Rodolfo Gambini is a professor at the University of the Republic in Uruguay. He is a past president of the Uruguayan Academy of Sciences and has held several high level posts in funding agencies in Uruguay. He is the recipient of numerous awards including the Trieste Physics prize and is a member of the National Academy of Sciences of Argentina and of the Latin American Academy of Sciences. He co-authored with Pullin a monograph on loop quantum gravity published by Oxford University Press. Jorge Pullin is the Horace Hearne Chair in Theoretical Physics at the Louisiana State University. He was the founding editor of Physical Review X. He has received numerous awards including Alfred P. Sloan, John S. Guggenheim and Fulbright fellowships. He is a member of the National Academies of Science of Argentina and Mexico and of the Latin American Academy of Sciences. He co-authored with Gambini the only textbook for undergraduates on loop quantum gravity published by Oxford University Press and a volume for the celebration of 30 years of the field with Abhay Ashtekar published by World Scientific, Singapore.