Letters from Albert Einstein giving colleagues his thoughts on physics, God and Israel in the 1950s go under the hammer at a Jerusalem auction house on 20 June. The website of Winners auction house describes five signed letters written in English between 1951 and 1954. The site gives current estimates of their combined value as between $31,000 and $46,000 (R395,690 and R587,153). In a 1951 letter to eminent physicist David Bohm, Einstein discusses Bohm's linkage between quantum theory and "relativistic field theory". "I must confess that I am not able to guess how such unification could be achieved," Einstein writes.