University of Texas
David Theobald Blackstock
February 13, 1930–April 30, 2021

 

 

David T. Blackstock
(February 13, 1930-April 30, 2021)

 

Acoustical Society of America
Gold Medal Award
1993
David T. Blackstock

DAVID THEOBALD BLACKSTOCK was born in Austin, Texas, on 13 February 1930. The site of his home during high school is now occupied by the Mechanical Engineering Department building at the University of Texas at Austin, where David currently holds the position of Professor. He received B.S. and M.A. degrees in Physics from the University of Texas, after which he served as an Air Force officer at Wright Field in Ohio under the supervision of Henning von Gierke. While in Ohio, David met and married Marjorie Goodson. He later joined Ted Hunt's acoustics group at Harvard University, where he developed his interest in nonlinear acoustics. He received the Ph.D. in 1960 with a dissertation written under the supervision of William Raney (and typed by Marjorie, who said "never again"). David and Marjorie's first two children, Silas and Susan, were born in Boston, and their second two, Stephen and Peter, were born in Rochester, New York, where the family moved after David's graduation from Harvard.

David began his truly independent research in acoustics at General Dynamics/Electronics in Rochester, and after three years he joined the Electrical Engineering Department at the University of Rochester, where he was able to indulge his academic interests. A leave of absence spent at the University of Texas in 1969–70 led to a return home to Austin, with a subsequent appointment as Faculty Research Scientist at the Applied Research Laboratories. After many years teaching part time in the Mechanical Engineering Department, he became Professor in 1987. For the last five summers, David has returned to the cooler environs of the University of Rochester, where he works with Ed Carstensen and other colleagues at the Center for Biomedical Ultrasound.

The two individuals who are most often cited for their work in the 1960s on the fundamental theory of nonlinear acoustics are D. T. Blackstock in the United States and the late R. V. Khokhlov in the (former) Soviet Union. Working independently, Blackstock and Khokhlov established the foundation for modern approaches to the theory of nonlinear acoustics. David's main contribution during this period was the development of a consistent framework for existing models of finite amplitude sound. His framework incorporated the pioneering work by the 19th century physicists Poisson, Stokes, and Earnshaw, the Burgers equation for acoustics developed by Mendousse, Lighthill, and Khokhlov, and the weak shock theory constructed by Friedrichs, Landau, and Whitham. David investigated the connection between these earlier theories and showed how their solutions could be combined. He referred to his framework was a "low-amplitude nonlinear theory of simple waves," and his articles on the subject are frequently the first to be cited by subsequent authors writing about fundamental problems in nonlinear acoustics. Perhaps the defining achievement of David's approach was his proof that two well-known (and seemingly unrelated) solutions that were derived in the 1930s, one by Fubini for finite amplitude waves in the preshock region and another by Fay for sawtooth shock waves, are limiting cases of a single, more general solution for the propagation of finite amplitude sound.

At the University of Texas, David's theoretical models were tested by experiments performed by his students. The data they obtained on acoustic saturation, high-intensity sound beams, finite amplitude noise, N waves, and suppression of sound by sound now are regarded as reference data with which newly developed theories should be compared. To complement these experiments, computer codes were developed for modeling finite amplitude sound (the Pestorius and Anderson algorithms), and these have since been used in other laboratories around the world. Colleagues who influenced the experimental work in David's laboratory include Tom Muir, Allan Pierce, Izzy Rudnick, and Wayne Wright.

David's papers are known for their phenomenological insight and historical perspective. The terminology he introduced has frequently become standard in the field of nonlinear acoustics. Perhaps the most famous symbol he introduced has an ironic origin, however. In his seminal 1964 paper on solutions of Burgers' equation (not "Burger's equation," which is one of David's pet peeves), he discussed the critical importance of a dimensionless ratio of parameters that had been identified in the 1950s by Russian physicist Z. A. Gol'dberg. David labeled this ratio G, but the reviewer of his paper felt that such a label gave too much recognition to Gol'dberg and requested that the symbol be changed. David obliged by using the symbol Γ. But Γ is the first letter in the name Gol'dberg when written with the Cyrillic alphabet, so the published symbol still was appreciated by the Russian acoustics community. The symbol Γ now is used internationally to characterize the relative effects of viscosity and nonlinearity in a finite amplitude wave. Other (now common) symbols introduced by David include β (for the coefficient of nonlinearity), \sigma (used to characterize the extent of nonlinear distortion), and EXDB (for extra attenuation caused by finite amplitude effects). David thus is a scientist of considerable stature (for which he was elected to the Natl. Academy of Engineering in 1992), but that is not all.

As everyone who has heard David give a technical presentation knows, he is a gifted teacher with an insatiable curiosity. It is not unusual for David to ask a probing question of every single speaker in a technical session at a Society meeting. Nor is it uncommon for him to jump to a speaker's defense, particularly when the speaker is a student presenting a paper for the first time. David is passionately concerned with students, and his graduate courses at the University of Texas constitute a rite of passage within the acoustics program. The daily homework problems he assigns are characterized by novelty and relevance. Among the sources of inspiration for his problems are papers he hears at Society meetings. The solution of one of David's more challenging early problems (on explosion waves), one he believed to be sufficiently well understood to be suitable for a homework assignment, was later published independently by another researcher. Also, David's students learn to their chagrin that their homework is corrected for grammar as well as science, and that unsolicited observations may cost them points if they are incorrect. The theses and dissertations David supervises are models of clarity as well as technical excellence (usually not at first, but they are rewritten until they become so).

One place where David's students look forward to meeting him on equal footing is on the soccer field during lunch time. Perhaps it was after David corrected one to many dangling participles in a thesis draft that he found himself with a broken rib on one occasion, and required stitches on another, as the results of soccer matches with his students. After a few minor repairs, however, David was soon back on the field.

Finally, David is a true gentleman, and he is one of the most respected individuals within both the national and the international acoustics communities. David's stature in large part is due to his integrity, ethics, and concern for others, as is understood by anyone who knows him. He has chaired five ASA standing committees, and he was held every elected position through President of the ASA. He also has been a long-time member of three major international committees: he currently is the Chairman and the only U.S. member of the International Commission on Acoustics (which oversees the International Congresses on Acoustics); he is on the Organizing Committee for the International Symposia on Nonlinear Acoustics, and he serves on the U.S. National Liaison Committee to the International Union of Pure and Applied Physics.

Both the international acoustics community and the Acoustical Society of America long have benefitted from David's interest, dedication, and ability. It therefore is fitting that he be honored with the Gold Medal of the Acoustical Society of America.

Mack A. Breazeale
Mark F. Hamilton
Wayne M. Wright

Majorie Goodson Blackstock

OCTOBER 2, 1932 – DECEMBER 8, 2019

Marjorie Goodson Blackstock died at home in Austin, Texas, on December 8, 2019, surrounded by family members. She was born to Silas and Mary Goodson on October 2, 1932, in rural Clark County, Ohio, and grew up in Springfield, Ohio. She graduated from Springfield High School in 1950. In 1954 she graduated from Miami University (Ohio), where classes in Spanish began her lifelong love of the language.

While teaching at Fairborn High School near Dayton in the fall of 1954, she met (then 2d Lt) David Blackstock, a native Texan stationed at nearby Wright-Patterson AFB. They married June 19, 1955, and a year later moved to Watertown, Massachusetts, where son Silas and daughter Susan were born. Two more sons, Stephen and Peter, arrived during the 1960s when the family lived in Penfield, N.Y., a suburb of Rochester. The Penfield period was marked by strong neighborhood friendships and several cherished summer vacations at Oven Point on Long Lake in the Adirondacks. 

Soon after a 1969 move to David’s hometown of Austin, Marjorie began teaching in the Austin Independent School District, first as a substitute and then for 20 years as Spanish teacher at McCallum High School. She retired in 1993, having helped countless students prepare for college and taking some of them on trips to Mexico and Spain. She also accompanied David on many of his professional trips to England, France, Spain, Hawaii, and numerous cities in the continental United States.

After retirement, Marjorie became more active in the University Ladies Club, which she’d joined in 1970. She served as its president in 1998-99. In 2004-05 she was president of the UT Faculty Wives Club. Marjorie and David returned to Rochester, N.Y., for summers nearly every year from 1987 to 2016, reconnecting with dear friends and making new ones.

The 2005 celebration of their 50th anniversary, with 16 family members attending, was held in the Adirondacks. A subsequent family gathering in Colorado celebrated their 61st anniversary in 2016. Marjorie’s favorite activities included playing bridge with friends and swimming at Crenshaw Athletic Club. Medical problems limited Marjorie’s activities during her last two years, but she had a memorable last Thanksgiving with her husband, all of her children, and several grandchildren and great-grandchildren.

Marjorie was preceded in death by mother Mary Goodson (1988) father Silas Goodson (1995) and sister Joanne Binkley (2013). Survivors include husband David, son and daughter-in-law Silas Christopher and Brenda, daughter Susan Blackstock McAlpin, son and daughter-in-law Stephen Palmerand Tamara, son and daughter-in-law Peter Mathias and Lisa, six grandchildren, five great-grandchildren, and numerous cousins, nieces, and nephews.

 

David Blackstock died April 30, 2021. Here is his obituary from the Austin American-Statesman"

David Theobald Blackstock died at home in Austin, Texas, on April 30, 2021, in the care of family members and hospice. He was born to Leo and Harriet Blackstock on February 13, 1930, in Austin and grew up mostly in the Hyde Park neighborhood with his older brother Mathis. After graduating from Austin High School in 1948, David attended the University of Texas at Austin, where he earned BS and MS degrees in physics and was a member of the Silver Spurs. 

From 1954 to 1956, he served in the U.S. Air Force at Wright-Patterson AFB in Fairborn, Ohio. While there, he met Ohio native Marjorie Goodson. They married on June 19, 1955. The following year, David began graduate studies at Harvard University, earning his PhD in applied physics in 1960. While there, he made the first of what eventually became dozens of trips abroad to work with international researchers in his field. Son Silas and daughter Susan were born while Marjorie and David lived in Watertown, Massachusetts. 

After the Harvard years, the family moved to Rochester, New York, where David worked at General Dynamics/Electronics before becoming an associate professor in Electrical Engineering at the University of Rochester in 1963. Two more sons, Stephen and Peter, were born during the family's decade in the Rochester suburb of Penfield, where the family developed many lifelong friendships. David and Marjorie took joy in engaging their children with outdoor activities in upstate New York, including vacations to Oven Point in the Adirondacks, canoeing on the Genesee River and hiking at Mount Marcy.
 
In 1969, David returned to Austin for a sabbatical at UT. The temporary move became permanent when David accepted a faculty research scientist position at the UT-affiliated Applied Research Laboratories. He also began adjunct teaching in UT's Mechanical Engineering Department, helping to expand a small set of acoustics courses in the College of Engineering to the full-fledged program that exists today. 

David's home and work lives intersected in the 1970s when he began exploring Texas rivers on canoe trips that usually included family members and ARL colleagues. Day trips along Central Texas waterways such as the Guadalupe and San Marcos rivers eventually led to weeklong excursions in West Texas for trips down the Pecos River and the Rio Grande. Overseas research trips continued, with Marjorie sometimes accompanying him, including on a 1977 journey to Spain for the International Congress on Acoustics in Madrid. He took many photographs on both his professional and recreational journeys, leading to much-anticipated slideshow nights at home. 

Rigorously devoted to exercise and fitness, David began jogging in the 1970s, taking part in Austin's first few Capitol 10,000 races. He enjoyed playing soccer with colleagues on lunch breaks at ARL, also coaching little league baseball and youth soccer teams on which his sons played. Throughout the 1970s and '80s, the family frequently attended UT football games at Memorial Stadium, basketball games at Gregory Gym and the Erwin Center, and baseball games at Clark Field and Disch-Falk Field. 

In 1987, David became a professor in UT's Mechanical Engineering Department, taking an office in a campus building that ironically stood almost exactly on the site where one of his childhood homes had been. Empty nesters by then, David and Marjorie moved to the southwest Austin neighborhood of Lost Creek, where they lived for the next 16 years. They welcomed countless gatherings of family and friends to their home overlooking Barton Creek. Also in 1987, David reconnected with the University of Rochester, beginning three decades of summers spent teaching acoustics courses there. He and Marjorie renewed their 1960s Penfield friendships and made many new friends as well. 

Professional accomplishments and accolades began to accumulate during these fruitful autumn years. The Acoustical Society of America, for which David served as president in 1982-83, awarded him its silver medal in physical acoustics in 1985, followed by the gold medal in 1993. He was elected to the National Academy of Engineering in 1992. From 1990 to 1993 he was chair of the International Commission on Acoustics, which functions as a "united nations" for acoustical societies around the world. ARL honored him with its prestigious Jeffress Award in 1992, and the American Society of Engineering Education gave him its GE Senior Research Award in 1993. 

After editing the textbook "Nonlinear Acoustics" (1998, Academic Press) with longtime colleague Mark Hamilton, David authored "Fundamentals of Physical Acoustics" (2000, Wiley-Interscience), which remains a primary teaching text for acoustics classes. David "retired" in 2000, but he continued to teach two of UT's graduate acoustics courses for many years thereafter, and he continued working part-time at ARL throughout his 80s. The ASA awarded him its Rossing Prize in Acoustics Education in 2007, and in 2015 he received the Per Brüel Gold Medal for Noise Control and Acoustics from the American Society of Mechanical Engineers. Despite the international recognition these honors brought, David was most humbled when the ASA student council named its mentoring award after him in 2019. It is now called the Student Council David T. Blackstock Mentor Award. 

In 2003, David and Marjorie left Lost Creek and moved back to Northwest Hills, where they had many friends from their years living there in the 1970s-80s. They often hosted bridge games and other social functions for family and friends at the house. David and Marjorie celebrated their 50th anniversary with a family reunion in the Adirondacks in 2005, followed by a similar gathering in Colorado for their 61st anniversary. 

In 2016, David was diagnosed with an aggressive form of prostate cancer. He made many trips to M.D. Anderson in Houston to participate in trials for cancer treatments. Having transitioned from jogging to walking in his 70s, he continued to walk several miles nearly every day until he was 90. Marjorie's death from cancer in December 2019 and the social limitations caused by the coronavirus pandemic in 2020 took a toll on David's final year. Still, he continued walking with family members and supporting beloved local institutions such as KMFA and the Austin Symphony until his condition sharply deteriorated in January 2021. He entered home hospice in early February, with his children providing constant care and companionship in his final months.
 
David was preceded in death by mother Harriet Blackstock (1990), father Leo G. Blackstock (1972), stepmother Graham Blackstock (2006) and brother Mathis Blackstock (2012). Survivors include son and daughter-in-law Silas and Brenda, daughter Susan, son and daughter-in-law Stephen and Tamara, son and daughter-in-law Peter and Lisa, six grandchildren, five great-grandchildren, and numerous cousins, nieces and nephews. 

A memorial service is being planned for early summer; please check the obituary on the Weed-Corley-Fish Funeral Home website for updated information. In lieu of flowers, memorial donations may be made to UT's recently established David T. Blackstock Endowed Undergraduate Scholarship in Acoustics. Checks may be sent to Cockrell School of Engineering, Attn: Development Office, 301 E. Dean Keeton St., STOP C2104, Austin, TX 78712. For online donations: go to https://give.utexas.edu/?menu1=OGPEN** and choose Cockrell School of Engineering Area of Greatest Need, then the gift amount. Click on "Your Information," and in the gift comment section, enter "David T. Blackstock Endowed Undergraduate Scholarship in Acoustics."

In December of 2021, Stephen Blackstock, David's son, gave a 20-minute talk in a special session for his father at the Seattle meeting of Acoustical Society of America A link to the presentation is here: Stephen Blackstock Talk 

 

David T. Blackstock Photo and Document Album

David T. Blackstock, age 3, 1933

 

David T. Blackstock montage

 

David T. Blackstock and Otis Rhea Schmidt, "Bow and Gow" March 27, 1953, David and Rhea co-chaired the Roundup Parade Committee, which oversaw and administered the parade that was a major part of UT Roundup.

David T. Blackstock, officer, 1955 Wright-Patterson Air Force Base.

 

 

David T. Blackstock and Majorie Goodson Blackstock, June 19, 1955

 

David T. Blackstock and Majorie Goodson Blackstock, June 19, 1955

 

David T. Blackstock
David Blackstock with student.
David Blackstock
David Blackstock's Graduate Students

David and Marjorie Blackstock, Big Sur, 1990

 

David T. Blackstock and Majorie Goodson, 50th anniversary, 2005

 

David and Majorie Goodson Blackstock, 61st Anniversary, 2016

 

 

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