# RIP Daniel Kleppner (Physicist) **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [July 5, 2025, 6:19pm UTC](https://boards.straightdope.com/t/rip-daniel-kleppner-physicist/1020542 "2025-07-05T18:19:55Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [July 5, 2025, 6:19pm UTC](https://boards.straightdope.com/t/rip-daniel-kleppner-physicist/1020542/1 "2025-07-05T18:19:55Z")
He was co-founder and co-director of the MIT-Harvard Center for UltraCold Atoms; his work paved the way for making the first Bose-Einstein Condensate, and he won numerous awards. He was also co-author (with Robert Kolenkow of **An Introduction to Mechanics** , a book with a strict calculus-based approach to the topic and fiendishly difficult problems in it. It was the text for my first college class in physics and it made me realize how dumb I was. A couple of years later Kleppner himself was my professor for Advanced Mechanics, where I learned about Hamiltonians and Lagragians and other nonobvious mathematical methods. He also talked at length about the physics of meteorology, one of his pet interests at the time (although it’s not mentioned in his obituaries). Later still I was a Visiting Scientist at MIT. Although he had retired in 2003, he showed up at the group meetings. Fascinating guy. ---
**Author:** ![JWT\_Kottekoe](https://avatars.discourse-cdn.com/v4/letter/j/3ec8ea/32.png) [@JWT\_Kottekoe](https://boards.straightdope.com/u/JWT_Kottekoe)\ **Post date:** [July 5, 2025, 6:29pm UTC](https://boards.straightdope.com/t/rip-daniel-kleppner-physicist/1020542/2 "2025-07-05T18:29:59Z")
I was very sad to hear this. I never had him as a teacher, nor read any of his papers, but I knew him through committees we both served on. He was a wonderful man. ---
**Author:** ![Dr\_Paprika](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr_paprika/32/3042_2.png) [@Dr\_Paprika](https://boards.straightdope.com/u/Dr_Paprika)\ **Post date:** [July 6, 2025, 1:44pm UTC](https://boards.straightdope.com/t/rip-daniel-kleppner-physicist/1020542/3 "2025-07-06T13:44:23Z")
I don’t know the guy, but I did have a genius mechanics professor who insisted every fiendishly difficult problem be solved from first principles (which much improves analytical skills). His first year university engineering course, which a third of the class failed, did include Hamiltonians (a lot) and Lagrange (a little). Looking back, he touched on most of the engineering we learned over the next four years. I remember going to check my mark. I did well. He had a”sample copy” of the three exam questions posted on the wall, and it was ninety-two densely written pages. (You got full marks for reducing the answer to seven equations with seven unknowns). Sounds like quite a guy. I’ll have to check out his textbook. ---
**Author:** ![muldoonthief](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/muldoonthief/32/3188_2.png) [@muldoonthief](https://boards.straightdope.com/u/muldoonthief)\ **Post date:** [July 6, 2025, 1:52pm UTC](https://boards.straightdope.com/t/rip-daniel-kleppner-physicist/1020542/4 "2025-07-06T13:52:29Z")
> [@CalMeacham](#): > > He was also co-author (with Robert Kolenkow of **An Introduction to Mechanics** , a book with a strict calculus-based approach to the topic and fiendishly difficult problems in it. It was the text for my first college class in physics and it made me realize how dumb I was. QFT. That text really made me realize how little I learned in AP Physics in high school. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [July 7, 2025, 6:22pm UTC](https://boards.straightdope.com/t/rip-daniel-kleppner-physicist/1020542/5 "2025-07-07T18:22:33Z")
> [@CalMeacham](#): > > Although he had retired in 2003, he showed up at the group meetings. I’ve yet to meet any physicist who stopped working for a reason as silly as just that they’d retired. The year I left grad school, the most prolific member of the department was a professor who had retired over a decade prior. ---
**Author:** ![PastTense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pasttense/32/14550_2.png) [@PastTense](https://boards.straightdope.com/u/PastTense)\ **Post date:** [July 13, 2025, 1:50pm UTC](https://boards.straightdope.com/t/rip-daniel-kleppner-physicist/1020542/6 "2025-07-13T13:50:33Z")
> **[Daniel Kleppner, Physicist Who Brought Precision to GPS, Dies at 92](https://www.nytimes.com/2025/07/12/science/daniel-kleppner-dead.html)** > > He worked to develop an atomic clock that is essential to global positioning systems and helped confirm a rare state of matter predicted by Albert Einstein. Perhaps someone can provide a gift link? And a lengthy 2011 interview he did about his life’s work: > **[InfiniteMIT | Daniel Kleppner](https://infinite.mit.edu/video/daniel-kleppner)** > > The InfiniteMIT site is a collection of videos that create a vivid portrait of an institution that is continually changing the way we live and work. Interviews with legendary change-makers, historic footage from the MIT Museum collection,... ---
**Author:** ![Dr\_Paprika](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr_paprika/32/3042_2.png) [@Dr\_Paprika](https://boards.straightdope.com/u/Dr_Paprika)\ **Post date:** [July 13, 2025, 10:37pm UTC](https://boards.straightdope.com/t/rip-daniel-kleppner-physicist/1020542/7 "2025-07-13T22:37:49Z")
Gift link: > **[Daniel Kleppner, Physicist Who Brought Precision to GPS, Dies at 92](https://www.nytimes.com/2025/07/12/science/daniel-kleppner-dead.html?unlocked_article_code=1.WE8.-e1S.mEpOt640FgYy&smid=url-share)** > > He worked to develop an atomic clock that is essential to global positioning systems and helped confirm a rare state of matter predicted by Albert Einstein. ---
**Author:** ![JacobSwan](https://avatars.discourse-cdn.com/v4/letter/j/a6a055/32.png) [@JacobSwan](https://boards.straightdope.com/u/JacobSwan)\ **Post date:** [July 15, 2025, 1:29pm UTC](https://boards.straightdope.com/t/rip-daniel-kleppner-physicist/1020542/8 "2025-07-15T13:29:08Z")
> [@Chronos](#): > > I’ve yet to meet any physicist who stopped working for a reason as silly as just that they’d retired. The year I left grad school, the most prolific member of the department was a professor who had retired over a decade prior. My head of department retired at age 67 the year I graduated. He remained emeritus professor until his death 25 years later, just after his latest book was published He would attend faculty meetings at least once a week.About the only thing he retired from was teaching. That mechanics book is on a shelf behind me. I’ll flick through it later in memory of Daniel Kleppner. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [July 15, 2025, 1:33pm UTC](https://boards.straightdope.com/t/rip-daniel-kleppner-physicist/1020542/9 "2025-07-15T13:33:09Z")
> [@JacobSwan](#): > > That mechanics book is on a shelf behind me. I’ll flick through it later in memory of Daniel Kleppner. Try working one or two of the exercises at the end of a chapter. That’ll really remind you of what it was like.