Accelerated Beats

Listening to this audio file you will hear the left and right hands beat together at 4 beats/measure for one measure.

Then at the start of the 2nd measure the right hand accelerates its beat rate speeding up by 3/2 beats per measure in each measure.  This acceleration goes on for two measures until the rate of the right hand is 7 beats/measure.  It takes 11 beats of the right hand to reach this new rate.

After reaching the new rate, the right hand stops accelerating and the two hands beat steadily, the left hand at 4 beats/measure; the right hand at 7 beats/measure.

Portfolio of edX style pre-class physics questions

MIT’s freshman physics class uses edX materials.  Among these was a sequence of “pre-class questions” and short articles intended to encourage students to read text materials and be aware of the basic features of the upcoming work that would be done in class.  The goal was to introduce basic ideas and vocabulary and to motivate rather than to assess consideration by students.

To view a portfolio of these physics pre-class materials

  • go to edge.edx.org; login as “guest@betterphysics.org” with the
  • password ‘guest’;
  • click ‘view course’; and
  • click on ‘courseware’ in the upper right corner of the screen.  There will appear
  • index of all the pre-class materials in reverse chronological order of their use in the course.
  • Click on any week and there will appear a sub-heading for the topics of that week;
  • click on any sub-heading and the material will be displayed.

John G. King (1925-2014)

Charles H. Holbrow
October 28, 2014

1 Introduction

“There is no substitute for hands-on fooling around with real stuff.” 1

John King’s death has taken from us someone who fervently believed this. But “fooling around” does no justice to his striking ability to see the physics in simple everyday things — the glug-glug of water pouring from a jug, the sound of tearing paper, the burn-out of a lightbulb — and his remarkable ability to imagine and construct ingenious apparatus for exploring that physics.

John King in 2004
Figure 1: John King in 2004 fooling around with real stuff. He is working on a corridor lab apparatus to measure the speed of light. By this time corridor labs were no longer used by the physics department, but John was helping MIT’s Edgerton Center build some corridor-lab boxes to engage and instruct people walking by the Edgerton Center. Photo by Ed Moriarty

This ability was manifest in all parts of his life whether setting up a generator system at his summer place in Maine, fixing the washing machine at home, devising a way to detect radiation emissions from a neighboring power plant, looking for a dipole moment of the electron or the spontaneous creation of protons, or generating microwaves with a spark-gap assembled from thumbtacks and a clothespin.

The pleasure and satisfaction that he got from devising simple apparatus to study everyday phenomena energized a life-long effort to get students, friends, colleagues, or passers-by to observe and explore the physical world around them. To him “hands-on fooling around with real stuff” was as natural as breathing. He wanted the rest of the world to learn to breathe as he did.

He did his “fooling around” with an acute understanding of physics and a remarkable detailed knowledge about how things are made, what they are made of, and how they work. “Things” included automobiles, motorcycles, laboratory instruments, electronic components, pumps, plumbing parts, and household hardware and appliances of all sorts. He particularly enjoyed solving laboratory problems with unexpected uses of equipment, as when he created a high-voltage pulse by briefly closing a circuit by firing a .22 bullet through a wedge of two angle irons mounted on a block of 2 x 4. A telephone book caught the bullet.2 Continue reading “John G. King (1925-2014)”

Use basic physics and engineering to design and build a working CCD camera

Dr. Zoran Ninkov, Professor in the Center for Imaging Science at Rochester Institute of Technology, described his year-long course in which his students learn and use basic physics and engineering to design and build a working CCD camera. For more information, see his A full-year university course sequence in Detector Array Theory, Camera Building, and System Testing..

Slides of his APS talk: