Three Types of Magnetism

Will you be teaching magnetism soon?  You may wish to include some a demonstrations of paramagnetism and diamagnetism.

This video I made for UCLA will help you with these ideas. In the video, I discuss three different types of magnetism, superconductors, and different magnetic substances. This video will help you recognize on the differences between paramagnetism, diamagnetism, and ferromagnetism.

You might not think of water as being magnetic, but it is. It is diamagnetic.

Graphite, aluminum, and glass are magnetic too! They are diamagnetic or paramagnetic, but how can you differentiate between the two? Watching the video will help.

 And what about the third type, ferromagnetism?

Most people are familiar with ferromagnetism—it is one of the strongest forms of magnetism. For example, a magnetized piece of iron, nickel, or cobalt becomes a magnet in the presence of a magnetic field. The effect is strong and lasts even after the magnet is removed.

 Paramagnetism is weaker and more temporary than ferromagnetism. Aluminum is a good example of a paramagnet, and so is oxygen, which is attracted to magnets.

This image shows a few mL of liquid oxygen

So how can you tell if a substance is diagmagnetic or paramagnetic? You need to see how it aligns itself in a magnetic field.

Don’t get it just yet? Or maybe your students need to “see” this happening. Never fear, the video includes diagrams and demos to illustrate this concept. Just go watch it! What are you waiting for? 

Genius: Feynman Bio Review

Genius: The Life of Science of Richard Feynman

By James Gleick

Genre: Biography

  

Review: Having previously read James Gleick’s Isaac Newton, which I liked very much, I was interested to read his biography of Richard Feynman. For this biography, I would have preferred the title American Genius, because that is part of the story--Feynman growing up in Far Rockaway, New York in the 1920s and later, working on the atomic bomb project at Los Alamos. And then, ultimately he became an icon of American intellect.

To be fair, I already knew a lot about Feynman from other books associated with him. For example, I've read  Surely, You’re Joking, Mr.Feynman, his autobiography and the Feynman Lectures on Physics.

 I have also seen the Nova television series, The Pleasure of Finding Things Out.  Additionally, I have taken graduate-level courses in high energy particle physics and was at no time confused or intimidated by the science in this book.

Genius is written in chronological order, which I found enhanced its readability, because we often pick up with Feynman when he is already a grown man, who is telling jokes. However, the younger Feynman has been largely unexplored until this biography. I thought that was one of the more interesting parts of his life: pre-WWII America in which he was learning that he wanted to be a physicist.  In elementary and middle school, he set fire to his lab at home and won math contests.

 While a student at Princeton University, he created his own solution to the Feynman sprinkler problem: If you made water go into a spinning sprinkler, would it spin the other way? He solved the problem by pressurizing an aquarium; unfortunately, the aquarium and spilled water all over the lab!

Video discussing Feynman Sprinkler Problem 

Feynman’s autobiography paints a rosier picture of the WWII-era in which his young wife was sick and dying. Genius delves deeper into this part of his life. His first wife Arlene traveled with him to Los Alamos, but she was ailing from tuberculosis, and passed away, which affected Feynman deeply. Since his autobiography is more of a joke book, it doesn’t it delve into this part of his life, but the biography gives this part of his life the necessary treatment.

Many of us are interested in the human side of those scientists who helped build the atomic bomb, and Genius provides that insight. Like Gleick’s earlier biography Isaac Newton, Genius is extensively researched and thorough—you trust Gleick while reading. My main feeling about this book is that its treatment of the science is appropriately rigorous and complete for those of us physicists who are most interested in Richard Feynman.

In the video below, Gleick discusses his book and Feynman's life:

The book, like Feynman’s life, concludes with his role in the Challenger investigative committee. The anecdotes from that time period are covered in What Do You Care What Other People Think? in Feynman’s own words.  

I recommend this book to anyone who would like to get to know Richard Feynman. The charm and charisma of Richard Feynman are on the surface, and deeper value for society is as a scientist. Being a scientist in a non-scientific world is the springboard for all Feynman jokes, and the motivation for making a joke out of this condition is found by closely analyzing his life story.  

Successful NPTW Workshop

It was another productive Saturday yesterday at the New Physics Teacher Workshop, a workshop created by the Southern California chapter of the American Association of Physics Teachers (AAPT)! This workshop took place at Trash for Teaching in Gardena, CA, but we are hoping to expand our workshops to San Diego and Orange County in the future. 

On Saturday, December 7, 2013, the workshop was a wonderful success with almost thirty participants. In the morning, these new physics teachers observed lectures and demos to learn about topics including:

•  Circuits, Resistors, and Ohm’s Law 
• Magnets, Electromagnets, and Lenz’s Law
• Parallel Series: Ammeters/Voltmeters

In the afternoon, participants engaged in lab activities that they can bring back to their classrooms to create an interactive, hands-on environment.

 Labs included: 

• Using Your Plasma Globe: Ampere’s Law
•  Circuits Labs and Static Electricity and Static Tape
• Van de Graaf generator
• Using your Multimeter

     

     After this workshop, teachers were more comfortable with physics lab equipment. They also took home awesome science goodie bags that would allow them to create demos such as the Play-Doh resistivity demo. 

Xump donated these stylish bags to hold gifts for our participants,

such as D batteries, Play-Doh, Cartoon Guide to Physics, and more!

 

    Thank you to everyone who made this workshop successful, including the workshop leaders, sponsors, and participants!

Deceptively Simple Demos

We’ve all been there, right? We see a demo on YouTube and it looks perfectly simple, until…we try to recreate it. Even though I have performed many demos over the past ten years as a physics teacher, a “simple” demo is not always simple.

Recently, I tried to recreate a “Simple Photoelectric Effect Demo.” I was hoping to include it in one of my videos for new physics teachers. Almost an hour later, I still could not get the demo to work like the person in the video!

Remember that the video you see online is the best shot of what could be many failed attempts at creating the exciting effect of the demo you are watching. Do not give up if recreating the demo is not easy at first. Sometimes, you can ask a colleague for tips, or even look up tips for how to recreate the demo on the Internet. It might be possible to find advice relating directly to the demo you are observing. I found some advice about the photoelectric effect demo here: http://www.aapt.org/Programs/contests/upload/beehler.pdf 

and then I modified the materials I was using to try to improve my attempt at the demo.

For all of these reasons, before attempting the demo in front of your class, you should always try it out yourself. That way, you won’t waste class time if things go wrong and you won’t end up feeling frustrated or embarrassed in front of your class.

Here is what happened to me in detail: I watched the video for “Simple PhotoelectricEffect Demo.” This demo looks awesome and it was presented at a national meeting of the American Association of Physics Teachers (AAPT)! 

The demo uses a soda can, wire, tinsel, and a germ-sanitizing  UV-C light (which can be purchased online or at a local drugstore). 

As I said before, after multiple attempts, my demo was not working like the one onscreen.  

I realized that while I was using similar materials to what I saw online, I needed to use the exact materials (such as a wire instead of a nail and sandpaper instead of steel wool to rub the soda can) to create a successful demo. On another day, I finally located all of the necessary materials, and I was eventually successful in creating this demo—after more than an hour of trial and error.

This whole process made me think about the following question: When should you give up on a demo? 

Any thoughts, all of you teachers out there? Are there times when you should just play the video for your class instead?

Ultimately, the decision is up to you. It depends on how much you like to experiment and how much time and patience you possess.

If you cannot recreate a demo after watching on YouTube, you are not alone. Part of the experience of being a physics teacher is spending the time with the materials in your lab, getting to know your equipment, trying, failing, and persevering. Even if your demo is not dazzling on the first try, I hope you will still continue to integrate demos into your instructional practice and use visuals and interactive components in your physics teaching as much as possible.

Engaging Students through the Production of Student Films

As I mentioned in the previous entry, I taught a two week enrichment course for high school students about creating science films. 

Students engaged in the filmmaking process from pre-production to production to post-production. I wrote an article to advise teachers who are interested in creating movies with their students. 

This article includes advice on the three stages of film-making as well as five methods of engagement to use in the videos. I also share advice about storyboarding and scripting and additional resources for teachers to use. 

The students in my class worked on the script, storyboards, and of course, acted in the videos as lively hosts. 

Below is a still from the "Why is the Sky Blue?" video. Two student hosts scatter coffee creamer in an aquarium to show the appearance of blue light.

The article was published in the SCOPE: Curriculum Studies Newsletter, a publication of the National Association for Gifted Children, and is titled: "Engaging Students through the Production of Student Films: Advice for Successful Movies" Click on the title link above. 

If you read the article, I hope you will learn a lot and that you will consider creating science videos with your students. 

Why is the Sky Blue?

Why is the sky blue?

Does the sky reflect blue light? Does it only let blue light pass through? Does it emit blue light like a glowstick?

Many people have asked this question, but we don't always receive a full or accurate answer. During a two-week immersion course, a group of my high school science students created this video entitled, you guessed it, "Why is the Sky Blue?"

Vintage Physics Illustration

Falling Balloon and Two Types of Air Resistance

A piece of advice for all of you science teachers out there...try out a lab at home or in your classroom before presenting to the class. Here I am working on the falling balloon lab. My advice in this lab I created was to include a coin in the lip of the balloon and drop it. However, soon, I found the coin was too heavy and decided to change to paper clips. One paper clip weighs about 1 gram.

This lab is about air resistance, including laminar and turbulent air friction. I have noticed that many labs only consider air resistance as an experimental error. However, it is not hard to create a lab focusing on air resistance using household materials, which will work for either an Algebra or Calculus-based Physics Class.  I am still editing the lab, but I will share it soon!

 I like to try out each lab with students a few times before sharing my labs with other teachers, and so far the students have enjoyed the lab and learned a lot, using only a few simple materials, including:

·         Several balloons
·         Meter stick
·         Stopwatch
·         Several coins or paper clips
·         Gram scale

Trying to capture another falling balloon drop...

sorry, I did not have my slow motion camera with me!

I hope this entry will inspire you to think about household materials that you could use in a simple physics lab in your classroom. Applying your creativity to creating new labs or demos can keep your teaching fresh and exciting. 

The Physics of Jack O'Lanterns

HALLOWEEN! PHYSICS! PUMPKINS!

Here are some pumpkins that we carved last Halloween. 

This would make an awesome cover for The Physics Teacher magazine, am I right?

I am particularly proud of the Planck’s formula pumpkin, E=hv  which I carved, because at the time I was studying the history of Planck’s constant, h. This seems to be the same h in the formula for a derivative with lim h->0 . It is appropriate that this equation appears in the positive space of a pumpkin, because it is the formula for the energy quantization of light.

I hope this physics-themed pumpkin brings a smile to the faces of all you physics teachers and friends

 out there this Halloween!!

Work in Progress: Sound, Frequency, Wavelengths

First of all, thank to our friend Dean Baird over at Blog of Phyz for sharing the Lincoln Physics blog with his readers. 

http://phyzblog.blogspot.com/2013/10/go-check-out-lincoln-physics.html

Next, I will post some photos from the video-making progress from AAPT Films. On Sunday, I filmed a video about sound and measuring wavelengths using tuning forks and other tools. Tuning Forks, Test Tubes, and Antinodes, Oh My!

The video will include many active demos that you as teachers can share with students. 

 How is the length of a wavelength measured? Using nodes and antinodes...

Book Review: Pythagoras' Trousers

Book Review

Pythagoras' Trousers:

God, Physics, and the Gender Wars

by Margaret Wertheim

In Pythathagoras’ Trousers, the author Margaret Wertheim set out to write the wonderful history of all the women who contributed to physics over the centuries. However, she discovered that the history of women in physics was not wonderful at all. The information she found was more like the history of women being excluded from physics. She attributes this to the culture of physics, which has existed in an elitist, priest-like way since the days of Pythagoras and his secret society.

 In the past, the secrets of physics were written in Latin, a language only priests were likely to learn at the time. Latin was mostly a written language, not commonly spoken, and the layperson, both men and women, did not have access to such elite knowledge. Galileo started to write about science in Italian for the public to read, and this behavior definitely got him into trouble with the Church. 

 Marie Curie 

Who are the women who succeeded in physics? The book discusses several women, including Marie Curie and Hypatia, to name a few. 

 Hypatia

These women succeeded when an enlightened individual decided there was no reason a woman couldn’t learn the science that he knew. When there is such a strong current in the culture discouraging women to learn physics, to counter that current it takes a lot of encouragement for women to succeed, and that is still true today.

According to this book, there is a long history of women in physics being oppressed. This is a direct result of men preventing women from learning, which could be related to the patriarchal power structure of the Church.

Today, as we discuss the progress of women in STEM fields, many wonder why women are still underrepresented in the field of physics. After all, women are well-represented and respected in almost all fields of science, while physics alone lingers with an underrepresentation of women.  The author posits that “physics as a religion” may turn women away from the field. I won’t tell you all of her opinions; however, she discusses the search for the god particle and the almost religious hero worship of physicists like Einstein.

Why should you read this book? As a physicist or physics teacher, you will learn more about what women must overcome to become eminent in the field of physics. What does it take to mentor women into becoming successful physics? After reading, you might be more likely to take that extra step in encouraging your female physics students to stick with it. You could be that enlightened individual who encourages young women to persevere in the field, just like the mentors of Hypatia and Marie Curie.

After reading this book, I hope you will be inspired to rewrite the story of physics from an exclusive club to a more inclusive and inviting culture of physics.

The Movie Seen 'Round the World

Recently, I received an email requesting to show one of my videos abroad, at a museum! See below:

“For the Museum Night of Delft, the Netherlands, I want to ask you for your permission to show “Can Dogs See in Color?” in public at the night of Oct 25.

We (art students) are programming a video program regarding humans and technology and would be pleased to use this video in our selection.

Hope to hear from you as soon as possible.

Yours,

Johannes Kronenberg”

Of course, I agreed. Isn’t it cool? Next week, in the Netherlands, they will be watching my video. But you don’t have to wait! You can watch it here and now (below):

.