Knocking on Heaven's Door - Lisa Randall [19]
My trip was auspiciously timed, as 2009 was the 400th anniversary of Galileo’s first celestial observations. The citizens of Padua were particularly attentive, since Galileo had been lecturing at the university there at the time of his most significant research. To commemorate his famous observations, the town of Padua (as well as Pisa, Florence, and Venice—other towns that figured prominently in the scientific life of Galileo) had arranged exhibits and ceremonies in his honor. The physics talks took place in a hall in the Centro Culturale Altinate (or San Gaetano), the same building that housed a fascinating exhibit that celebrated Galileo’s many concrete accomplishments and highlighted his role in changing and defining what science means today.
Most people I met appreciated Galileo’s achievements and conveyed their enthusiasm for modern scientific developments. The interest and knowledge of the Paduan mayor, Flavio Zanonato, impressed even the local physicists. The head of the city not only actively engaged in scientific conversation at a dinner following the public lecture I gave, but during the lecture itself he surprised the audience with an astute question about charge flow at the LHC.
As part of the citizenship ceremony, the mayor gave me the key to the city. The key was fantastic—it lived up to my movie images of what such a thing should be. Large and silver and nicely carved, it prompted one of my colleagues to ask if it was out of a Harry Potter story. It was a ceremonial key—it doesn’t actually open anything. Yet it was a beautiful symbol of entry—to a city of course but also, in my imagination, to a rich and textured portal of knowledge.
In addition to the key, Massimilla Baldo-Ceolin, a professor at the University of Padua, gave me a Venetian commemorative medal known as an osella. It is engraved with a quote from Galileo that is also on display at the physics department of the university: “Io stimo più li trovar un vero, benché di cosa leggiera, che ‘l disputar lungamente delle massime questioni senza conseguir verità nissuna.” This translates as “I deem it of more value to find out a truth about however light a matter than to engage in long disputes about the greatest questions without achieving any truth.”
I shared these words with many colleagues at our conference since this is in fact a guiding principle to this day. Creative advances often originate with tractable problems—a point we will return to later on. Not all the questions we answer have immediately radical implications. Yet advances, even seemingly incremental ones, occasionally lead to major shifts in our understanding.
This chapter describes how the current observations that this book presents are rooted in developments that occurred in the seventeenth century, and how the fundamental advances made at that time helped define the nature of theory and experiment that we employ today. The big questions are in some respects the same ones that scientists have been asking for 400 years, but because of technological and theoretical advances, the little questions we now ask have evolved tremendously.
GALILEO’S CONTRIBUTIONS TO SCIENCE
Scientists knock on heaven’s door in an attempt to cross the threshold separating the known from the unknown. At any moment we start with a set of rules and equations that predict phenomena we can currently measure. But we are always trying to move into regimes that we haven’t yet been able to explore with experiments. With technology and mathematics we systematically approach questions that in the past were the subject of mere speculation or faith. With better and more numerous observations and with improved theoretical frameworks that encompass newer