The Development of Key Instruments for Science

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The Development of Key Instruments for Science


The unaided human eye can see individual objects as small as a few tens of microns, can detect single photons (when dark-adapted), and can see objects millions of light-years away in space. Our fingertips can feel differences in texture resulting from features less than a thousandth of an inch high, and our other senses can detect similarly small differences in molecular concentrations (taste and smell) and vibration (hearing). Yet, our eyes are poor compared to a hawk's, we cannot hear or smell as well as most dogs, and we cannot begin to duplicate a salmon's ability to taste the waters of its home stream. In order to explore and understand our world and universe, we must extend our senses further still. So we have learned to make telescopes that can see nearly to the beginning of time and microscopes that can see individual atoms. And whatever we can see, we have learned to measure. Our ability to understand our world is limited by our senses, as they have been augmented by our scientific instruments, descendents of the first telescope, the first microscope, and other devices for observing and measuring the world and the universe in which we live. The growth, then, of ever-more sophisticated scientific instruments has had a significant impact on our view of the world, the universe, and ourselves.


There is no doubt that for as long as humanity has existed, we have squinted at objects impossibly tiny or off in the distance. We have done so to try to understand the world in which we find ourselves, or simply out of wonder and curiosity. And where our senses were unable to take us, our imagination picked up, resulting in fanciful hypotheses in areas too numerous to mention. Our early astronomical observatories date to the time of Stonehenge or before, and the Babylonians, Egyptians, Mayans, Chinese, and most other cultures have some history of naked-eye astronomical observations.

At the same time, the small has fascinated us, too. Unable to see individual cells, we wondered what the human body was made of, the biology of fertilization, and where disease came from. We felt that we should be able to measure anything we could detect, no matter how large or small, while the use of ever-more-complex calculations made early scientists yearn for a way to reduce the drudgery of endless arithmetic.

In the sixteenth century humanity began to overcome some of these limitations. The Renaissance saw the invention of the telescope, the microscope, precision measuring devices, and rudimentary calculating devices. All of these helped scientists to see things previously only speculated about, and in many cases, what was seen was completely unexpected. As a result, humanity's notions of how the world worked were turned upside down.


The impact of these new instruments on science and on society was profound and nearly universal. Although a great many instruments were developed during this time, we will concentrate on the scientific and societal impacts of only four: the telescope, the microscope, the vernier caliper, and calculating devices.

The Telescope

Although there is some evidence of lenses going back over 2,000 years, the first telescope was not consciously made until sometime in the late sixteenth or early seventeenth centuries. The standard story is that a Dutch spectacle maker by the name of Hans Lippershay (c. 1570-1619) invented the first telescope, but it was almost certainly invented earlier, and Lippershay was simply the first to apply for a patent (later denied) in 1608. By 1609 Galileo (1564-1642) had heard about the device and made one of his own that turned out to be a significant improvement over Lippershay's. Over the next century the telescope was improved by a number of people, including Galileo and Isaac Newton (1642-1727), coming to roughly modern form (in design, if not in size) relatively quickly.

The telescope was a boon to scientists and the bane of the Church and tradition. Looking through a relatively simple and inexpensive device, astronomers found that the Moon's face was cratered and mountainous, the Sun's face was mottled with dark spots, the Milky Way was actually a collection of uncountable stars, Jupiter had both bands and moons, and much more. Galileo was actually threatened with excommunication from the Catholic Church unless he renounced his unsettling discoveries. However, within a century, scientists had accepted the fact that Earth was not the center of the universe, that the Sun and the Moon were not perfect and unblemished spheres, and that other planets had their own satellite systems.

These discoveries had the result of displacing Earth from a special place in the cosmos. Once Earth's motion around the Sun was confirmed, we could no longer claim to live at the center of the universe. We were simply one planet of many around a star that later observations were to show was really nothing special, either. Until Galileo's observations, and those that were to follow, man could claim to be the favored species of God, living at the center of Creation. Ultimately, developments in new and different telescopes have given us "eyes" above the atmosphere and in wavelengths not even known to exist by Newton. We can now see back in time almost to the big bang (at least, to within about a million years of the big bang) and can look at our universe in wavelengths ranging from gamma rays to radio waves. And with each new improvement, we continue to find explanations, new phenomena, and still more questions.

The Microscope

If the telescope gave us the ability to peer outwards into the universe, the microscope has given us the ability to gaze within; within ourselves and within just about any other object we care to examine. The microscope may have been invented by Lippershay, too, although Sacharias Jansen (1588-c. 1628) is thought to have performed important work as well, and Robert Hooke (1635-1703) was among the first to make microscopic discoveries widely known.

Just as the telescope gave us an entirely new way to look at the heavens, the microscope gave us an unprecedented ability to look at ourselves and the details of our world. Cells were discovered in cork, showing us for the first time what our bodies were made of. Pond water was shown to be swarming with microscopic life, leading eventually to the germ theory of disease upon which so much of public health is based. More discoveries followed, and each of them showed more detail about how the living world worked.

These discoveries, in turn, helped to show again that humans did not differ significantly from other animals. Like them, we were comprised of cells, and most of these cells looked like their counterparts in the animal world. This was another indication that, although gifted with the power of abstract thought, mankind was also a member of the animal kingdom, and was likely not placed on a pedestal. At the same time, biological and medical research performed with these microscopes has led to an immeasurable increase in human medical knowledge, and it's safe to say that much of the success of modern medicine is based in whole or in part on the microscopic examination of tissues, germs, and more.

Over the intervening centuries, the microscope, too, has been expanded in capability and in utility, now finding uses in geology, materials science, and more. Modern microscopes include the confocal microscope, able to focus on very small slices of individual cells; the electron microscope, which can image viruses and smaller objects; and the atomic force microscope, which can "see" and manipulate individual atoms.

The Vernier Caliper

Although often overlooked or taken for granted, the ability to make precise and accurate measurements is crucial to both science and technology. Manufacturing a steam engine, for example, requires one to measure with sufficient accuracy that a piston will slide freely in a cylinder, neither binding to the sides nor leaving such a gap that steam leaks out. Similarly, making a telescope requires grinding lenses and fitting them to a tube with some degree of precision. These tasks are both dependent on the ability to make dimensional measurements that are precise and accurate.

One of the first precision measuring devices was invented in the early seventeenth century by French mathematician Pierre Vernier (1584-1638). This device, still called a "vernier," consists of two scales, a main scale and a sliding scale. Using this, one can measure dimensions with a fairly high degree of precision and accuracy. In fact, vernier calipers are still in common use in machine shops, scientific laboratories, instrument shops, and elsewhere because of their simplicity and accuracy.

The vernier was, of course, only the first precision measuring instrument. In the intervening centuries, measuring technology has expanded greatly to the point where scientists can directly weigh individual molecules, can measure lengths to a matter of angstroms, or can measure distances to the edge of the visible universe. In many ways, science and technology can only advance to the limits of what we can measure, because what we cannot measure, we cannot scientifically understand. And with these increased powers of measurement, our ability to understand our place in the universe and our ability to manipulate our world have increased substantially, contributing directly to the development of engines, aircraft, and modern electronics, among others.

Calculating Devices

The last of the devices this essay will address is the calculating device. Until John Napier (1550-1617) developed the first slide rule in 1617, all calculation was performed by hand. As anyone who has labored through a difficult series of calculations can attest, working through involved calculations by hand greatly increases the opportunity to make mistakes, often requiring each set of calculations to be repeated several times to ensure everything was done properly. To get an idea of the work involved, try to picture one of the lengthy tables of logarithms or trigonometric functions often still found in the back of mathematics textbooks. Now, try to picture calculating all of those numbers individually, by hand, without the benefit of a calculator or computer. Yet this is precisely how such tables were originally constructed.

The first slide rule simplified these calculations enormously by making the basics of multiplication and division mechanical rather than mental. Assuming the slide rule was made properly, all one had to do was to line up the appropriate numbers and read out the answer according to some simple rules. Not only was much of the labor taken out of these calculations, but the chances of error were reduced substantially. Scientists, engineers, and mathematicians became more accurate as well as more productive.

As with the other devices mentioned here, the process of calculation has advanced beyond Napier's dreams in the intervening centuries. Surprisingly, the slide rule survived almost unchanged for nearly 350 years before being supplanted by the hand calculator in the 1970s. Since that time, electronic calculators have become more powerful than the earlier computers, while computers and computer-aided computation have gained the ability to perform more calculations in a few minutes than an early mathematician could have performed in a lifetime.

The impact of calculating devices on society and the ability to perform calculations rapidly and accurately has been a tremendous boon to science and technology, as well as to the worlds of finance, insurance, business, and more.


The last centuries of the Renaissance saw the development of the first of what became a centuries-long succession of scientific instruments and devices. These devices helped to reduce much of the tedium of scientific calculation, made possible the development of precision machinery, and extended the range of human senses immeasurably. With all of this, our ability to understand and manipulate our world, our universe, and ourselves also increased greatly. This, in turn, helped humanity to gain a better understanding of our place in the universe.


Further Reading

Brecht, Bertholt. Galileo. New York: Grove Press, 1966.

King, Henry C. The History of the Telescope. Cambridge, MA: Sky Publishing, 1955.

Maor, Eli. E: The Story of a Number. Princeton, NJ: Princeton University Press, 1994.

Morrison, Philip, and Phylis Morrison. Powers of Ten: A Book about the Relative Size of Things in the Universe and the Effect of Adding Another Zero. Redding, CT: Scientific American Books, 1982.

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The Development of Key Instruments for Science

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The Development of Key Instruments for Science