This memorial website was created in the memory of our colleague and friend, Don Backer.  Please post your comments and stories here. 

The Donald C. Backer Memorial Fund has been set up at the University of California, Berkeley to honor him and insure that the science he pursued with relentless energy and passion will continue.  If you would like to donate to this fund, please go to

Posted by Namir Kassim on August 3, 2010
I was a grad student at Don's 1987 Galactic center meeting, where his warmth and support turned an otherwise intimidating experience into a fun and memorable one instead. Don remained an inspiration throughout my career, and I will sincerely miss him.
Posted by Paul Vanden Bout on August 3, 2010
Shocking and sad news. Don was an outstanding scientist and wonderful person. He will be sorely missed. Condolences to his family.
Posted by Athol Kemball on August 3, 2010
Don will be greatly missed - for his science, his vision and efforts on behalf of future instruments, and for his warm, engaging personal style. Condolences to his family and colleagues.
Posted by Alyssa Goodman on August 2, 2010
From our time in the 80's at Arecibo, up through his current statesman-like roles, I always admired Don's irreplaceable unusual combination of intelligence, humility and integrity. A lesson to us all
Posted by Jack Welch on August 2, 2010
Don was an outstanding scientist. Just as important, he was the kindest, most generous, and supportive person that I have known. I'll miss him for that. We all will.
Posted by Jeff Mangum on August 1, 2010
As an undergraduate astronomy major at Berkeley Don became my de-facto advisor. He introduced me to radio astronomy, which set me on a path that I continue to follow today. He will be greatly missed.
Posted by Maura McLaughlin on August 1, 2010
I admired Don as a brilliant scientist, but even more for his understanding, openness, gentleness, and lack of pretension. He was a wonderful mentor and friend to so many and he will be dearly missed.
Posted by Darrel Emerson on July 31, 2010
This was quite a shock. Don has been a good friend for many years, and will be missed in so many ways. Sincere condolences to all his family.
Posted by Justin Jonas on July 30, 2010
Without him knowing it, Don was one of my mentors from well before I actually met him - the scientist-engineer. I will always remember the bottle of red wine we shared in the Karoo.
Posted by John Dreher on July 30, 2010
Don was a great human being. He was generous of his time, even though the demand for his time was so high. He had a talent as a peace maker when things got contentious. Such a loss!
Posted by Al Wootten on July 30, 2010
This cams as a very great shock. Don exuded a great combination of cleverness and approachability. He was a wonderful friend and an inspiration. Please convey my sympathy to Susan and to Don's family.
Posted by Geoffrey Bower on July 29, 2010
Joeri van Leeuwen wrote a memorial for Don that has been posted with the ASTRON picture of the day:
Posted by Fred K. Y. Lo on July 29, 2010
I was scheduled to meet with Don at NRAO today (July 29) to discuss RSSP. Now, I will miss him, a good friend, a gentleman and a great scientist! My deepest condolences to Susan and David and family.
Posted by Steven Beckwith on July 29, 2010
Don was one of the great members of a great department, and he represented Berkeley as one of its finest diplomats, in addition to being a great scientist. He will be impossible to replace.
Posted by Jasper Horrell on July 29, 2010
With Don, an immediate connection. Full, quiet attention in that look. Many sensed it. Openness, warmth, humility, directness, truth and of course, the energy. Happy in the trenches! Travel well, Don
Posted by Michael Kramer on July 29, 2010
I am deeply shocked and saddened by this great loss. It is impossible to capture the impact and impression he left on people with his abilities, warmth and understanding with a few words. We miss him.
Posted by Robert L. Brown on July 29, 2010
My deepest sympathies to Susan and family, and to Don's colleagues at Berkeley and around the world. His life touched us all; he enriched us all.
Posted by Tom Bania on July 29, 2010
I met Don when I came to Charlottesville in 1971. Through the years we had many a pleasant conversation about Life, The Universe, & Everything. I will miss him. Condolences to
his family.
Posted by Anthony Readhead on July 29, 2010
I am deeply shocked, having known Don for over thirty years, since we first worked on VLBI together. It was always enjoyable working with Don. A great loss, both scientifically and personally.
Posted by Maureen Barnato on July 29, 2010
In his quiet and thoughtful way, Don always brought the humanity factor to decision-making.  I think he was unique in that regard...
Posted by Alan Rogers on July 29, 2010
I remember with great pleasure working with Don on VLBI at millimeter wavelengths. Don was a wonderful guy as well as a great astronomer and engineer and will be remembered by all.
Posted by Craig Nordlie on July 29, 2010
We all are deeply saddened by the passing of Don. His Air Force admirers send the family their very best
Posted by Tom Pierson on July 29, 2010
The gaping hole left by Don's passing is difficult to comprehend. He was such a fine and gentle man, yet a giant in his field. I will sorely miss Don, and send my warmest condolences to his family.
Posted by Jonathan Marr on July 29, 2010
In his quiet and unassuming way, Don was a special advisor for me who made me comfortable in my work with him. He always gave his full attention and respected others’ opinions. He'll be missed.
Posted by David Nice on July 29, 2010
Don's death is a shocking loss to the pulsar community. His engineering skill, scientific ability, energy, enthusiasm, leadership, goodwill, and friendship will be greatly missed.
Posted by B H on July 28, 2010
Posted by B H on July 28, 2010
We are collecting photos of Don. Please send them to Barb Hoversten at
Posted by Aaron Parsons on July 28, 2010
Posted by Michael Strauss on July 28, 2010
I was deeply saddened to hear of Don's death. I have known him since the 1980's; he was a great scientist, a man of great integrity, and a genuinely nice and humble guy.
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Recent Tributes
Posted by Casey Law on July 27, 2020
I continue to acknowledge Don's contribution to my research and the way I conduct my research. I wouldn't be where I am today without his patient and kind support during my time at UCB.
Posted by Geoffrey Marcy on July 25, 2020
Don - We miss you more than ever. The entire world needs your love of community, communication, and shared humanity. I am still learning from you.
Posted by Jill Tarter on July 25, 2020
It is hard to believe that we've been without your guidance and friendship for 10 years. I think you would be pleased with the continued progress in the projects you helped launch - HERA and the ATA.
Recent stories

Two Memorable Green Bank experiments

Shared by Tom Bania on July 25, 2011

I first met Don in 1971, my first year of grad school at UVa and he was on his NRAO PostDoc.
He was always willing to chat and support a callow grad student.

I remember two experiments he did over the years in Green Bank with especial awe because, as usual for Don,
he used equipment in extremely novel ways.

In the early 1970s he followed *individual* pulsar pulses in frequency by using all 5 GB telescope independently
tuned to different frequencies (the 140 ft, the 300 ft, and the 3 85 ft interferometer elements).  This required
writing a complete operating system for the interferometer which had never at that point been used as
individual telescopes tuned to different frequencies.

In the mid 1980s he studied giant pulses from the Crab -- these things are 103 stronger than the mean pulse
intensity but are both infrequent, say, 1/5000, and sporadic.  His pulsar back end in GB had finite bandwidth of
course and, in those days, finite storage capacity.  So he couldn't just crank away and observe continuously.
His solution was to team with Tim Hankins who observed the Crab at L band at the VLA which had a mode
where they could observe constantly albeit at low resolution.  When Tim found a giant pulse, he sent a
trigger signal to Don at the 140 ft *over the Internet* so he could turn on his pulsar backend to sample
at 800 MHz with 85-2.  To make this work they had to synch the clocks of
their computers for days, again over the internet, taking out packet speed fluctuations by polling many,
many different clocks around the internet.  At least that is what I recall.

As Jim Moran said in Physics Today, we are all much poorer now from the loss of his humanity as well as his technical gifts.

Field trip!

Shared by Nina Ruymaker on September 24, 2010

i had been working for the Astronomy Department only a short while, when Don thought it would be a good idea to take the new hires up to Hat Creek Radio Observatory for a look around & to meet the staff there. I jumped at the opportunity to leave town; what could be better than to be in Mount Lassen country? Don, Robert, Andrea, & I met in the early hours downtown Berkeley & headed north. Once there, we had a staff meeting & now were able to put a face to the names of people we had been working with via telephone/email.  Susie & Don took us around in the Jeep & gave us the grand tour, Don trying his best to explain in layman terms just what was going on up there; yep, a little hot & arid, but beautiful country all around. Susie advised checking out Burney Falls, where we took a hike and considered jumping in the lake nearby. We luxuriated in our surroundings; exploring the lava tubes, taking beautiful moonlit bicycle rides in the middle of the night.On our way back home, we tried to climb Mt. Lassen, but being a little unprepared - such as trying to scramble up steep icy inclines in tennis shoes - proved to be too much, so we had to, most unwillingly, let it go...I still find it very difficult that someone so vital and engaged with life and those around him could be so suddenly gone from us. I will miss him, more than I can say.

nina ruymaker 



Goodbye, Don

Shared by Geoffrey Marcy on August 7, 2010

 In the past 5 years, I attended "executive Dept meetings" weekly with Don, while he was Chair of the Astronomy Dept. and then when he was the Director of RAL.    Of all the discussions, visions, budget troubles, restructuring, struggles, and conflicts that arose in those meetings, one thing stands out far above everything else.   Don was always finding ways to improve the communication, coherence, and collegiality of the astronomers in Berkeley.  

He always had a new organization in mind that would join everyone together to makes us  more than the sum of our parts.  "BACI" was the name of his beloved organization that brought Berkeley Astrophysics together.   He loved the idea that if people worked together they would be more creative and productive, and enjoy their work more.    He appreciated that people working together, rather than separately, was the key to unexpected innovation.    

He similarly took the Department's decadal Academic Review to heart, spending countless hours constructing that document, always involvilng everyone in the process.   He similarly encouraged  a diverse but coherent group of radio lab, digital electronics, and radio telescope design efforts, always thinking that some FPGA-type or DSP-type widget would emerge when folks with different expertise interacted.    And the new Campbell Hall project brought all of this together as Don constantly encouraged the architects to design interactive areas for astronomers to chat and bridges to allow cross-fertilization with physics.   Collegiality and interaction were dear to Don.   I've learned a lot from his patience, kindness and people-oriented science.