Three Roads To Quantum Gravity

KNOTS, LINKS AND KINKS
133
Trias had already been using for several years in their work on
QCD. Even though they had been publishing in the Physical
Review, which is a major journal, we had somehow missed
seeing their work.
With a heavy heart we did the only thing we could, which
was to sit down and write them a very apologetic letter. We
heard nothing from them until one afternoon in Trento, when
Carlo got a phone call from Barcelona. Our letter had ®nally
reached them. They had tracked us down to Trento, and
asked if we would still be there tomorrow. The next morning
they arrived, having driven most of the night across France
and northern Italy. We spent a wonderful day showing each
other our work, which was thankfully complementary. They
had applied the method to QCD, while we had applied it to
quantum gravity. Anthony Trias did most of the talking,
while Rodolfo Gambini sat at the back of the room and at ®rst
hardly said anything. But we soon found that Rodolfo was a
creative scientist of the ®rst order. Just how creative we
learned over the next few months, as he quickly invented
a new approach to doing calculations in loop quantum
gravity.
Since then Gambini has been one of the leaders in the ®eld
of quantum gravity, often working in collaboration with Jorge
Pullin at Penn State University and a very good group of
young people he trained in Montevideo. They have discovered
many more solutions to the equations of quantum
gravity, and resolved several important problems that came
up along the way.
It also must be said that, despite his quiet nature, Rodolfo
Gambini has been more or less single-handedly responsible
for reviving physics in both Venezuela and Uruguay after its
total destruction by the military dictatorships. Just what this
meant was brought home to me the ®rst time I visited
Montevideo. It was the middle of winter, and we did physics
with Rodolfo and his group in a run-down old convent,
without heat or computers, ®ghting off the cold by drinking
a continuous supply of matte (a kind of tea) that was kept hot
over a Bunsen burner. Now the science departments at the
University of Uruguay are housed in modern buildings and