, and in-between covers the usual topics with a 20th century focus. This approach eliminates the great divide between classical and modern physics.

BEGIN WITH SPECIAL RELATIVITY?

Introducing Einstein’s special relativity in Chapter 1 means that you cannot rely on the usual mathematical techniques because no mathematics has been discussed yet. You have no choice but to focus on the physical ideas like the behavior of clocks and measurements of distance. The result is that you remove the mathematical fear factor usually associated with the subject. The only mathematics you need is the Pythagorean theorem.

According to the website, the Physics2000 course can be ordered on CD, including the text (there are calculus and non-calculus versions) and videos, for $10. Several of the chapters are available to preview online. It looks worth checking out.

NOTE: There is also an old, apparently unrelated website from the University of Colorado called Physics 2000. It contains online interactives on modern physics from a conceptual viewpoint.

Trailblazing Website Puts Scientific Discoveries Online

Britain's Royal Society puts rare scientific manuscripts online (AFP)

LONDON — Historic manuscripts by Sir Isaac Newton, Benjamin Franklin and other ground-breaking scientists will be published online for the first time, Britain's Royal Society said Monday. The society, the world's oldest scientific institution, will release famous literature on the web that it has published in its journals over the centuries as part of celebrations to mark its 350th anniversary. The works include a 1770 scientific study confirming that composer Wolfgang Amadeus Mozart was a genius and, more recently, acclaimed British scientist Stephen Hawking's early writings on black holes. Called Trailblazing, the interactive site contains 60 articles chosen from among the 60,000 that have appeared in the Royal Society's journals.

"The scientific papers on Trailblazing represent a ceaseless quest by scientists over the centuries, many of them Fellows of the Royal Society, to test and build on our knowledge of humankind and the universe," said Royal Society president Lord Martin Rees. "Individually they represent those thrilling moments when science allows us to understand better and to see further."

Newton's theory on light and colours in the 1600s, that continues to provide the basis for theoretical physics, will be published along with a gruesome account of a 17th-century blood transfusion. A paper by Benjamin Franklin, one of the founding fathers of the United States, will also be released on an experiment to fly his kite in a storm to prove that lightning is electricity rather than a supernatural force. The Royal Society will also be running events over the next 12 months to celebrate its anniversary "to inspire scientists, families, young people and interested members of the public alike to see further into science," Rees said.

Einstein's Big Idea

If it seems crazy to start our study of physics with relativity, then let me say that I had in fact, originally drawn up a nice teaching plan which followed a more traditional physics sequence -- motion and mechanics through December, heat and thermodynamics in January, electricity and magnetism in February -- and lightly touched on everything after classical physics in May or June. (The list of topics I made up came directly from the Physics4Kids website.) But as I began to look at the material to be covered and the possible activities we could do (some of which the kids did many years ago when a friend taught a co-op class using the book Teaching Physics with Toys), I thought about how much of this stuff I had retained from my own formal science classes in high school. The answer was, not much.

If you have been following me through our adventures with chemistry and biology, you know that I am an English major with a geeky bent who got high marks in high school science and then promptly forgot everything I “learned.” My goal is to do some interesting activities that might help my kids and I grasp some of the concepts of each science discipline with worrying about getting the “right result” or memorizing a lot of jargon. Right after I made up my traditional teaching plan, I read the essay mentioned in the post Quantum Mechanics in Middle School? And I realized that – as with biology, when we focused on microorganisms where much exciting research is being done today – what I really wanted to find out about was the new stuff being done in physics. In the few weeks that I’ve been working on putting this course together, I’ve heard several times that the theory of relativity is the basis of all modern physics. I imagine that it is the equivalent of evolutionary theory to biology – to study the subject without starting with that game-changing idea is to get a skewed picture of how the field is treated today.

All of which leads us to Einstein’s Big Idea, the PBS NOVA episode which we watched last week. I literally pulled it off the library shelf without really knowing what it was about. But as luck would have it, I think this has been an excellent entry point for our study of physics. Einstein’s Big Idea uses actors to recreate the lives of Einstein and his predecessors: Michael Faraday, Sir Humphry Davy, Antoine-Laurent Lavoisier, James Clerk Maxwell. There are also comments from living physicists and David Bodanis, author of the book E=mc2 on which the episode was based. Taking this personal approach, the show highlights something I never realized: how many women were involved in the development of modern physics. Along the names already mentioned, we meet Mme Lavoisier, who greatly helped her husband in his work; Emilie du Châtelet, math genius and companion of Voltaire; Lise Meitner, who split the atom and helped prove Einstein’s theory, but who had to leave Germany when the Nazis began persecuting Jewish scholars. And of course Mileva Maric, who gave up her own physics studies in college when she became Einstein's first wife and mother to his son. All of these women have been neglected in the popular history of science, and it was a revelation to discover their existence.

Beyond the personalities, Einstein’s Big Idea did a good job of explaining the concepts involved in a way that most teens and adults can understand, and showing how Einstein’s theory was built upon the work of others while forging a new path at the same time. I highly recommend this video to anyone who wants to begin to understand the basis of all physics today.

Physics Learning Cycles

Last week the kids and I watched a great PBS NOVA episode called Einstein's Big Idea, about the discoveries which led up to E=mc2. I'll be giving my review in another post, but I wanted to mention the wonderful companion website with activities you can do at home. We'll be doing the energy activities later this week.

However, as sometimes happens, one of the activities looks too subtle to be worth the set-up involved. And in looking for another activity I could substitute to demonstrate the same concept, I found an archive of physics activities at the Arbor Scientific catalog website. I really like what the author, Chris Chiaverina, has to say about introducing science concepts using something called "Learning Cycles." It seems to describe exactly what the NOVA website activities are designed to do:

Introducing Newton's Laws with Learning Cycles

As many of you know, the Learning Cycle is an approach to science instruction developed by Atkin and Karplus in 1962 while working on the SCIS (Science Curriculum Improvement Study) project. This approach puts the phenomena first. Names and numbers are brought into the picture only after students are allowed direct contact with the phenomena. Although there are a number of variations on the theme, the essential learning cycle consists of three phases. These phases include exploration, concept development and application. The "Learning Cycle" method may be used to teach virtually any topic in physics.

Here is how Chiaverina sets up a Learning Cycle activity:

• An exploratory is a collection of introductory science activities that relate to a single topic or concept. Exploratories provide students with a common experiential base while igniting their interest.
• The activities are arranged as numbered stations around the room. Manipulatives at each station provide opportunities for exploration and discovery.
• The exploratory uses a guided inquiry approach. The guidance is provided through instructions and questions that accompany each station. The teacher remains in the background and assists only when asked.
• The activities may be done in any order.
• A non-judgmental approach is used. At this point, the teacher should be focusing on the quality of a student’s reasoning, not whether an answer is right or wrong. The teacher is given an opportunity to listen to students dialog with peers and formulate explanations. Student pre-conceptions are revealed during this phase of the learning cycle.
• Exploratories encourage student engagement. Intriguing manipulatives tend to get even the most disinterested students involved. Since discrepant events leave the students with a need to know, the class discussion that follows an exploratory is teacher led, but student-driven.
• Exploratories provide qualitative experiences. Quantitative laboratory work is done later.
• Placing instructions at each station eliminates duplicating costs. Laminating the instructions allows them to be reused.

The Arbor Scientific physics articles archive is in the sidebar. If it is as good as it looks, we'll be doing some of these activities as well.

Why Does E=mc2 and Why Should We Care?

The Colbert Report	Mon - Thurs 11:30pm / 10:30c
Brian Cox
www.colbertnation.com
Colbert Report Full Episodes Political Humor U.S. Speedskating

Physicist Brian Cox, author of a new book about relativity, explains nuclear physics to comic Stephen Colbert.

Quantam Mechanics in Middle School?

I was searching for middle school level physics teaching resources (the level I think worthwhile for general enthusiasts) when I came across this interesting essay about how to use science education to get kids actually interested in science. It was written by Douglas E. Richards, author of a series of middle school science thrillers called The Prometheus Project, and appeared on a website called EarthSky. Here's a taste:

Bringing relativity, quantum physics, and genetic engineering to middle school

Imagine a seventh-grade science teacher announcing to her class, “For the next week, we’re going to do something different. First, you’ll never, ever, be tested on the material we’ll be covering. Second, we’ll be talking about scientific ideas so awesomely cool that you’ll swear I’m making them up. Concepts such as Einstein’s theory of relativity, quantum physics, cosmology, genetic engineering, and nanotechnology. Amazing science that I promise will be more surprising and harder to believe than anything you’ve ever read in a Harry Potter novel.”

Do you think this would get the class’s attention? You bet it would.

Given the importance of science to our collective futures, it isn’t enough for us to teach sets of facts for given scientific topics. It’s our job to stoke young imaginations as well. To show how fascinating, surprising, and mind-blowingingly cool science can be. To show that along with the rote memorization of scientific knowledge, science is about the infinity of what we still don’t know. It’s about world-changing ideas; about experiments that show the universe to be, in the words of Arthur Eddington, “not only stranger than we imagine, but stranger than we can imagine.”

And this is something that we, as a society, are not doing as well as we should.