Erwin Chargaff was one of the great biochemists of the 20th-century. He is best known for his demonstration in the late 1940s that certain chemical components of DNA molecules always occur in constant ratios, a result that was crucial to the discovery of the DNA double helix by James Watson and Francis Crick. He was among the first to recognize that the chemical composition of DNA is species specific, another step on the way to elucidating the structure of the human genome.
He died in 2002 at age 97.
In his autobiography, Heraclitean Fire, Chargaff says of his life: "In the Sistine Chapel, where Michelangelo depicts the creation of man, God's finger and that of Adam are separated by a short space. That distance I called eternity; and there, I felt, I was sent to travel."
Chargaff spent his childhood in Austria, in what seemed to him the last golden rays of a more civilized era. He was watching the younger sons of Kaiser Wilhelm II play tennis when news came of the assassination of the Austrian Archduke Franz Ferdinand, an event that plunged all of Europe into darkness. He spent the years between the wars in Vienna, where he took his degrees. Torn between science and the study of literature, he drifted into chemistry, as later he drifted into biochemistry. He was forced to leave Europe by the rise of the Nazis. Again darkness descended. His mother was deported from Vienna into the oblivion of the death camps.
Chargaff was aware at every moment of his life of the immensity of the darkness. As a scientist, he helped make the darkness light. Still, near the end of his life, he was struck by how much we know and how little we understand, and fearful that science was coming dangerously close to bridging the gap between God's finger and the finger of man. "A balance that does not tremble cannot weigh," wrote Chargaff; "A man who does not tremble cannot live."
There is little reason to fear, I think, that science will ever bridge the gap between knowing and unknowing. Our knowledge is finite, and -- as Chargaff suggests -- the gap is eternal. Reason enough to tremble.