The Universal Timekeeper: Reconstructing History Atom by Atom

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Duration 01:08:30

Columbia University

David Helfand has been a Professor of Astronomy at Columbia University for 47 years, where he served as chair of the Department for two decades. He is also the former President of the American Astronomical Society and of Quest University Canada, and currently serves as Chair of the American Institute of Physics. Professor Helfand has received the Columbia Presidential Teaching Award and the Great Teacher Award from the Society of Columbia Graduates. He is the author of A Survival Guide to the Misinformation Age and, recently The Universal Timekeepers: Reconstructing History Atom by Atom.


By utilizing the basic building blocks of matter as imperturbable little clocks, we are now able to reconstruct in quantitative detail a remarkable range of human and natural events. From the discovery of art forgeries and the dating of prehistoric archeological drawings, to a detailed history of human diet and the Earth’s climate, to the events surrounding the death of the dinosaurs, the origin of the Solar System, and the history of the Universe itself, the universal timekeepers provide us with a precise chronology from the beginning of time to the moment humans emerge to contemplate such questions.




7 reviews
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Amazing Lecture!!!

David Helfand takes a most complicated subject and conveys what is understood about the age of the universe, earth, and human time on earth,
in the most interesting, entertaining, and knowledgeful way. Three cheers for
Professor Helfand. My awareness of my place in the universe is forever changed.

2 years ago
Gualdemar Gutierrez


Great explanation on the timing methods… Thanks

2 years ago
James Kreisle

Professor Halfant is not only a master in his field of astronomy and physics but also a brilliant teacher. In his articulate and well organized way, he makes complex things comprehensible, places them in their historical context and does so in a clever and entertaining way.

2 years ago
Virtryece Michel


I am so excited,I can’t wait to hear feel absorb his style of teaching.

2 years ago
Joy Morros

Love his lectures.

He has an amazing breath of knowledge. Thanks so much for trying to explain such a complicated subject.

2 years ago
marianne bernsen

clear and well organized and well spoken. I enjoyed this lecture and took from it what I could. Thank you.

Clear and well organized material- I enjoyed this lecture and took from it what I could! Glad to have heard it. Thank you.

2 years ago
kevin fox

Worth a dozen "Listenings"!

This is my second listening because (the last 80%) is so chock full of interesting information presented in memorable and visualizable fashion there’s easily a couple dozen “conversation pieces” presented in a way anyone can enjoy. (Theres nothing wrong with the first 20 % but it’s progressively less “background /common or high school level information” and progressively more “new to me” information). And despite the “crammed full” nature of the presentation the lecturer does wonderfully placing pauses for absorbing the many facts and many analogies offered to help visualize ( example if an atom were a marble a poppy seed would be 18 miles high ( or something like that – lol @ me)).

1 year ago
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