 Show Who Was Robert Hooke? Lister and the Achromatic Microscope The Cleveland Connection Imagine a world where we could not identity disease-causing bacteria or cancerous cells? Pathology, bacteriology, even forensics and genetics, all owe a deep debt to the humble microscope. What began as a bead of glass for magnifying became the complex scopes that allow us to see even the smallest particles of our world! By Ryan D. Tweney Four hundred years after its invention, the telescope has become an essential scientific instrument, an icon of science. But it is more than just an extension of our senses — the telescope is an instrument of thought as well. Throughout its 400-year history, the telescope has changed our view of the universe and our view of ourselves. Never more so than at the very beginning. News of Hans Lippershey's 1608 patent reached Galileo Galilei the following year. Within one day, he had made his own telescope, and, in 1610, published a short, still very readable, book, Siderius Nuncius, (The Starry Messenger). This remarkable work changed everything. Galileo's telescope made clear that the universe was far larger than had been imagined — and our place in it far smaller than had been imagined. The public impact was immediate. The poet John Donne, in 1611, wrote of "Galileo … who of late hath summoned the other world, the stars to come nearer to him, and give him an account of themselves." But this new other world, as Donne also saw, had a negative side. The old universe of unity and proportion, crowned by a perfect heaven scaled to human proportion, was threatened: "New philosophy calls all in doubt." Today you can buy a better telescope than Galileo's for under a hundred dollars, and a careful replica of his telescope for a great deal more. An ordinary pair of binoculars will show just about all that he saw (DON'T try to use them to see the sunspots!). But you can only imagine how unsettling this modest instrument was in the early 17th century. We now take for granted that science gives us otherwise invisible worlds. We have wonderful instruments that do this — the telescope, the microscope, fMRI brain scans, the Large Hadron Collider. We now see many invisible worlds: tiny bacteria in our water, shifting patterns of blood flow in the brain, submicroscopic particles (some hope) that haven't been seen since the first microseconds of the universe. Some doubted what Galileo was brilliant at answering these doubts partly because he was not merely revealing facts; instead, they were facts in the context of new theories about the universe, especially the Copernican theory, that the sun, not the Earth, was the center of the universe. These were hard questions then, just as hard questions today still cluster about science. How do we know that a black hole sits at the center of our galaxy? No light escapes from a black hole — we can only detect them by their effects on nearby matter. Telescopes are important in proving their existence, but the telescopes used are very different from Galileo's, and they carry their own burden of doubt, theory and proof.
The invention of the telescope played an important role in advancing our understanding of Earth's place in the cosmos. While there is evidence that the principals of telescopes were known in the late 16th century, the first telescopes were created in the Netherlands in 1608. Spectacle makers Hans Lippershey & Zacharias Janssen and Jacob Metius independently created telescopes. The telescope emerged from a tradition of craftsmanship and technical innovation around spectacles and developments in the science of optics traced back through Roger Bacon and a series of Islamic scientists, in particular Al-Kindi (c. 801–873), Ibn Sahl (c. 940-1000) and Ibn al-Haytham (965–1040). The story of Galileo's telescopic observations illustrates how a tool for seeing and collecting evidence can dramatically change our understanding of the cosmos. Early telescopes were primarily used for making Earth-bound observations, such as surveying and military tactics. Galileo Galilei (1564-1642) was part of a small group of astronomers who turned telescopes towards the heavens. After hearing about the "Danish perspective glass" in 1609, Galileo constructed his own telescope. He subsequently demonstrated the telescope in Venice. His demonstration of the telescope earned him a lifetime lectureship. After his initial success, Galileo focused on refining the instrument. The initial telescope he created (and the Dutch ones it was based on) magnified objects three diameters. That is, it made things look three times larger than they did with the naked eye. Through refining the design of the telescope he developed an instrument that could magnify eight times, and eventually thirty times. This increased magnification of heavenly objects had a significant and immediate impact. These new observations were by no means exclusive to Galileo. The story of Galileo and the telescope is a powerful example of the key role that technologies play in enabling advances in scientific knowledge. With that said, the telescope isn't the only technology at play in this story. Galileo deftly used the printed book and the design of prints in his books to present his research to the learned community. This is not a story of a lone thinker theorizing and piecing together a new model of the cosmos. Quite the contrary, an array of individuals in the early 17th century took the newly created telescopes and pointed them toward the heavens. Unlike those other observers, however, Galileo rapidly published his findings. In some cases, Galileo understood the significance and importance of these observations more readily than his contemporaries. It was this understanding, and foresight to publish, that made Galileo's ideas stand the test of time. Starry Messenger, Galileo's Rapidly Published FindingsShortly after his first telescopic observations of the heavens, Galileo began sketching his observations. He wanted to get his findings out. His observations and interpretations of stars, the moon, Jupiter, the sun and the phases of the planet Venus, were critical in refining our understanding of the cosmos. In March of 1610, Galileo published the initial results of his telescopic observations in Starry Messenger (Sidereus Nuncius), this short astronomical treatise quickly traveled to the corners of learned society. The Moon is not a Perfect SphereThe engravings of the Moon, created from Galileo's artfully drawn sketches, presented readers with a radically different perspective on the Moon. Due to Galileo's training in Renaissance art and an understanding of chiaroscuro (a technique for shading light and dark) he quickly understood that the shadows he was seeing were actually mountains and craters. From his sketches, he made estimates of their heights and depths. These observations, only possible by the magnifying power of the telescope, clearly suggested that the Aristotelian idea of the Moon as a translucent perfect sphere (or as Dante had suggested an "eternal pearl") were wrong. The Moon was no longer a perfect heavenly object; it now clearly had features and a topology similar in many ways to the Earth. The notion that the moon had a topology like the Earth led to speculation on what life might be like on the Moon. It's now understood that English astronomer Thomas Harriot, (1560-1621) made the first recorded observations of the Moon through a telescope, a month before Galileo in July of 1609. Moreover, the map Harriot created of the Moon in 1612 or 1613 is more detailed than Galileo's. Harriot observed the Moon first, and the maps he created included more information, but he did not broadly distribute his work. However, over 500 copies of the Starry Messenger were printed and sold, solidifying Galileo's legacy in astronomy. Jupiter has its Own MoonsWhen Galileo turned his telescope to observe Jupiter, he saw what he initially thought to be three previously unobserved fixed stars. After continued observations it became clear that they were not fixed, and in a matter of days he had come to the conclusion that these new stars were in fact orbiting Jupiter. He had discovered three of the largest moons of Jupiter. The implications of this discovery, of objects orbiting a planet, were part of what pushed Galileo to argue for a sun-centered cosmos. Jupiter's moons countered a key argument against the Earth orbiting the sun. Critics of Copernicus' sun-centered cosmos asked, how could the Earth drag the moon across the heavens? Remember, the idea of the underlying mechanism of gravity wouldn't come until Newton's Principia Mathematica in 1687, which makes this both a reasonable and important question. Since there was wide agreement that Jupiter was already in motion, the fact that Jupiter clearly had its own moons offered a clear refutation of an important critique of the heliocentric system. In Mundus Jovialis (1614), Simon Marius claimed that he, not Galileo, had first discovered the moons of Jupiter. In his times, Marius was publicly condemned as a plagiarist. Galileo had published his results already in 1610 and was rather well known and powerful in renaissance court. Only in the 19th century, would historians return to examine the evidence. It turns out that Marius had not plagiarized Galileo. Clearly his observations were different; in fact he had more accurately charted the orbits of Jupiter's moons. It's now broadly understood that Marius was an independent observer of Jupiter's moons. A Spotted Rotating SunIn observing the sun, Galileo saw a series of "imperfections". He had discovered sunspots. Monitoring these spots on the sun demonstrated that the sun in fact rotated. Furthermore, later observations by Francesco Sizzi in 1612 suggested that the spots on the sun actually changed over time. It would seem that the Sun, like the Moon, was not the perfect sphere that learned Europeans thought of as a key feature of their universe. These sunspots were also independently observed by the Jesuit priest and astronomer Christoph Scheiner (1575-1650). Scheiner observed sunspots in 1611 and published his results in 1612. Over the course of their careers Galileo and Schiener feuded over who should get credit for the discovery. Unbeknownst to either of them, Thomas Harriot had observed them in 1610 and the German theologian, David Fabricius and his son Johanes likely beat both Scheiner and Galileo to the publication of the discovery with their Apparente earum cum Sole Conversione Narratio in June of 1611. However, their publication was not widely circulated and thus remained obscure in its times. Outside the western tradition of science. Chinese astronomers have long observed sunspots, going back to at least 165 BC.
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Why might inventions such as the telescope and microscope change the way people saw the world?
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