Welcome

21st Century Scholars

Presentation by John Swez

Department of Physics

What is the definition of “Physics”

• Webster’s 9th new Collegiate Dictionary gives: physics [physica, pl, natural science, fr. Gk, of physikos of nature … ] 1. a science that deals with matter and energy and their interactions in the fields of mechanics, acoustic, optics, heat, electricity, magnetism, radiation, atomic structure, and nuclear phenomena

The Game of Physics• Physics is much like playing a game. The game

is to find the rules of nature. We cannot always understand why the rules are what they are, but we can still play the game and test the rules as we play. We test the rules with experiments.

• Mathematics is used a lot in physics because it communicates the rules of the game in a precise and concise way.

• As with any other language knowing what certain words and symbols mean is important. For example c is used frequently for the speed of light (3 x 108 m/s) or 300 million meters/second.

Eddy Currents a rule of nature

• When a magnet is dropped down a metallic tube, the changing magnetic field created by the falling magnet pushes electrons in the metal tube around in circular, eddy-like currents. These eddy currents have their own magnetic field that opposes the fall of the magnet. The magnet falls dramatically slower than it does in ordinary free fall in a nonmetallic tube.

I cheated with the rules of the game!

• I used a small metallic (non-magnetic) cylinder

• The small cylinder was easy to “palm” with a small magnet about the same size

• The magnet behaves differently than the non-magnetic cylinder

• Changing Magnetic Fields generate opposing currents.

Let’s Play Some Games

• Dropping Objects (Gravity)– How Objects Fall

• Radioactivity– What’s radioactive in the world around us

• The World of Waves– Sound Waves– Light Waves

• Levitation (The Meisner Effect)

Cell phone conversation

Mom..Dad…

“Some prof here at ISU is trying to poison me with radioactive candy!”

Prof answers:

No, only the bowl is radioactive. It is a Fiestaware bowl. Have you seen these before? Only the orange-red color is radioactive!

Despite the noise of the GM counter, they are relatively safe if not used to be eaten from.

“The World Year of Physics 2005 is a United Nations endorsed, international celebration of physics. Events throughout the year will highlight the vitality of physics and its importance in the coming millennium, and will commemorate the pioneering contributions of Albert Einstein in 1905. Through the efforts of a worldwide collaboration of scientific societies, the World Year of Physics brings the excitement of physics to the public and will inspire a new generation of scientists. http://www.physics2005.org/

What is the “World Year of Physics 2005”

From the “World Year of Physics 2005 Website

Why 2005?“In 1905, his year of wonders, Einstein 1) made major contributions to the classical kinetic theory of atoms and molecules; 2) resolved the conflict between classical mechanics and the optics and electrodynamics of moving bodies; and 3) laid the foundations for the quantum theory of light and matter."

From a talk by Dr. John Stachel Professor Emeritus of Physics and Director, Center for Einstein Studies Boston University given on Friday, February 4, 2005   8:00 p.m McKenna Hall Auditorium, University of Notre Dame

What you should remember about Physics

Fiziks is Phun!

Some Important Web Hits

• http://www.physics2005.org/ [physics 2005.org]

• http://newton.indstate.edu/swez [newton.indstate.edu/swez] {my website}

• http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html {a superb site}

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