On Albert Einstein's birthday: How Eddington and Einstein set an example for the international fellowship of science

The world woke up on the morning of November 7, 1919, to an amazing piece of news. A few months before in May, the English astronomer Arthur Eddington had led an expedition to the island of Principe off the west coast of Africa to try to observe one of the strangest phenomena ever predicted in the history of the science: the bending of starlight by the gravitational field of the sun. The phenomena could only be observed during a total solar eclipse, when the sun becomes dim enough to track the passage of starlight past it.

Eddington’s analysis proved that the light was bent by an amount that was twice that predicted by Isaac Newton, often considered the greatest scientist who ever lived. The man who trumped the great Sir Isaac’s prediction had until then been a relatively unknown forty-year-old physicist working in Berlin. His name was Albert Einstein, born on this day in 1879.

The observation of starlight bending was the first prediction of Einstein’s then otherworldly-seeming general theory of relativity: “One of the greatest achievements in the history of human thought. It is not the discovery of an outlying island but of a whole new continent of scientific ideas”, quipped the English physicist J. J. Thomson, discoverer of the electron. It was only the first among a stellar set of experimental observations that validated some mind-bending phenomena and ideas: spacetime curvature, black holes, gravitational waves, an expanding universe. It catapulted Einstein to world celebrity, and made him a household name and a part of the history books.

More importantly for the sake of world peace, however, it underscored one of the finest moments in the history of science diplomacy. The world had seen its first brutal world war end just a few months before, when the guns had finally been silenced in August.  The carnage had been unparalleled: more than 38 million casualties, with 17 million deaths. And in the light of this death and destruction, there was one country on which the world’s anger was focused: Germany. It seemed Germany had started the war and continued it, and it was fanatic German militarism that seemed to have sown the seeds of discontent.

In the middle of all that resentment then, it must not have gone unnoticed that an Englishman had confirmed a seminal prediction of a German’s reworkings of our understanding of the cosmos. In fact it was an exceptional gesture that would go down in history as a measure of the international brotherhood of science. Eddington, a pacifist Quaker who loathed war, joined heart and mind with Einstein, another pacifist who loathed war. At a time when the two countries had just come out of a horrific conflict with each other – a conflict streaked with memories of poison gas, trench warfare, dysentery and hand-to-hand combat - here was singular proof that there could be friendship between them again, that it was possible to forgive and move ahead together. The expedition at Principe confirmed a singular fact about science: that it can go beyond petty and deadly territorial disputes, that its bonds go deeper than those of rank or politics, and that, in the hands of men and women with conscience, it can rise above the fray and be the one shining candle in the dark. Einstein never forgot Eddington’s contribution to relativity and the hand of fellowship that bridged two nations who only a few months before had been sworn enemies. At the end of November, he finally gave in to the constant pleas from journalists and the public to hold forth on his theory and wrote a piece for the London Times on relativity. But he began the piece not with a scientific exposition but a human one:

“I gladly accede to the request of your colleague to write something for The Times [London] on relativity. After the lamentable breakdown of the old active intercourse between men of learning, I welcome this opportunity of expressing my feelings of joy and gratitude toward the astronomers and physicists of England. It is thoroughly in keeping with the great and proud traditions of scientific work in your country that eminent scientists should have spent much time and trouble, and your scientific institutions have spared no expense, to test the implications of a theory which was perfected and published during the war in the land of your enemies. Even though the investigation of the influence of the gravitational field of the sun on light rays is a purely objective matter, I cannot forbear to express my personal thanks to my English colleagues for their work; for without it I could hardly have lived to see the most important implication of my theory tested.” 

Einstein’s message here was clear. No matter what the political environment, science should trudge on, and political differences should not be a reason to squelch scientific collaboration. In fact such collaboration may be the only bond joining two countries together when all others have failed.

Eddington and Einstein’s plea for scientific fellowship has again become relevant, even as irrational nationalism has started to rear its ugly head, in the United States, in Europe and beyond. Demagogues with no understanding of science are trying to stem the flow of scientific talent from other countries, and no nation will be hurt more by this backward policy than the United States. More than any other single country, the United States has been the beneficiary of groundbreaking work by émigré scientists; in fact, the U.S. rose to scientific prominence when Jewish scientists fleeing from fascism in Europe migrated to its shores. It rose to world prominence in diverse scientific fields like astronomy, biomedical research and social science as these European immigrants and their students, along with others who came to the country during the last few decades from Asia, Africa, Australia and other continents, massively contributed to new scientific discoveries and inventions and won a string of Nobel Prizes.

If the United States starts appearing as an unwelcome destination for the world’s scientists, doctors and engineers, not only would this be a scientific disaster but it will be a human disaster. Immigrant scientists are often fleeing from persecution, broken economies and shoddy education standards and therefore usually work extra hard to ensure that their work brings success to their adopted countries. They may not all be Christians, but as is clear from the educational attainment and income levels of so many of these immigrant groups, they often live and breathe the Protestant work ethic of hard work, honesty and perseverance. As exemplified by a letter written by the German émigré Hans Bethe to his teacher Arnold Sommerfeld, many of them come to love their country and demonstrate deep loyalty toward it. Einstein himself was of course one of the most important examples of the immigrant experience in this country; when he moved to Princeton in 1933, the center of world physics moved with him. Alienating these people would not just be antithetical to the universal fellowship of science but it would decidedly not be in the United States’ best interests; it is these immigrant scientists and engineers who have started companies worth billions, discovered new drugs, materials and species, and contributed to America's tremendous supremacy in the information age. Supporting these immigrants is in fact putting ‘America First’.

One can have a perfectly reasonable discussion on limits to immigration without keeping talent away from these shores or without alienating potential immigrants who want to succeed in this country through hard work and family values. The current political environment has erased these important distinctions, if not explicitly at least in spirit, and it’s a distinction that we need to all clearly point out. The path ahead will not be easy, but as long as we support and understand each other, as long as we organize panel discussions and conferences and exchange programs which make people appreciate the international nature of science, we will move ahead together. All we need to do is have the Eddingtons and Einsteins among us keep finding each other.

"Understand what I love about America": Physicist Hans Bethe's moving letter to his teacher Arnold Sommerfeld

Hans Bethe, one of the true giants of twentieth century science, was also one of Adolf Hitler's greatest gifts to the United States. Fired from his position at the University of Tubingen in 1933 because of his Jewish ancestry, Bethe moved first to Britain and then, after an invitation from a former colleague, to Cornell University in 1935.

At Cornell he loyally stayed put for the next 70 years, establishing one of the world's great centers of physics. During this time he became one of the most prolific physicists in history, a true generalist contributing major insights to fields as diverse as nuclear physics, astrophysics and nuclear reactor analysis. He was a superb teacher, and counted both Richard Feynman and Freeman Dyson among his august students. He served as director of the theoretical physics division of the Manhattan Project at Los Alamos and then, after he midwifed the birth of one of humanity's most violent creations, spent the rest of his life tirelessly campaigning for its control and elimination. Bethe won the Nobel Prize in 1968 for figuring out one of science's greatest puzzles - the mechanism of energy generation in stars. He consulted for at least five presidents, served on many government committees and was actively working on supernovae when he died at age 99. He combined great scientific gifts with even greater human gifts; he was widely known as the conscience of the physics community.

Perhaps no other evidence exists of Bethe's indomitable leadership of science in the United States and his loyalty to this country than the letter he wrote to Arnold Sommerfeld. Sommerfeld was one of the greatest physics teachers of the century, and under his tutelage flourished such outstanding physicists as Bethe, Heisenberg, Pauli and Debye. Sommerfeld was very fond of Bethe, offering him a position in Munich after Bethe had been fired from Tubingen. He stayed in Germany during the war, trying to precariously hold on to German science under the onslaught of the Nazis so that it could be built up again after the war. One of the foremost ways in which he intended to do this was to try to bring back his former student Hans Bethe. To incentivize Bethe, Sommerfeld who by this time was close to retirement offered Bethe his own chair of physics at Munich. This was a very tempting and distinguished offer.

In response Bethe wrote what must be one of the most moving letters from one scientist to another, from a student to a teacher, and from one human being to another for that matter. It is worth copying out in its entirety because it showcases words like "loyalty", "affection" and yes, "patriotism" in their most genuine form. It also showcases American physics during one of its great ages and tells us what it was about the United States that made it so attractive to people from all around the world. The italics are mine.

20 May 1947 

Dear Sommerfeld, 

I am very gratified and very honored that you have thought of me as your successor. If everything since 1933 could be undone, I would be very happy to accept this offer. It would be lovely to return to the place where I learned physics from you, and learned to solve problems carefully. And where subsequently as your Assistent and as Privatdozent I had perhaps the most fruitful period of my life as a scientist. It would be lovely to try to continue your work and to teach the Munich students in the same sense as you have always done: With you one was certain to always hear of the latest developments in physics, and simultaneously learn mathematical exactness, which so many theoretical physicists neglect today. 

Unfortunately it is not possible to extinguish the last 14 years. . . . For us who were expelled from our positions in Germany, it is not possible to forget. 

Perhaps still more important than my negative memories of Germany, is my positive attitude toward America. It occurs to me (already since many years ago) that I am much more at home in America than I ever was in Germany. As if I was born in Germany only by mistake, and only came to my true homeland at 28. Americans (nearly all of them) are friendly, not stiff or reserved, nor have a brusque attitude as most Germans do. It is natural here to approach all other people in a friendly way. Professors and students relate in a comradely way without any artificially erected barrier. Scientific research is mostly cooperative, and one does not see competitive envy between researchers anywhere. Politically most professors and students are liberal and reflect about the world outside—that was a revelation to me, because in Germany it was customary to be reactionary (long before the Nazis) and to parrot the slogans of the German National ["Deutschnationaler"] party. In brief, I find it far more congenial to live with Americans than with my German "Volksgenossen." 

On top of that America has treated me very well. I came here under circumstances which did not permit me to be very choosy. In a very short time I had a full professorship, probably more quickly than I would have gotten it in Germany if Hitler had not come. Although a fairly recent immigrant, I was allowed to work and have a prominent position in military laboratories. Now, after the war, Cornell has built a large new nuclear physics laboratory essentially "around me." And two or three of the best American universities have made me tempting offers. 

I hardly need mention the material side, insofar as my own salary is concerned and also the equipment for the Institute. And I hope, dear Sommerfeld, that you will understand: Understand what I love in America and that I owe America much gratitude (disregarding the fact that I like it here). Understand, what shadows lie between myself and Germany. And most of all understand, that in spite of my "no" I am very grateful to you for thinking of me. 

Yours, 

Hans

Given Bethe's warm feelings for the United States and his immense contributions to its scientific community, national security and humane ambitions, it shouldn't be surprising to read the letter which President Lyndon Johnson wrote to him on occasion of his 60th birthday. The letter said:

"You are not only an outstanding scientist, you are also a devoted public servant. The nation has asked for your help many times and you have responded selflessly. You have made profound contributions in the fields of atomic energy, arms control and military technology. And you have been an important source of the immense contribution which science and the university community are making to society as a whole. Our country is deeply indebted to you."

During a time when words like "patriotism" inspire cynicism and are often being used as fig leaves for hiding ulterior motives, Bethe's letter should be required reading for those who have forgotten what this country stood for, how its ethos of openness and excellence attracted talented men and women from around the world, and how the people it welcomed with open arms became true patriots. As we simmer in an election season in which we seem to be awash in slogans rousing the emotions of the lowest common denominator, Hans Bethe's moving letter to his former teacher should hopefully remind us of the best that this country can offer.

Letter source (which saved me the trouble of typing it out): The original can be found in both Silvan Schweber's biography of Bethe titled "Nuclear Forces" as well as Schweber's superb contrasting study of Oppenheimer and Bethe, "In the Shadow of the Bomb."

Dear New York Times

You disappoint me

Dear Sir,
I was rather shocked to notice that in your "Notable Deaths of 2008" slide show that included 44 famous people from the arts, medicine, literature, television, politics, cinema, music and journalism, the name of the legendary physicist John Archibald Wheeler was missing. Dr. Wheeler who worked on the Manhattan Project died on April 13, 2008 and was one of the century's greatest scientists and a national treasure. During his long and remarkably productive life in which he worked with Albert Einstein and Niels Bohr, Dr. Wheeler played a key role in shaping American science, education and government policy. While it was heartening to see an obituary of him in the New York Times, I was quite disconcerted to see no mention of him in the Notable Deaths of 2008 Multimedia slide show list. While I understand that such an enumeration cannot be all-inclusive, Dr. Wheeler's stature as an American scientific icon should ensure the inclusion of his name in any short list of famous American people who died in 2008. I sincerely and strongly hope that this omission would be corrected.
Thanking you,
Sincerely,
Ashutosh S. Jogalekar
Atlanta, GA

Wheeler worked on the atomic and hydrogen bombs, served as an advisor to high-profile Presidential scientific committees, mentored brilliant scientists and leaders like Richard Feynman and Kip Thorne, resurrected and pioneered rather neglected relativity research in the 60s, coined the word "black hole", rendered invaluable teaching service at Princeton and Austin and propelled American physics into the first rank. If a list of notable American deaths of 2008 does not include his name, I don't know whose name it should.

When it comes to public exposition of achievement, it seems that popular media sources always give science short shrift in preference to other areas like art and cinema. The rift between the two cultures keeps growing. Science was undoubtedly one of the core foundations of The American Twentieth Century. Now it threatens to slip away from beneath the twenty-first. The country neglects it to its own perilous detriment. John Wheeler would have been unhappy.