Knocking on Heaven's Door - Lisa Randall [21]
In addition to experiments—the artificial situations he created to test hypotheses—another of Galileo’s game-changing contributions to science was understanding and believing in technology’s potential for advancing our observations of the universe as it presents itself. With experiments, he moved beyond pure intellect and reason, and with new devices, he moved beyond unfiltered observations.
Much of earlier science relied on direct unmediated observations. People touched or saw objects with their own senses, not through an intervening device that in some way altered the images. Tycho Brahe, who among other things discovered a supernova and accurately measured the orbits of the planets, made the last famous astronomical observations before Galileo entered the scene. Tycho did use precise measuring instruments, such as large quadrants, sextants, and armillary spheres. He in fact designed and paid for the construction of instruments of greater precision than anyone had used before, leading to measurements that were sufficiently accurate to allow Kepler to deduce elliptical orbits. Yet Tycho made all his measurements through careful observations with his naked eye, with no intermediary lens or other device.
Notably, Galileo had an artistically trained eye and an astute musical ear—he was, after all, the son of a music theorist and lutenist—but he nonetheless recognized how observations that employed technology as a mediator to his observations could improve on his already formidable faculties. Galileo trusted that the indirect measurements he could make with observational tools at both large and small scales would go far beyond those made purely with his unassisted faculties.
Galileo’s best-known application of technology was the use of telescopes to explore the stars. His use of this instrument changed the way we do science, the way we think about the universe, and the way we see ourselves. Galileo didn’t invent the telescope. It was invented in 1608 by Hans Lippershey in the Netherlands—but the Dutch used telescopes to spy on others, hence the alternative name of spyglass. Yet Galileo was among the first to realize that the device was a potentially potent tool to make observations of the cosmos not possible with the naked eye. He updated the spyglass invented in the Netherlands by developing a telescope capable of magnifying sizes by a factor of 20. Within a year of being presented with a carnival toy, he turned it into a scientific instrument.
Galileo’s act of observing through intermediate devices was a radical departure from previous ways of measuring and represented a major advance essential to all modern science. People were initially suspicious of such indirect observations. Even today, some are skeptical about the reality of the observations made with big proton colliders or the data that computers on satellites or telescopes record. But the digital data cataloged by these devices are every bit as real as—and in many respects more accurate than—anything we can observe directly. After all, our hearing comes from oscillations of air hitting our eardrums and our vision from electromagnetic waves hitting our retinas and being processed by our brains. This means that we too are a sort of technology—and not a highly reliable one at that, as anyone who has experienced an optical illusion can attest. (See Figure 8 for an example.) The beauty of scientific measurements is that we can unambiguously deduce aspects of physical reality, including the nature of elementary particles and their properties, from experiments