Sounds good!

Logo of the Acoustical Society of America. ASA is one of our member societies. The author does not wish to play favorites but notes that they are pretty cool.

As a librarian, I have a responsibility to all of our materials. We prioritize our collection development policy, underrepresented voices in the history of physics, and the needs of our researchers when considering collection development (choosing which books to receive as donations or to buy).  Sometimes, I have to admit that those needs might also be fairly remote from my own sphere of knowledge. However, as any of my colleagues will tell you, information professionals tend to gain knowledge and interest in whatever is in our collections. One thing I love about my job is that it exposes me to worlds of information that I would never have encountered otherwise. As such, I’ve gained appreciation for areas of physics and history that I had not paid much thought to before starting my job at NBLA. Even though I think it would be awesome, it is indeed a good thing that all libraries are not filled with things that I know and care about (though perhaps one day I will go on to open a pinniped/flute/music/baking/Norwegian/children’s illustration/mushrooms/fashion library, and I think that might pretty awesome). 

This being said, if someone were to ask my opinion about subject areas within our collections, I do have a favorite branch of physics: acoustics. As a musician, it’s the area of physics that I feel makes the most sense, the area that I can see practical applications for in my own life, and the area where I might encounter ideas and meet people who are also obsessed with music and sounds. Whenever I get to interact with materials in our collections that focus on acoustics, I always get excited. 

Lindsay’s Wheel of Acoustics. Though musical and architectural concepts are what many associate with the word “acoustics,” it is a surprisingly wide field, with applications in medicine, physiology, psychology, speech, visual arts, mechanical engineering, electrical engineering, chemical engineering, oceanography, and the physics of the Earth and atmosphere. Credit: R. Bruce Lindsay, Creative Commons License

Therefore, indulge me for this Photos of the Month, devoted to photos in our Emilio Segrè Visual Archives that relate to the branch of physics concerned with the properties of sound. 

Harvey E. White demonstration of chladni sand figures from a lesson on sounds from musical instruments. Credit: AIP Emilio Segrè Visual Archives, Physics Today Collection, Catalog ID: White Harvey F4

Harvey Elliott White (1902-1988) was an American physicist who led a long career that included a Guggenheim Fellowship for the spectroscopic study of gasses in a Hawaiian volcano and a successful bout of instructional television for the public. Here, he is demonstrating chladni sand figures for a lesson on sounds from musical instruments. Chladni plates are metal plates with a speaker attached, and they work by putting sand on the plate, and then playing various tones on the speaker. Different patterns will form based on the pitch of the sounds played. According to the Smithsonian, “Violin makers have long used Chladni figures to provide feedback as they shape the critical front and back plates of the instrument’s resonance box.”

To see an awesome use of chladni sand plates, check out this music video, based on physics experiments (creator Nigel Stanford explains those experiments in a blog post here). The sand plate appears at the 14 second mark.

If you’d like to make your own Chladni plate, the Society of Physics students has instructions here.

Vivian Leroy Chrisler, of the Bureau of Standards, sits in a box in the sound laboratory. Credit: AIP Emilio Segrè Visual Archives, Catalog ID Chrisler Vivian Leroy D1

In this image, Vivian Leroy Chrisler, of the Bureau of Standards, sits in a box in a sound laboratory while studying the echo-producing properties of conditions found in talking picture theaters. The box prevents his clothing from intervening with the tests; note that the “audience” sits in typical movie theater seats.

Bell Labs Sound Experiments: double dome research with Oscar II. Credit for both images: Bell Laboratories / Alcatel-Lucent USA Inc., courtesy AIP Emilio Segrè Visual Archives, Physics Today Collection. Left Catalog ID: Bell Labs F4, Right Catalog ID: Bell Labs F3 

I will let the caption on these photos do the explaining.

"Two heads are better than one for Bell Telephone Laboratories research into the ways people locate the direction of sound. Practical results of the recent 'double dome' research at Murray Hill, NJ, may be the improvement of stereophonic radio and TV programs, which are transmitted nationwide over telephone facilities. In the experiments, two microphones in the ears of the dummy, 'Oscar II' were substituted for human ears. Oscar's head reproduced the 'shadowing' of sound by a human head. Persons participating in the tests -- such as Mary Lou Hartig, shown -- wore the extra head so that motions of their heads would be reproduced, for even very small movements influence hearing. The natural sounds received in each microphone were altered electronically by acoustics scientist, R. L. Hanson (right) and were delivered to the earphones. Listeners were asked to point to the apparent direction of the altered sound. Normally, the ear that is closer to a sound hears it earlier and louder than the other ear. Here, however, artificial differences in time delays and intensity were introduced, and it was found that the factor of intensity is more important than previously believed. If sound reaches one ear first but reaches the other ear somewhat louder, the hearer is completely confused."

Thomas Greenslade with equipment. Credit: AIP Emilio Segrè Visual Archives, Gift of Thomas B. Greenslade, Jr., Catalog ID Greenslade Thomas F1

Thomas B. Greenslade, Jr. at the age of 16 working on a science fair project for the spring of 1954. Greenslade won first prize at the Staten Island science fair by transmitting music on a light beam. Photo taken by Greenslade's father, Thomas B. Greenslade, Sr., in the basement of their Staten Island, NY home. He is now Professor Emeritus of Physics at Kenyon College, Gambier, Ohio. Given his early proclivity for tinkering, it is perhaps unsurprising that Professor Greenslade keeps a website detailing historical physics apparatus called Instruments for Natural Philosophy, including many acoustical instruments, and has written a Physics Today article: Adventures with historical physics apparatus.

Portrait of Ilene Busch-Vishniac standing outdoors. Credit: AIP Emilio Segrè Visual Archives, Gallery of Member Society Presidents, Catalog ID: Busch-Vishniac Ilene A1

Though she started as a music student, playing piano and thinking about a career in music therapy, Ilene J. Busch-Vishniac ended up in acoustics and made major advances in the theory and understanding of electret microphones. The electret microphone is the basis for 90 percent of all microphones used today. She has also patented several new designs. She served as President of the Acoustical Society of America from 2003-2004. Read an interview with her in Acoustics Today here.

Informal portrait of James West. Credit: AIP Emilio Segrè Visual Archives Gift of Dr. West, Catalog ID: West James B1

Informal portrait of James West, co-inventor of the foil electret microphone, and Acoustical Society of America (ASA) president from 1998 - 1999, with acoustic equipment. West developed this important condenser microphone with his research partner Gerhard Sessler in 1962. West and Busch-Vishniac, from the last image, have collaborated quite a bit throughout their careers, including on a project to reduce the (then) understudied problem of noise in hospitals, current research with respiratory devices, and many publications. Now a professor of electrical and computer engineering and mechanical engineering at Johns Hopkins University, West’s career highlights include 40 years at Bell Labs, 60 US patents and over 200 foreign patents, current efforts to improve teleconferencing technology, and mentorship to many students.

Eugene I. Gordon, left, and Conway LeCraw, right. Credit: Bell Laboratories / Alcatel-Lucent USA Inc., courtesy AIP Emilio Segrè Visual Archives, Hecht Collection, Catalog ID: Gordon Eugene F3

Eugene I. Gordon (left), and Conway LeCraw discuss properties of yttrium iron garnet (YIG), using a model of the unit cell of a YIG crystal. LeCraw is holding a YIG sphere used in measurements of the material's acoustic properties at Bell Telephone Laboratories. YIG is a synthetic garnet with properties that make it useful for magneto optical imaging applications in superconductors.

Hideki Yukawa. Credit: AIP Emilio Segrè Visual Archives, Yukawa Collection, Catalog ID: Yukawa Hideki B5

Hideki Yukawa in Osaka, seated, singing traditional Japanese music. Yukawa became Japan’s first Nobel Laureate in 1949 based on his prediction of the pion. ESVA holds many images of physicists making music; the Photos of the Month in May 2016 was all about physicists as musicians.