The Legend of The Hale Telescope
Over the last decade, Corning® Gorilla® Glass has innovated the way we look at and understand our mobile devices. But did you know that Corning also has nearly a hundred-year-old legacy of innovating the way we look at and understand the outer reaches of space?
October 4-10th is World Space Week and this year’s theme is “Space and Entrepreneurship.” Today, those two words probably conjure up thoughts of commercial space flight or space tourism. But instead of looking into the future, let’s look at an amazing feat of space entrepreneurism from the past.
In the late 1920s, astrophysicists were trying to understand more about the evolution of stars and the universe itself. To do this they needed a better way to observe the night sky. In 1928, the John Rockefeller Foundation sponsored a $6M grant to help advance science and sought out prominent scientist and astronomer, George Ellery Hale. The foundation commissioned Hale to build a 200-inch telescope which, at the time, would have been the largest telescope in history.
In 1934, Hale turned to material science experts at Corning Glass Works (later to become Corning Incorporated ) to help create the mold for the telescope’s mirror blank. A mirror blank is the material that a reflective coating for a mirror design is applied, and in this case, the material used was glass. Dr. George McCauley, a Corning physicist, designed and directed the project. No stranger to a challenge, Corning set out to create the largest piece of glass ever built using their heat resistant material, PYREX®, to make Hale’s giant telescope a reality.
It would take nearly a month to melt the 65 tons of PYREX® mixture. The waffle-like mold designed to reduce the weight of the glass was the first of its kind, and no one knew what would happen to the 26-inch thick glass when it cooled. If it cracked it would mean the entire telescope was useless.
The newspapers of the day were constantly reporting on the progress of the giant “200-inch” telescope which they dubbed, “The Giant Eye,” for obvious reasons.
On the day Corning was to pour the glass into the mold, there was so much publicity that the small town of Corning, NY suddenly had dignitaries from all over the world descending upon it to observe the spectacle. Ten thousand people applied for permits to watch the glass pouring live. It took a team of Corning gaffers over ten hours to fill the mold with more than a hundred ladles of glass, each weighing over 750 pounds.
As the glass began to cool, the onlookers were dismayed to see the mold had broken from the tremendous heat. But as most entrepreneurs, scientists, and engineers know, failure doesn’t mean the end, it’s a lesson on how not to do something the next time you try it. There’s a famous quote by Thomas Edison (who by the way also worked with Corning on the light bulb), “I have not failed 10,000 times, I’ve successfully found 10,000 ways that will not work.” Fortunately for Corning, it only took one time to figure out what didn’t work.
When Corning poured the glass for a second time, they did it without a live audience, and the pouring was a success. The mold was placed in an annealing oven to gradually cool a few degrees per day, and it would take a year for the glass to completely cool.
Corning measured the glass temperature every day for six months until another challenge arose – a flood in the summer of 1935.
Corning is located near the Chemung River, which at the time, was prone to flooding. Fortunately, Dr. McCauley had built the equipment for this project high above any known flood mark. Due to this careful planning, when the factory floor flooded it didn’t reach the equipment or the cooling glass.
The fire department was quickly brought in to help pump water out of the factory, but to do so meant they would have to turn off the power – for three days. This meant that the Giant Eye was cooling (annealing) at an uncontrolled rate, and no one knew what the implications of that might have on the glass. After five more months, Dr. McCauley finally decided it was time to take the glass out of the annealing oven, and in October of 1935, they saw that the Giant Eye was in fact in one piece.
For most people who lived during this generation, they recalled where they were when the Giant Eye traveled by rail across the country from New York to California. Thousands of people lined the railroads to catch a glimpse of science’s glass darling and felt a surge of hope about the discoveries it might bring. The excitement and anticipation echoed modern-day feelings of watching rockets launch into outer space.
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Ultimately, the Giant Eye would end up on top of the Palomar Mountain outside of San Diego. Today, it is known as the Hale Telescope in the Palomar Observatory and owned and operated by Caltech. The Hale Telescope has made significant discoveries over its almost 100-year history. Most notably, it helped astronomers better understand the expansion of the universe, stellar population (which helps scientist understand what stars are made of,) and founded discoveries of quasars beyond the Milky Way (several billion light-years away)!
The first disc that Corning poured is now housed on display in the Corning Museum of Glass in their Innovations Center. The Hale Telescope has taught countless people about mirrors that are used in reflecting telescopes (the telescopes used for space exploration) and perhaps has inspired countless more to pursue a career dedicated to continuing the advancement of space exploration.
When you look through and touch the glass on your phone today take a second to think about the innovation and significance of that material - glass. It’s a wonderous material that has a long and important history and is and has been vital to understanding space and the universe.
To learn more about Corning’s history with space and our advanced optics solutions for the aerospace industry visit:
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