Happy 100th Anniversary to Einstein’s General Theory of Relativity!

relativity jacketToday is the final day of our popular #ThanksEinstein series, in which an array of prominent scholars and scientists have shared their insights and reflections on relativity, Einstein, and how his work inspired their own careers. Scroll through this week’s blog posts to read pieces by Daniel Kennefick, Katherine Freese, Hanoch Gutfreund, Jürgen Renn, Alice Calaprice, Jimena Canales, J.P. Ostriker, and many more special features, including this piece on Einstein’s final days.

Einstein’s General Theory of Relativity celebrates its 100 year anniversary today. November 25, 1915, during a particularly strenuous time in his life, is when Einstein submitted his final version of the general theory of relativity to the Prussian Royal Academy, complete with the field equations that define how the force of gravity arises from the curvature of space and time by matter and energy. The theory, which is the current theory of gravitation in modern physics, has implications for everything from black holes to the idea of universe expansion. It gained rapid popularity after its conception in 1915, and in the early 1920s alone, it was translated into ten languages. Fifteen editions in the original German appeared over the course of Einstein’s lifetime.

Princeton University Press has released a special edition of Relativity: The Special and the General Theory to commemorate the anniversary, including commentary from Hanoch Gutfreund and Jürgen Renn, Einstein experts, as well as additional content such as title pages from several language translations. You can browse through them in the slideshow below. Happy 100th to the general theory of relativity! Science wouldn’t be the same without you.

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Relativity Title Page, English Edition

Relativity Title Page, Chinese Edition

Relativity Cover, Chinese 1921 Edition

Relativity Cover, Czech Republic 1923 Edition

Relativity Cover, German Edition

Relativity Title Page, Japanese Edition

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#ThanksEinstein: J.P. Ostriker on Einstein and the wonder of pure thought

Einstein meme

Questions with No Reply

J. P. Ostriker

J.P. Ostriker is an astrophysicist and the co-author of Heart of Darkness, which tells the saga of humankind’s quest to unravel the deepest secrets of the universe: dark matter and dark energy. Here is his story about how an Einstein thought experiment he encountered as a teenager changed his life.

When I was a high school student I drove my teachers crazy with incessant and insatiable curiosity about the natural world. Next to our pictures in the yearbook, one of the teachers had added a line for each student and for me it was “I thought of questions that have no reply.”

And for the questions that I had that my teachers could not or would not answer, I went to books. Einstein wrote several of these that were accessible to high school students, and they fascinated me. I remember a “thought experiment” presented in one of them: A scientist sets up an exquisite laboratory on a train and tests both Newton’s laws of mechanics and Maxwell’s laws of electricity and magnetism. And, hypothetically, one finds that both are correct to arbitrary precision.

train image, copyright: phildaintThen the train begins to move and E shows that, since the laws transform differently with the velocity of the observer, they can no longer both be true! Therefore one (or both) theories must be false.

This amazed me. No experiment was necessary. Pure thought was all that was needed and any high school student who thought about it could have come to the same conclusion as Einstein, and could have invented special relativity to solve the problem! I thought that this was wonderful, truly wonderful. I resolved that I would pursue physics and think about simple and fundamental matters. It looked easy.

Well, needless to say it was not always easy, but it has always been fun. I’m thankful I had access to Einstein’s popular books when I was a teenager with more questions than answers.

Jeremiah P. Ostriker is professor of astrophysical sciences at Princeton University. He is author, with Simon Mitton, of Heart of Darkness: Unraveling the Mysteries of the Invisible Universe. His books include Formation of Structure in the Universe and Unsolved Problems in Astrophysics (Princeton).


Train tracks image from Shutterstock, copyright: phildaint

#ThanksEinstein: Katherine Freese on how relativity rejuvenated her career

Thanks Einstein Meme 3Under the Spell of Relativity

By Katherine Freese

Katherine Freese is director of Nordita, the Nordic Institute for Theoretical Physics, in Stockholm, and author of The Cosmic Cocktail, which tells of the epic quest to solve one of the most compelling enigmas of modern science—what is the universe made of? This is the story of how one of today’s foremost pioneers in the study of dark matter came back from the brink of burnout because of Relativity.

My career choice was hugely influenced by the work of Albert Einstein. I chose a career in physics precisely because I was inspired by his theories of relativity. My first exposure to physics was at Exeter Summer School in New Hampshire when I was fifteen years old. I went there after my junior year in high school because, frankly, I enjoyed learning and would otherwise have been bored over the long summer. I took an introductory course in physics and have to admit that, at first, I was a bit intimidated. But I got into it quickly and was gratified to discover that I did really well. The course was inspiring, and my teacher Mr. Dudley probably has no idea what an impact he had on me.

It was when the summer course turned to Special Relativity that I became really excited. What a bizarre and fascinating subject! To begin with, the idea that there is no absolute reference frame was an eye-opener. I later tried to explain this to friends, but they persisted in arguing that the Earth really does provide a special reference frame, world freeseat least for humans, so we should just compute everything from our own point of view.

Strange paradoxes arise when one makes one simple postulate, that the speed of light is the same in every reference frame. Two observers moving with relativistic speeds (relative to one another) measure completely different things. Clocks measure different times, and rulers measure different lengths. The shortest time is measured in the reference frame where the event takes place, and in every other frame time appears dilated. So an astronaut, who goes off into space and eventually returns, ages more slowly than the rest of us. There can be time travel! In the sense that the astronaut can come back to the Earth at an arbitrarily distant point in the future…if she can tolerate traveling at those speeds. Recently I met quite a few astronauts in Stockholm at the Congress of the Association of Space Explorers. They are amazing people. I was invited to give a 20 minute talk on “What we know about the Universe today.” A tall order in front of these folks. Can you guess what I talked about? Cosmology, beginning with Einstein’s relativity, of course.

These exciting things I learned when I was 15 made me determined to learn more physics, and I ended up majoring in physics in college. I went very young, at 16, and graduated with a bachelor’s degree in physics from Princeton University at the age of 20. It was really hard, I was burning out quickly, and at that point I wasn’t sure I wanted to continue. Chapter One of The Cosmic Cocktail, the book that was published by Princeton University Press just over a year ago, describes what happened next. I decided to take some time off from school. With my best friend, I went off to Tokyo to teach English and ended up serving drinks in bars for a giant salary. (I finally surpassed it a few years ago as a Full Professor.) A year and a half later, I went to Korea to renew my visa. While I was traveling around Pusang, my stomach, or so I thought, started to hurt. When I returned to Tokyo I was walking around doubled over with pain. Indeed it turned out to be appendicitis. I went to the Catholic Hospital, run by English nuns, and had my appendix removed.

While I was lying in the hospital bed, I read the only book I had brought with me, Spacetime Physics by Taylor and Wheeler. It is a book about Einstein’s special relativity. The book is beautifully written and only requires simple knowledge of forces, energy, and so on, and I loved it. The minute I got out of the hospital, I flew back to the US, reinvigorated by the desire to study physics. I contacted Columbia University, which had previously accepted me, and they let me in at a moment’s notice. I was lucky they did.

Einstein’s influence persisted. Two years into my graduate program at Columbia University, I went to Fermilab, the particle physics accelerator outside of Chicago, to work in experimental high energy physics. However, I also took a class in cosmology at the University of Chicago twice a week, out of curiosity. Plus, it took me into the city of Chicago. Fermilab is on a farm an hour west and has buffalo roaming around. The professor who taught the course, David Schramm, was a giant both physically and mentally, and one of the founders of the field of astroparticle physics, where the smallest particles explain the properties of the largest galaxies. We nicknamed him “Schrammbo.” (If you want to know more about him, you’ll have to read my book.) In that course, Einstein’s equations were applied to the Universe as a whole. Wow. I stopped showing up in the lab and instead sat in my housing at Fermilab and read about general relativity, this time at a graduate level framed by far deeper mathematics. Again, it was a turning point. I transferred to the University of Chicago to get my PhD with David Schramm in the field of cosmology.

In human history, every culture has had creation myths. In the past 100 years we have developed our own, the Big Bang. The difference is that the Hot Big Bang is right! The achievements over the past century in the field of cosmology are breakthroughs for all of mankind. We understand everything about our observable Universe all the way out to the farthest distant that light could have traveled to us in the age of the Universe (anything farther out could not have impacted us because the information could not travel in excess of the speed of light).

Now I’m a professional. I work with Einstein’s equations or their immediate consequences every day. I’m a theorist. I invent things and hope they turn out to match reality. All my work lies within the framework of modern cosmology, which began with Einstein’s work in relativity in 1915. What a brilliant man he was! Ever since I learned about relativity I’ve been under its spell, and I still am.

Katherine Freese is director of Nordita, the Nordic Institute for Theoretical Physics, in Stockholm, and professor of physics at the University of Michigan. She is the author of The Cosmic Cocktail.

#ThanksEinstein image courtesy of the official Albert Einstein Facebook page.

Washington Post highlights historic clash between Einstein and Bergson on the nature of time

2015_Einstein_bannerWith the 100th anniversary of the general theory of relativity coming up in November, Einstein is popping up everywhere. Yesterday’s Washington Post ran a terrific feature on Einstein books, including three of our own: Hanoch Gutfreund and Jürgen Renn’s The Road to Relativity, Einstein’s Relativity: The Special and the General Theory, and Jimena Canales’s The Physicist and the Philosopher.

One of the most fascinating chapters of Einstein’s public life revolves around an encounter he had with Henri Bergson, the renowned philosopher, on April 6, 1922, in Paris. It was on this day that Einstein and Bergson publicly debated the nature of time, touching off a clash of worldviews between science and the humanities that persists today. The philosopher Bergson argued that time was not merely mechanical, and should be seen in terms of lived experience; Einstein dismissed Bergson’s psychological notions as irreconcilable with the realities of physics. The Physicist and the Philosopher tells the remarkable story of how this explosive debate between two famous thinkers created intellectual rifts and revolutionized an entire generation’s understanding of time.

Nancy Szokan’s piece in Washington Post recounts the dramatic collision:

In The Physicist and the Philosopher, Canales recounts how Bergson challenged Einstein’s theories, arguing that time is not a fourth dimension definable by scientists but a ‘vital impulse,’ the source of creativity. It was an incendiary topic at the time, and it shaped a split between science and humanities that persisted for decades—though Einstein was generally seen as the winner and Bergson is all but forgotten.

Bergson and Einstein, toward the end of their lives, each reflected on his rival’s legacy and dedication to the pursuit of truth: Bergson during the Nazi occupation of Paris and Einstein in the wake of the first hydrogen bomb. Referencing Einstein’s quest for scientific truth, Hanoch Gutfreund recently had an article in the Huffington Post on how Einstein helped shape the Hebrew University of Jerusalem (home of the Albert Einstein Archives online):

On the occasion of the opening of the university, Albert Einstein published a manifesto “The Mission of our University”, which generated interest and excitement in the entire Jewish and academic worlds.

It states: “The opening of our Hebrew University on Mount Scopus, at Jerusalem, is an event which should not only fill us with just pride, but should also inspire us to serious reflection. … A University is a place where the universality of human spirit manifests itself. Science and investigation recognize as their aim the truth only.”

Read the rest here.

November’s big anniversary serves as a reminder of the enduring commitment to scientific investigation that continues at The Hebrew University and centers of learning all over the world today.

Read sample chapters of The Physicist and the Philosopher here, The Road to Relativity here, and Relativity here.

You can find information on the Digital Einstein Papers, an open access site for The Collected Papers of Albert Einstein, comprising more than 30,000 unique documents here.

To celebrate the 100th anniversary of Albert Einstein’s theory of general relativity, Princeton University Press launches books by Hanoch Gutfreund and Jürgen Renn

The Road to RelativityOn July 15th, Princeton University Press proudly launched two books by Professor Hanoch Gutfreund and Jürgen Renn, Relativity and The Road to Relativity, at the 14th Marcel Grossman meeting on relativistic physics in Rome.

The two books are being published to celebrate the 100th anniversary of Albert Einstein’s formulation of the theory of general relativity in 1915, and so it was fitting to launch them at a conference that demonstrates the ongoing influence of Einstein’s theory on cutting edge work on black holes, pulsars, quantum gravity, and other areas fundamental to our understanding of the universe.

The launch took place at the Besso Foundation, the family home of Albert Einstein’s friend and colleague, Michele Besso, during an exhibition, organized by Professor Gutfreund, of original Einstein letters and notebooks from the Albert Einstein Archives at the Hebrew University in Jerusalem.

relativity jacketMore than 150 distinguished physicists and invited guests, including the Chief Rabbi of Rome, Riccardo di Segni, and members of the Besso and Grossman families, listened to Professor Gutfreund and Professor Renn provide a compelling overview of their research and of the new insights it has brought to the history of the development of general relativity. Professor Gutfreund stressed the fundamental insights into Einstein’s work provided by the rich Archives in Jerusalem, while Renn dismissed the notion of Albert Einstein as an isolated and idiosyncratic genius, stressing his network of collaborators and colleagues, including Besso.


Renn and Gutfreund

Professor Hanoch Gutfreund and Jürgen Renn at the book launch in Rome

Photo from Renn and Gutfreund launch

Launch for Relativity and The Road to Relativity, at the 14th Marcel Grossman meeting on relativistic physics in Rome


Happy Birthday Albert Einstein

“Learn from yesterday, live for today, hope for tomorrow. The important thing is to not stop questioning.” – Albert Einstein

This is a huge year for Einstein at Princeton University Press. December marked the celebrated launch of The Digital Einstein Papers, a free open-access website that puts The Collected Papers of Albert Einstein online for the very first time. Today is Albert Einstein’s 136th birthday, as well as Pi Day, which, as Steven Strogatz writes in The New Yorker, is far “more than just some circle fixation.” So once you’ve rung it in with this Pi Day recipe, you might like to check out this book list in honor of the influential scientist and writer, who fittingly enough, shares his birthday with the popular mathematical holiday. Sample chapters for several Einstein related books are linked below.



The Meaning of Relativity:
Including the Relativistic Theory of the Non-Symmetric Field (Fifth Edition)

Fifth edition
Albert Einstein
With a new introduction by Brian Greene
Chapter 1

The Collected Papers of Albert Einstein, Volume 14:
The Berlin Years: Writings & Correspondence, April 1923–May 1925

Documentary edition
Albert Einstein
Edited by Diana Kormos Buchwald, József Illy, Ze’ev Rosenkranz, Tilman Sauer & Osik Moses

Chapter 1


bookjacket  The Road to Relativity:
The History and Meaning of Einstein’s “The Foundation of General Relativity” Featuring the Original Manuscript of Einstein’s Masterpiece

Hanoch Gutfreund & Jürgen Renn
With a foreword by John Stachel
Released April 2015


bookjacket The Physicist and the Philosopher:
Einstein, Bergson, and the Debate That Changed Our Understanding of Time

Jimena Canales
Released May 2015



Philosophy of Physics:
Space and Time

Tim Maudlin
Released May 2015Introduction



Einstein’s Real Breakthrough: Quantum Theory

Thank you to Yale University for recording this fantastic interview between A. Douglas Stone and Ramamurti Shankar.

People may be surprised to hear that Einstein could well be the father of quantum theory in addition to the father of relativity. In part this is because Einstein ultimately rejected quantum theory, but also because there is very little published evidence of his work. However, as he researched his new book Einstein and the Quantum: The Quest of the Valiant Swabian, Stone discovered letters and correspondence with other scientists that demonstrate the extent of Einstein’s influence in this area.

If you would like to learn more about Einstein’s contributions to quantum theory, grab a copy of Einstein and the Quantum which you can sample here.