When Einstein first used his equations to predict the transverse gravitational red shift of photons and the gravitational slowing of clocks, the effect was so small that it seemed impossible to measure. It was not until four years after his death that the effect was finally accurately measured in the laboratory. In 1959, Robert Pound and Glen Rebka made very accurate measurements of both red and blue transverse Doppler effects in the momentum of gamma ray photons produced by vertical differences in gravitational escape/surface velocity esV between the top and bottom of Harvard’s Jefferson Tower. The measured values of this experiment do not support Einstein’s downward pointing theory of gravity.