In 1933 Albert Einstein's house in Germany was raided by agents of the newly appointed Nazi government. The Nazis had systematically denounced both Einstein and his work, calling his relativity theory “Jewish science”.
Fortunately, Einstein was on tour in the US when Hitler rose to power. Instead of being murdered, he became the world's most famous refugee.
Fame can open doors, and after a period in England under permanent guard he was offered a position at Princeton, but even the greatest scientist of the age had a lobby group arguing he should not be allowed to settle in America. Thousands of lower profile Jewish scientists also fled Germany, but usually received less friendly receptions. Many leading American academic institutions had a “Jewish quota”, and thousands of refugees were turned back to eventually die in concentration camps.
Yet those who escaped represented an astonishing abundance of genius, many of whom played a crucial part in the Allies winning the Second World War and in building the scientific institutions and companies of the countries in which they settled. The combination of European theory and American application has been credited with much of the scientific progress made in the 1940s and '50s.
The '30s and '40s represent the peak of scientific flight, but the multiple Nobel Prize winners, past and future, who settled wherever they could were far from unique. Scientists are often seen as troublemakers by repressive regimes. Fortunately, many of history's greatest scientists have found countries that wanted to take them. However, we don't know how many younger geniuses had their potential snuffed out because no government would accept them.
These are a few of the scientific giants on whose shoulders we stand, and whose lives once depended on finding refuge in a country more accepting than their homeland.