It started with a simple tweet. On Nov. 12, 2014, Robert Pattinson, the actor best known for his role as the young Lord Edgware in the movie “Goodbye Christopher Robin,” wrote: “Hope you’re having a great day. Thanks for the invite.”

Almost two years later, the 29-year-old actor is still actively engaging with fans on Twitter, using the platform to share various photos and funny stories about his time on set. Most recently, he’s been documenting the production of “The King,” his upcoming film about Albert Einstein, for which he’ll be playing the famous physicist.

While Einstein’s scientific achievements are well documented, his friendship with writer Kurt Wolff was less well known. According to biographer Kitty Kelley’s “Odd Man Out,” which was released in September, Wolff helped Einstein cope with the immense amount of fame that came with being one of the founding fathers of modern physics. But what exactly was their relationship like? And did it have anything to do with Einstein’s eventual discovery of his theory of relativity?

Einstein’s Relativity

The renowned physicist’s relationship with writer Kurt Wolff is often described as “tempestuous,” which is an appropriate adjective when describing their five-year collaboration. In fact, the two men’s professional and personal lives were so interwoven that one biography describes them as “virtually inseparable.”

In the autumn of 1905, after just two years of teaching at the tender age of 26, Einstein received a letter from an English publisher who wanted to meet with him about publishing a book. While he was flattered that anyone would take the time to write a book about him, the 26-year-old physicist felt that he had not yet accomplished enough in his field to be worthy of such a distinction. Still, he agreed to meet with the publisher provided he could keep working on the project during his down time.

That evening, after the publisher dropped off the check, they sat down together to begin working on the novel that would become “Relativity: The Life and Work of Albert Einstein.” A few months later, in January 1906, the first edition of Relativity was published, with Kurt Wolff credited as the sole author.

The book offered a candid and intimate look at the inner workings of the great scientist’s mind, filled with complex math and scientific theories that most readers would not have the patience for. Reviews were mostly positive, with Kirkus Reviews deeming it “[a]n important contribution to the literature of physics.” But a few reviewers had some complaints: Relativity was “so full of errors … it is difficult to decide which are more egregious, the errors or the biases” of the author.

A Friendship That Started on Twitter

Einstein and Kurt Wolff did not only work together on “Relativity,” they remained close friends even after the publication of the final edition in 1914. The two continued to correspond frequently, with some of their letters being published in Kitty Kelley’s “Odd Man Out,” which was published in September. One interesting fact that came out in this collection of letters is that they would often correspond about daily events, such as which restaurants they liked or what films were worth seeing. But they would also discuss deeper issues, including the concept of time and the philosophy of existence.

For example, in a letter dated Dec. 23, 1908, the two friends discussed timelessness

Kurt: I have always had the feeling, and this is what I have tried to convey in my book, that time is an essentially subjective phenomenon and that the fourth dimension, i.e., the timelessness of the Universe, is sometimes more difficult to grasp than the other dimensions. I sometimes wonder whether it was this very fact that caused certain problems for Einstein in the development of his theory of relativity. If time is not an objective fact but rather a subjective construction, then it is possible that an experiment might show that it does not exist. For instance, someone who travels back in time might find that the clocks have not worked correctly, or that the past is changed. But, of course, no objective time traveler has ever been invented, so this is a question that can only be answered by thinking.

Einstein: This is an interesting idea, and one that I cannot help but wonder about myself. That there might be a way to look at events that have already happened and see what comes next—that is the very essence of traveling to the future. Unfortunately, it is also the very essence of time travel that many of the science fiction novels and films that feature time travel are so very bad at science that the possibility of the technology being good never even crosses the mind of the characters.

Kurt: You see, Albert, I always suspected that you were a genius. You have proved me right. All your theories have been magnificent, and I am sure that the experiment you are planning to do will prove once and for all that time is but a convenient concept, albeit a very useful one.

E: Thanks, Kurt. I appreciate that. It is a great compliment, coming from such a great writer and philosopher as yourself.

Kurt: But, of course, you know that I love a good scifi novel as much as the next guy, but I do believe that you are taking the story too far. For instance, in your description of what happens in the experiment, there is too much science. You are applying an unjustified hierarchy of complexity to human thinking. You assume that the human brain can be directly compared to the mechanism of a planetarium, which is a terrifying idea. We are not machines. We are not supposed to be able to understand such complicated subjects like relativity and complex math. Besides, I detest relativity. It is an imperfect theory, and has some terrible contradictions and inaccuracies. If you want a more popular theory, I strongly recommend that you try out the quantum theory. It is much easier to understand, and it leads to much more satisfying conclusions.

E: Thanks, Kurt. It is nice to hear from you. I do appreciate your input. I think that you bring up some interesting points. For instance, the theory of relativity makes predictions that have been verified by experiment, so it is difficult to say that it is just a theory. But, at the same time, the idea that humans are not the center of the universe was once a theory, and is still considered to be unproven by many scientists. So, while I agree with you that the theory of relativity does have some limitations, it is also a beautiful theory that helps us to understand how things work at a fundamental level.