Scientific American has a personal recollection piece about David Bohm that captures just a slice of his humanity and his genius.
Bohm did a PhD thesis at UC Berkeley under J Robert Oppenheimer which offered basic insights into the physics of plasmas. This was toward the beginning of the reign of Joe McCarthy and the Unamerican Activities Committee, which introduced the phrase witch hunt into the American lexicon. [Oliver Stone’s video] Bohm was commanded to testify against another student, who was a Berkeley activist, and he refused. In retribution, the HUAC blacklisted him and, though he was one of the most brilliant physicists of his generation, no university could hire him. His thesis was classified, so that he could not publish it nor talk about it in applying for jobs. He fled to University of São Paolo in Brazil, and the State Department took away his passport, so he could not attend scientific meetings or interview for professorships outside Brazil.
It was during this time that Bohm did some of his most important and original work, writing a textbook about quantum mechanics that offered a new view of what it means. Eventually, Bohm found asylum in England, and a professorship at University of London. He could not return to the US because there was a warrant for his arrest.
Later in his life, Bohm offered us a fundamental insight into physics that we know how to study and physics that is impossible to study by our usual methods. What we know how to study are patterns in space and time, where things close together are related to one another, and where an event has effects that ripple out from that center, becoming weaker as the waves travel further out. What is so difficult to study are patterns that are spread over space and time, but the laws of quantum mechanics suggest that fully half the order in the universe is spread out in this way.
What appears to us as disorder or randomness or Heisenberg’s uncertainty is actually not disorder at all, but rather an order that is spread out so that we cannot see it with our eyes or instruments. For example, if you put a drop of ink into a glass of water and stir the water, the dot disappears as the ink spreads through the water. On a microscopic level, all the information is still there, specifying where the water was clear and where the ink drop was. Under some conditions, you can actually unstir the water, and get your ink drop back. (The secret ingredient in this video is corn syrup.)
Bohm gave us the insight that half of physics is hidden from us in a form that he dubbed the Implicate Order. Bohm became a disciple of Krishnamurti, and though he never wrote about the connections of quantum mechanics to spirituality, his work was popularized by Nick Herbert, Gary Zukav, Fritjof Capra, and others.