The day astronomers used a star’s ancient light to flip a switch in Chicago

Arcturus Starlight Illuminates Chicago’s 1933 World’s Fair Opening

Chicago lit up its 1933 World’s Fair with a 40-year-old beam of starlight.

Edwin Frost had a wild idea: use light from Arcturus to turn on the fair since that light left the star during Chicago’s 1893 fair.

Philip Fox from Adler Planetarium helped plan it all. They set up a system with four observatories to catch the star’s light, turn it into electricity, and send it to Chicago.

On May 27, Fox called each site one by one. When they flipped the switch, a huge searchlight shot into the sky as 30,000 people cheered.

The star wasn’t quite 40 light-years away as they thought, but the magic of connecting two fairs across time still worked.

The Adler Planetarium still tells this cosmic story today.

A Retired Astronomer Hatched a Stellar Plan for Chicago’s 1933 Fair

Edwin Frost came up with a cosmic idea in the early 1930s.

The retired Yerkes Observatory director wanted to use light from the star Arcturus to turn on the lights at Chicago’s Century of Progress World’s Fair.

His plan connected two Chicago events across time – the 1893 World’s Columbian Exposition and the 1933 fair.

Astronomers thought Arcturus was exactly 40 light-years away, creating perfect timing. The starlight reaching Earth in 1933 would have left Arcturus during the 1893 Chicago fair.

Top Scientists Teamed Up to Make Starlight Flip a Switch

Philip Fox helped bring the Arcturus ceremony to life. The planners tackled tough problems like capturing enough starlight to trigger electrical equipment.

As Chicago’s Adler Planetarium director, he joined the planning committee and handled the science side. The team brought together experts from four major American observatories to make the event work.

They got help from big companies too – General Electric provided special tubes, while Western Union handled the signal transmission.

Turning Faint Starlight into Electrical Power Wasn’t Easy

The Arcturus ceremony pushed the limits of 1933 science. Special light-catching cells grabbed the star’s dim light and turned it into tiny electrical currents.

These weak signals went through General Electric tubes that boosted the power. When the signals arrived, they flipped the switch that turned on the fair’s lights.

Western Union telegraph lines carried the stronger signals from the observatories to Chicago’s fairgrounds.

Four Observatories Stood Ready on the Big Night

The team set up four observatories to make sure nothing would go wrong. Harvard Observatory in Massachusetts provided backup from the East Coast.

Yerkes Observatory in Wisconsin served as the main site, with its huge 40-inch telescope pointed at Arcturus.

Allegheny Observatory in Pittsburgh added another location in case of bad weather. The University of Illinois Observatory in Urbana completed the network.

Smart Planners Didn’t Trust the Weather

The team used multiple observatories because they worried about weather problems. May can bring unpredictable clouds, so they needed backup plans.

Each observatory got the same equipment to capture and send Arcturus’s light. The team created clear steps so everyone knew exactly when to start their systems.

This backup approach meant the ceremony could work even if storms covered parts of the country.

Chicago’s Hall of Science Became the Star of the Show

Workers at the fairgrounds set up the Hall of Science building as the center of the event.

They put a powerful searchlight on top that would shoot a bright beam across Chicago’s sky when turned on.

Electricians installed special systems to get the incoming star signal and link it to the fair’s lights. Fair organizers spread the word through newspapers and radio.

By May 27, 1933, thousands of people knew about the cosmic connection about to happen.

Thousands Watched as Starlight Traveled from Space to Chicago

The big night came on May 27, 1933, with 30,000 people gathering at the fairgrounds. The ceremony started at exactly 9:15 PM, when all four observatories could see Arcturus.

Philip Fox stood at the main control area, with phone lines to each observatory. As the moment got closer, the crowd grew quiet.

Many had read about the ceremony in newspapers but found it hard to believe starlight from 40 years ago would actually turn on the fair’s lights.

The Magic Words “Let’s Go” Set Everything in Motion

Fox called each observatory to check they were ready. “Harvard, are you ready?” “Yes.” “Allegheny ready?” “Ready. ” “Illinois ready?” “Yes. ” “Yerkes?”

The answer came back: “Let’s go.” With those words, the system started.

The observatories caught Arcturus’s light, changed it to electricity, and sent the signal to Chicago. The switch flipped, and a massive light beam shot up from the Hall of Science.

The fair’s lights came on, all triggered by starlight that started its journey to Earth in 1893.

Newspapers Called It the “Star of the Show”

The crowd cheered as lights lit up across the fairgrounds. Newspapers across America ran stories about the star event the next day.

The Chicago Tribune called it “the most novel lighting ceremony in history.”

The event caught people’s attention during the Great Depression, offering a moment of wonder and connection to the past.

People talked about how light from a star 40 light-years away had traveled through space just to turn on lights at a fair in Chicago.

Astronomers Later Found a Small Mistake in Their Math

Modern measurements showed that Arcturus isn’t exactly 40 light-years away as 1930s astronomers thought. It’s actually about 37 light-years from Earth.

This meant the light that reached Chicago in 1933 had left Arcturus around 1896, not during the 1893 World’s Fair.

The three-year difference didn’t really matter to the public, though.

The symbolic connection between the two Chicago world’s fairs remained powerful, and few people at the time knew about the small calculation error.

The Star-Light Ceremony Changed How We Mix Science and Spectacle

The Arcturus ceremony broke new ground in connecting astronomy with public events. It showed how scientific principles could create memorable moments that grabbed public attention.

The event proved that photoelectric technology worked in practical applications beyond the laboratory. The ceremony inspired many later events that used astronomical phenomena for public celebrations.

Even today, the 1933 Star-Light Ceremony stands as a landmark moment in science communication, showing how the wonders of the cosmos can connect with everyday life.

Visiting Adler Planetarium, Chicago

The Adler Planetarium at 1300 S. DuSable Lake Shore Dr tells the story of the Arcturus Star-Light Ceremony that opened Chicago’s 1933 World’s Fair using light from a distant star.

Adult tickets start at $19, but Illinois residents get free admission, Wednesday evenings 4-10 PM. The planetarium opens 9 AM-4 PM (closed Tuesdays).

Buy tickets online at adlerplanetarium. org in advance. Special exhibits show Chicago’s astronomical history and the World’s Fair connection.

This article was created with AI assistance and human editing.

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