Friday, August 16, 2019

The Glass Age - How Glass Invented Our Modern World



Glass is a beautiful and useful substance. It occurs naturally in the form of obsidian, tektites and other forms. It has been used by humans for thousands of years as tools and ornaments. It was well known in the ancient world and was highly prized because of its beauty and rarity. The Bible contains several references to glass such as, “Gold and glass cannot equal wisdom,” Job 28:17. While it has been known and used for millennia, it was generally only the wealthy that could afford it. Its usefulness was mostly aesthetic. During the Stone, Bronze, and Iron ages glass was a novelty.

So many new forms of technology have been developed in the last century alone we have multiple “age” names to describe it including atomic age, space age, computer age, information age, etc. While these names are descriptive of very important technologies and advancements, one substance has arguably made them all possible. Its use covers a much larger span of recent history and almost single-handedly made the scientific revolution possible over the past 500 years. What is this magical substance? Glass of course.

Glass held an important place in Medieval Europe. Stained glass was central to European Catholic life from the 13-16 century as a key part of the cathedral, the center of society. It was a means of educating the illiterate masses through stained glass mosaics. Mirrors also played a key role in European aristocratic life enabling people, especially women, to spend hours a day perfecting their appearance. Mirrors also seem to have played a significant role in spiritual matters.1 In fact, after Johannes Gutenberg lost his revolutionary printing press to debt collectors, he turned to making mirrors sold to pilgrims for use in spiritual rituals. Because of its place in European society, it is understandable that the Glass Age begins there.

The Glass Age could be considered to start with the invention of man-made colorless glass around 1430.2 Although glassmaking had been around for much longer, the ability to reliably make colorless glass that's highly transparent is what has led to so many technical and scientific breakthroughs. Around the same time as the perfection of colorless glass, the art of blown glass grew in earnest in Venice, Italy. Blown glass had been around since about 1 AD, but in Venice, several significant breakthroughs took place in a short time.

In 1271 the glassmaker’s guild was formed. In 1291, officials passed a law that required all glassmakers and glass artisans to move to the island of Murano. It also forbade them to leave or any foreign glassmakers to make or sell glass in Venice. This concentration of highly skilled craftsman led to Murano becoming the world leader in glass making and likely contributed to the major advancements in glass technology. Around 1430 a skilled glassmaker named Angelo Barovier invented a process for making extremely transparent glass.3 It was known as cristillo, and this see-through glass led to the development of many technologies.4

Perhaps the most important glass tool of the Glass Age is the lens. The invention of transparent glass enabled better lenses to be manufactured for many applications. Eyeglasses were invented and became common in the 13-14th centuries, but these used lenses made of quartz. Glass proved to be a superior material for making precise glasses that suited the wearers needs.5 Alongside the invention of the printing press, eyeglasses were helpful in the spread of ideas through reading because about 75% of adults requires vision correction. Reading was a major cornerstone of the renaissance and the scientific revolution. More importantly, the lens changed science and technology directly. It didn't take long before it made its way into many scientific tools to improve them. Some include the telescope for astronomy and navigation, the microscope for biology, and the magnetic compass for navigation and cartography.

In 1632 Galileo published his finding confirming the sun was the center of the solar system thanks to the telescope he perfected. In 1665 Robert Hooke first described and named the cell of living organisms after many years of observations with a microscope. The lens eventually led to the invention of the camera which enabled documentation in perfect form. It led to a revolution in science, art, entertainment, education, history, and communication and is a central technology of the Information Age (20th - 21st century).

In 1514 Johannes Werner suggested the cross-staff, an instrument for measuring the position of celestial bodies, be used for sea navigation. It was widely adopted shortly after and played a key role in the Age of Discovery (15th – 17th century). The user was required to look directly at the sun in order to calculate its angle to help determine the ships position. Repeatedly looking directly at the sun was painful and so navigators began fixing smoked glass lenses on their cross-staff to reduce the brightness of the sun.6

Colorless glass improved navigation in other ways. The basic navigation compass had been used in primitive forms for millennia. Colorless glass enabled more sensitive and accurate forms to be protected inside wood boxes and brass bezels. One example is the dry compass which could be used in swaying, rocking ships. Glass also allowed the needle to be magnified. The compass was also adapted for surveying and cartography. The compass was a key part of the theodolite invented in 1571 by Joshua Habermel which is still a part of land surveying today.7 Later an optical scope was added to improve visual range.

The surveyor’s compass, also known as the circumferentor, was another adaptation of the basic navigation compass that was central to surveying and cartography for centuries. It was eventually replaced by the more portable prismatic compass in the 19th century. The accuracy of the navigation compass was greatly improved with the invention of the liquid compass in 1690 which is nearly universal today.8

Glass prisms and lenses were incorporated into other navigation tools increasing their accuracy and ease of use. The sextant was invited in 1731 replacing the marine astrolabe and cross-staff. This major innovation allowed navigators to sight the nighttime celestial bodies and acquire their location even when the sun was not shining—a major advantage. These advancements, in turn, improved navigation accuracy reducing travel time thereby increasing trade and the spread of ideas.9

Another key area glass changed was timekeeping. The hourglass made timekeeping easier and more precise. The exact origins of the hourglass aren't clear, but it's generally accepted that it was widely adopted in Europe by the end of the High Middle Ages (around 1500 A.D.). The hourglass was a popular choice for sailors who used it to mark the passage of time, which allowed them to determine their longitude (location east to west). The hourglass was preferred over earlier water clocks because their sand was unaffected by the rocking motion of a ship. They were used onshore to measure time for church services, cooking and work tasks. Eventually, mechanical clocks supplanted the hourglass, though it wasn't until the 18th century that a suitable marine replacement was found. These clocks required a clear glass face to protect their delicate insides.

The window is another great example of how colorless glass improved the modern age. Of course, glass windows have been around since the time of the Romans. The true importance of clear glass windows was not realized until the industrial revolution in the mid-19th century. The see-through window enabled high-speed mechanized transportation in boats, trains, cars, and planes in this era.

Perhaps the most influential role of glass in the past 500 years is in the area of chemistry. Chemistry’s impact in all areas of life hardly needs mention. Most all the advancements of chemistry would likely have been impossible without glass in the lab. It is not just the transparency of glass that was important to chemistry. More critical is the inert property of glass which enables it to be in contact with nearly any chemical and not react. This allowed chemicals to be isolated and studied. Robert Boyle (1627-91) is known widely as the father of chemistry. Boyle used a large glass sphere to create a vacuum chamber. He observed that when he placed a burning candle inside and removed the air, the candle went out. This undermined the antient idea that the four elements, air, water, fire, and earth combined in various ways to make up every substance. Boyle proposed a different definition for an element which we still use today and thus invented modern chemistry—all thanks to that glass vacuum chamber.10, 11

The thermometer was invented by Robert Fludd in 1638. It consisted of a long glass tube with a bulb at one end filled with a liquid such as water, alcohol or mercury. This instrument was important to discoveries in the fields of chemistry, medicine, meteorology, and many other disciplines. Although most modern thermometers no longer use glass, their glass ancestors contributed much to our understanding of the natural world.

Better light sources improved night-time activities and extended the usable hours in a day. Metal and glass lanterns became common in the 18th century.12 Advances in fuel types helped improve their brightness and reliability in the 19th century. Coal gas lanterns helped to make cities night-time friendly. Glass panes protected the flame from wind. The Fresnel lens was patented in 1822 and made lighthouses much brighter which meant ships could navigate coastal waters more safely.13 The handheld lantern with its glass globe or lenses was critical to the railroad which began running at night in 1848. Fresnel lenses were common in railroad signal lanterns. The handheld lantern also lit many homes until the electric light fully replaced it in the mid-20th century. Handheld lanterns are still an important tool for camping today. The electric light bulb was invented by Thomas Edison in 1879. In fact, Edison blew his own glass bulbs for his experimentation.

Glass bottles and jars revolutionized food, beverage, and medicine storage and transportation in the 19th century. Canning was invented by a French chef in 1806. However, their seals frequently failed. The canning jar was perfected by John Landis Mason in 1858. Several companies were producing canning jars by the late 1800s which significantly improved food storage commercially and at home. Bottle making technology experienced many improvements also. Glass bottles were in such high demand by the end of the century that the first fully automatic glass forming machine was invented to make bottles. Work began on this revolutionary machine in 1898 by Michael Owens. It was completed in 1903 and could make more bottles in one hour than an expert glassworker could make in a day. Before long many types of glass products were made by machine instead of people.14

Many of the important developments in glass technology in the past 170 years have been made by the Corning Glassware company. One of their important developments was borosilicate glass which was patented as Nonex. It was one of the first heat-resistant glasses available and was adopted nationally for railroad signal lights in 1908 improving railroad safety. Further research led to the development of Pyrex in 1915 which was widely used in cookware and many other applications. Corning is responsible for inventing many modern glass technologies which are central to the Information Age including fiber optic cables which transmit computer signals at the speed of light, and Gorilla glass which is on the surface of most smartphones, tablets, handheld GPS devices, and other electronic gadgets.15

Glass is more important now than ever before. It is the single most important substance in our modern world. It enables rapid transportation in the form of shatter-resistant windshields. It allows near-instantaneous communication and access to near-limitless knowledge thanks to computer and televisions screens. It is on the face of every touch-enabled smartphone like the one that’s probably in your pocket or hand right now. Glass is also a key component of many computer chips. Glass wafers are used in many computing applications in science and research. Glass has had more impact on modern society than just about any other material. And that is why it is fair to say that we live in the Glass Age.


Written by David F. Garner
Photo Credit: sabinevanerp via www.pixabay.com

2 comments:

  1. I am glad to read this post, it's a good one. I am always looking for quality posts and articles and this is what I found here, I hope you will be adding more in the future. Thanks for sharing. Custom Made Glass

    ReplyDelete
  2. Brisani bay in southern Albania will surprise you with the beauty of its nature. You will find the peace that you are looking for. Albanian Coastline

    ReplyDelete