Emmett Brown Marty departs in the DeLorean for 1985, Doc starts a family with Clara; the couple have two sons, Jules and Verne. He eventually builds another time machine out of a steam locomotive, and the Browns return to 1985 in order to pick up Einstein before setting out for another adventure. Emmett Brown Emmett Lathrop "Doc" Brown, Ph.D., is a fictional character in the "Back to the Future trilogy" in which he is the inventor of the first time machine, built out of a DeLorean sports car. The character is portrayed by Christopher Lloyd in all three films, as well as
PH to a straight line with respect to standard buffer values. Commercial standard buffer solutions usually come with information on the value at 25 °C and a correction factor to be applied for other temperatures. The pH scale is logarithmic and therefore pH is a dimensionless quantity. This was the original definition of Sørensen, which was superseded in favor of pH in 1909. However, it is possible to measure the concentration of hydrogen ions directly, if the electrode is calibrated in terms of hydrogen ion concentrations. One way to do this, which has been used extensively, is to titrate a solution