Monday, December 23, 2013

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? 

Saturday, December 14, 2013

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!

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.  

Sunday, December 8, 2013

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!