NotesFAQContact Us
Search Tips
Peer reviewed Peer reviewed
Direct linkDirect link
ERIC Number: EJ860265
Record Type: Journal
Publication Date: 2008-Sep
Pages: 3
Abstractor: As Provided
Reference Count: 4
ISSN: ISSN-0031-921X
Torsional Oscillations and Waves Projected on the Wall
Bartlett, Albert A.
Physics Teacher, v46 n6 p338-340 Sep 2008
The article "Torsional Oscillations with Lorentz Force" by Paul Gluck provides a glimpse into the major world of ancient physics demonstrations in the late 19th and first half of the 20th centuries. The apparatus that was described and similar pieces of apparatus are the basis for many memorable but long forgotten educational demonstrations. The apparatus described was a small hairpin loop of wire whose long axis is perpendicular to a constant magnetic field. The loop carries an alternating current in a dc magnetic field, so the loop experiences rotational oscillations about the long axis of the hairpin. A tiny mirror cemented to the loop reflects a laser beam onto a distant wall, so when an alternating current is passed through the loop, the mirror oscillates and the reflected beam spot on the wall moves up and down. The following are just small glimpses of the wonderful physics demonstrations that the "ancients" developed, based on this wonderful device.
American Association of Physics Teachers. One Physics Ellipse, College Park, MD 20740. Tel: 301-209-3300; Fax: 301-209-0845; e-mail:; Web site:
Publication Type: Journal Articles; Reports - Descriptive
Education Level: N/A
Audience: Teachers
Language: English
Sponsor: N/A
Authoring Institution: N/A