Furth emigrated to the United States in 1941. He graduated from Harvard University with a Bachelor's degree in 1951 and received his Ph.D. from Harvard in 1960. Furth worked at Lawrence Livermore National Laboratory for several years before going to Princeton Plasma Physics Laboratory where he would spend the rest of his career working in plasma physics and nuclear fusion. He was also a professor of astrophysics at Princeton University.
In the late 1960's Furth contributed some important theoretical work on resistive magnetohydrodynamics instabilities in a slightly resistive plasma.
In 1981 Furth became the director at PPPL and led the laboratory until 1990 during record setting magnetic fusion energy experiments on the largest tokamak in the country, the Tokamak Fusion Test Reactor (TFTR).
Furth was a member of the National Academy of Sciences and died of a heart ailment.