It appears that Albert Einstein, while working to explode humanity’s understanding of the universe and space-time, was also breaking hearts at a relatively speedy rate. This week, the Princeton University Press and Hebrew University of Jerusalem made public the Digital Einstein Papers, a collection of the Nobel Prize winner’s papers, notebooks and essays -- as well as his personal letters with his first first wife, Mileva, and his cousin-turned-lover-turned-wife, Elsa, among others.

The correspondences are organized chronologically and give a candid view of the father of relativity’s divorce from Mileva -- with whom he had two children and a very rocky marriage -- in 1919, by way of both his letters to her and his concurrent letters to Elsa.

After years of marital conflict, Albert and Mileva relocated from Switzerland to Berlin. Prior to the formal divorce, Einstein, already in love with Elsa, stonily proposes these terms to his wife, should he not divorce her:

"A. You Make Sure

  1. That my clothes and laundry are kept in good order and repair.

  2. That I receive my three meals regularly in my room.

  3. That my bedroom and office are always kept neat, in particular, that the desk is available to me alone.

B. You renounce all personal relations with me as far as maintaining them is not absolutely required for social reasons. Specifically, you do without

  1. My sitting at home with you.

  2. My going out or traveling together with you.

C. In your relations with me you commit yourself explicitly to adhering to the following points:

  1. You are neither to expect intimacy from me nor to reproach me in any way.

  2. You must desist immediately from addressing me if I request it.

  3. You must leave my bedroom or office immediately without protest if I so request.

D. You commit yourself not to disparage me either in word or in deed in front of my children."

After this straightforward and seemingly frosty contract, Einstein closes the letter, "I am ash[amed] for you because you let yourself be so affected by Berlin. ... Go your own way, let yourself be deceived. I really don’t care. Read this slowly. It will do you good. Read it also to your family, they have nothing else to do."

It would seem Mileva wasn’t interested in living apart together nor with disappearing without a fight. Einstein, for his part, is immovable in his convictions, stern and more than a little unfeeling.

"What remains of my confidence in you is just enough for a business relationship. It remains possible that I’ll regain a greater degree of confidence in you through proper behavior on your part. Let it be as he wishes. No one can see into the future. In any case, I don’t consider discussions about it useful. Therefore I ask you again whether you want to live with me under the specified terms," Einstein writes to Mileva.

About a week later, Einstein tenderly writes to Elsa, presumably in another city for the time being, to update her on the situation. "The way to divorce has also been smoothed. Now you have proof that I can make a sacrifice for you. What you have suffered in the last few days has made such an impression on me that I couldn’t act in any other way, despite the children," he write.

But leaving his wife and children for his cousin-lover was not without its emotional tolls:

"... I must admit I feel a bit crushed; do you understand? Some time will have to elapse before I am again calmly in possession of myself. Such an affair is bit similar to a murder! But I came to realize that living together with the children is no blessing if the woman stands in the way. Tomorrow they will probably leave; I hope I’ll be able to see my boys one more time!

Moving on ...

After the meeting at Haber’s, I drove to your parents, who didn’t come home until after 11 o’clock, though, and received the news not without a mild distaste."

A note: Elsa’s parents were Einstein’s uncle and aunt. And then ...

"Tonight I’m sleeping in your bed! It is peculiar how confusedly sentimental one is. It is just a bed like any other, as though you had not yet ever slept in it. And yet I find it comforting that I may lay myself in it, somewhat, like a tender confidence."

He closes the letter sweetly:

"Kisses from your

Albert."

A few days later, Mileva and the children departed from Berlin. From this point on, all communications with his ex-wife are curt but polite notes about Einstein’s alimony payments. "The last battle has been fought. Yesterday my wife left for good with the children. I was at the railway station and gave them a last kiss. I cried yesterday, bawled like a little boy yesterday afternoon and yesterday evening after they had gone," Einstein writes to Elsa.

But the end wasn’t without a fight, "Yesterday morning I spoke with her for the first time; we parted rancorously. She perceived my conduct as a crime against her and the children. ... I know my wife well enough to know that with her characteristic consistency she will erect a wall between me and the boys similar to the one she had attempted to build between me and my family," Einstein writes of a meeting with Mileva.

While the departure of his children clearly upset him, Einstein wasn’t averse to moving on:

"You, d[ear] little Elsa, will now become my wife and become convinced that it is not at all so hard to live by my side. I know that you are capable of it. After so many years you will again be able to govern and manage the house freely, and all the little people will do you honor."

And with that, Einstein’s first marriage was over, paving the way to a marriage with Elsa that would last until she died in 1936. A monogamous union it was not, however: Einstein, with Elsa’s permission, hired his mistress as his secretary for a few years. However, any letters regarding this and Einstein’s later love life have yet to be added to the collection, which so far covers only through 1923 in 13 of a planned 30 volumes. (Einstein died in 1955.)

Einstein faced media scrutiny both during his divorce and after. However, in an earlier letter to Marie Curie, addressing the scandal surrounding her and her lover, physicist Paul Langevin, he made his position on the haters clear:

"Highly esteemed Mrs. Curie,

Do not laugh at me for writing you without having anything sensible to say. But I am so enraged by the base manner in which the public is presently daring to concern itself with you that I absolutely must give vent to this feeling. ... If the rabble continues to occupy itself with you, then simply don’t read that hogwash, but rather leave it to the reptile for whom it has been fabricated.

With most amicable regards to you, Langevin and [physicist Jean Baptiste] Perrin, yours very truly,"

And finally, because he is Einstein:

"P.S. I have determined the statistical law of motion of the diatomic molecule in Planck’s radiation field by means of a comical witticism, naturally under the constraint that the structure’s motion follows the laws of standard mechanics. My hope that this law is valid in reality is very small, though."

His hope for love, it seems, was much larger.