An Irishman's Diary

Seventy-three years ago this week, on the Winter Solstice of 1939, a man named Ludwig Hopf died in Dublin. German-born, he had been a professor of mathematics in Trinity College. And, as almost goes without saying, he was a recent arrival in Ireland.

Hopf previously worked in Aachen until forced to flee the Nazis. He got out just in time, joining an exodus of Jewish scientists that scattered across Europe in the late 1930s. He went to Cambridge first. Then, with his wife Alice and three children in tow, he found refuge in a country that, via Éamon de Valera, had a maths enthusiast as taoiseach.

But the shadow of war followed them even to Ireland. Hopf’s son Arnold had been less lucky than his father. Planning to emigrate to Kenya, he delayed long enough to be incarcerated in Buchenwald. Although he later escaped, and made it to Africa in the end, the stresses on the family probably hastened the professor’s demise. He died only months after taking up the Trinity post, aged 55.

Among those who paid tribute at his graveside was Erwin Schrödinger, himself recently arrived in Dublin to head up de Valera’s Institute for Advanced Studies. Schrödinger called Hopf “a friend of the greatest geniuses of his time”. Then he added: “Indeed, he was one of them”.

This was no exaggeration. Hopf had been both friend and collaborator of the era’s greatest genius, Einstein, with whom he worked in Zurich and Prague. They wrote papers together. And perhaps just as impressively, they played musical duets.

His professional achievements aside, Einstein was a talented violinist who, when engaged in deep thinking about a question of physics, often took time out to play music, while his subconscious got on with the problem.

Thus the fact that Hopf was an excellent pianist also recommended him as a colleague. The two men’s joint contributions to physics include the Einstein-Hopf Drag. Sadly, their musical collaborations are unrecorded.

Her husband’s death was not the only bereavement Alice Hopf suffered in Dublin. Their daughter Liselore died three years later, aged only 19, and was buried in the same grave. After that, Alice and the other children went to live in England and the Irish link was lost.

Locating graves

Several decades later, in the 1970s, a Wicklow-born priest called Willie Walshe was dispatched to Kenya on missionary work. He found himself based in Kitale: a poor town in the country’s western Rift Valley Province. Like many parts of Kenya, this was home to some very talented runners.

But as Fr Walshe discovered, its residents also included a German expatriate named Arnold Hopf. A magistrate in the old colonial service, Hopf had settled in Kenya and, although Jewish himself, had married a local Catholic, who along with their children, was part of Walshe’s congregation.

Hopf was well known in the area. He often passed the priest’s house on the way into town to buy groceries and also regularly stopped for a beer in a bar called the Bongo. But he never spoke about Buchenwald or about the Holocaust in general.

Two fellow prisoners who made the attempt with him were shot. And despite his escape, the camp experience left a mark on him too. He retained a life-long aversion to confined spaces, never closing the door of any room he was in. Even during his final illness, he refused to go to hospital.

Hopf Jnr had not attended his father’s funeral, nor his sister’s. Indeed, he had never been to Ireland. But his papers included a moving letter from his mother – now in Fr Walshe’s possession – written to Kenya soon after Ludwig’s death. In this she assures Arnold that, “even in spite of Hitler, who spoiled our last years”, her marriage to Ludwig had left a residue of happiness that grief could never eradicate.

When Arnold died in 1992, Fr Walshe was asked to perform the burial service. Since then, having laid one of the family to rest in his country of exile, he began to wonder about the location of the graves of Ludwig and Liselore in theirs. At first, he assumed it must be in one of Dublin’s Jewish cemeteries.

But earlier this year, a sister of the priest found the plot in Mount Jerome. Predictably, it was somewhat neglected. And although it remains ravaged by the passing of seven decades, the Walshes have since tidied it up: an act of respect to a family separated by war and, indirectly, a small contribution to Dublin City of Science 2012.