Surrounded by students delighted with his surprise campus visit on March 15, "Science Guy" Bill Nye ’77 watches for the moment that his eponymous solar noon clock atop Rhodes Hall will indicate the sun's highest position in the sky

Surrounded by students delighted with his surprise visit on March 15, Nye watches for the moment that the clock indicates the sun’s highest position in the sky. (Photo by Ryan Young/Cornell University)

With Cornell’s ‘Solar Noon’ Clock, Bill Nye ’77 Aims to Leave a Legacy

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In March, the ‘Science Guy’ came back to the Hill to check on the Rhodes Hall timepiece, newly overhauled by engineering students

By Joe Wilensky

When Bill Nye ’77—the famed science popularizer, climate advocate, and TV personality—served as a visiting professor on campus in the early 2000s, he’d often walk by Rhodes Hall and notice that in the center of the building’s parapet was an intriguingly blank concrete circle.

“It just didn’t look right—somebody meant to put a clock there,” Nye recalls thinking. “Let’s put a clock there!”

But the instrument that Nye set out to design would be no ordinary timepiece. It would include an indicator of “solar noon”—the highest daily position of the sun in the sky.

Jump ahead some two decades: the Bill Nye Solar Noon Clock is now a campus fixture.

And in March, TV’s beloved “Science Guy” made his latest visit to the Hill, during which he checked out an ongoing overhaul of the clock’s control system by a team of Big Red engineers.

What’s solar noon, anyway?

Only rarely coinciding with 12:00 on a conventional clock, solar noon varies by as much as 20 minutes depending on where you are on the planet. For centuries, seafarers used it for daytime positioning and navigation.

“You would wait, wait, wait for the sun to be the highest in the sky—‘make it noon’ is the expression,” Nye explains. “And then from there, you would calculate everything about your position on the Earth’s surface.”

View of the Bill Nye Solar Noon Clock atop Rhodes Hall. The solar noon indicator, a 14-inch diameter circle below the "12" on the clock's face, illuminates brightly for several minutes each day at solar noon
The 14-inch-wide solar noon indicator disc is located just below the “12” on the clockface, which is 10 feet in diameter. (Photo by Cornell University)

Nye’s interest in the subject stems in part from his father’s experiences in World War II.

Already an amateur astronomer, Ned Nye became fascinated with sundials during his nearly four years in a Japanese POW camp, where he used a sawed-off shovel handle to determine his location and mark the passage of time; he later wrote a book and newspaper columns about sundials.

In designing Cornell’s instrument, Nye’s original idea was to add a slit-shaped skylight to the building to illuminate the clock at solar noon—but calculations showed that to work, the skylight would have had to be nearly 60 feet long. He then thought about the two Solatube lights he has in his L.A. home.

One of the earliest sketches Nye made for the design of his solar noon clock shows how a light-gathering dome atop Rhodes Hall would funnel daylight to the solar noon indicator on the clock's face
An early design sketch. (Image courtesy of Bill Nye)

Each has a roof-mounted, light-gathering dome with a lens that funnels daylight down a highly reflective tube to illuminate a flat disc, as well as internal flaps that can be opened and closed to serve as dimmers.

For the control system, Nye worked with mechanical and aerospace engineering professor Michel Louge, who tapped a group of students to help program and design a system to govern the opening and closing of the mechanism, timed to peak exactly at Ithaca’s solar noon each day.

The clock was unveiled in August 2011 during a daylong celebration that included Nye’s live countdown and play-by-play narration, attended by hundreds.

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Even through Ithaca’s cloudiest days, the instrument did its job—until April 2019, when the software controlling the solar noon indicator failed, a Y2K-like mishap where it suddenly began reading the date as 2099. (The regular timekeeping function, controlled separately, was unaffected.)

A new programming challenge

Like so many projects, fixes to the solar noon indicator (as well as the Engineering college’s planned refreshes to the clock’s webpage design and live cam) were delayed by the pandemic. But in fall 2021, a team of engineering students set to work on repairing it.

Under the guidance of electrical and computer engineering senior lecturer Joe Skovira, PhD ’90, the student leaders (MEng candidate Kristin Lee and Smith Charles ’23) and their team designed a replacement control system, developed new software, and added redundancies for stability and backup.

Bill Nye chats about details of the solar noon clock with Smith Charles ’23, one of the engineering students who worked on the project to revamp the controller and its software
Nye chats with electrical and computer engineering major Smith Charles ’23. (Photo by Ryan Young / Cornell University)

They used off-the-shelf components and parts wherever possible—and documented everything they did, to inform any future fixes or updates.

By the time Nye—whose current work includes serving as CEO of the Planetary Society, the space interest group co-founded by Cornell’s own Carl Sagan—came to campus on March 15, it was up and running.

Cheers for a science celebrity

During the visit, the former mechanical engineering major was enamored with all aspects of the clock, its revamped control system, and the student team’s tweaks and plans.

Nye in front of a display case in the Rhodes Hall lobby that tells the intertwined stories of his father, sundials, and the clock.
Nye views a display case in the Rhodes Hall lobby that tells the intertwined stories of his father, sundials, and the clock. (Photo by Ryan Young / Cornell University)

He spent several hours with them on Rhodes Hall’s top floor and in labs; no detail escaped his attention as he pulled out his laptop to check schematics, original design documents, and calculations.

But he also was philosophical—pondering the clock’s longevity and its planned presence on the Hill for decades to come, as well as his own upcoming Reunion.

“That’s a feature of coming back to campus after 45 years—it’s [knowing] you’re gonna die,” he says wryly. “And so what you want in a gizmo like this clock on Rhodes Hall is for it to work for a long time. You want it to have a life like McGraw Tower. It’s venerable, it’s beautiful. It’s part of our history.”

And Nye’s big-picture thinking extends—as did Sagan’s—beyond our “pale blue dot” of a planet. He wants the clock not only to educate its observers, but to spark wonder for generations to come.

“I hope it gives you pause for thought about your place in space,” he said to the crowd that had gleefully followed him out to Hoy Field to watch the successful test.

“We’re on a planet going around a star and yet, we can figure that out—and that’s astonishing," he continued. "Something Carl Sagan said is that we are made of ‘star stuff,’ and yet we can understand this. So we are one way that the universe knows itself. Whoa!”

Top image: Surrounded by students delighted with his surprise visit on March 15, Nye watches for the moment that the clock indicates the sun's highest position in the sky. (Photo by Ryan Young / Cornell University)

Published: April 22, 2022


  1. robert reed, Class of 1968

    Essential for celestial navigation at sea in a tiny sailboat. Local noon sights were essential since they were the easiest to shoot and plot. But you do need a reasonably visible sun. Usually that occurs at least one day out of five; and traveling along at 6 knots( ~7mph), good enough in practical terms. Does the clock have an interactive feature so students can find their longitude?

  2. Richard C. Bareford, Class of 1972

    Centuries before the electronics existed for Nye’s clock, the meridian line was an accurate indicator of local solar noon. A properly sized and positioned hole in the roof of a large building projects the sun’s image upon the structure’s floor at midday. No lens is needed, the camera obscura principle serves the purpose. When and where the image crosses a north-south line inscribed on the floor not only marks noon but the date as well. Giovanni Cassini’s monumental meridiana completed in 1655 within the Basilica of San Petronio, Bologna, Italy, still functions like clockwork. Actually, it was better than the mechanical clocks of the time. People set their own timepieces by the church bells rung at the observed moment. Its official purpose was to fix the date of Easter, and unofficially provide evidence favoring Copernican heliocentrism. J.L. Heilbronn’s 1999 book, The Sun in the Church – Cathedrals as Solar Observatories, examines the history and design of meridian lines in great detail.

    Perhaps there is a suitable location on Cornell’s campus?

  3. Stephen Tauber, Class of 1952

    On the emigration from Vienna in 1938, after the German Anschluss, my family stopped in Milan. There, in the cathedral, my mother explained to 6-year-old me the function of the hole in the roof and the line on the floor in determining the time of the equinox.

    • Richard C. Bareford, Class of 1972

      What a great memory from a tragic time! There are also meridian lines in Florence, Palermo and Rome. Tests in 1976 confirmed that Milan’s line was able to fix noon within a second or two. Back in the day a functionary observing in the Duomo would pass the word to another in the tower of the Palazzo della Regione who would signal a third, stationed on the Castello Sforzesco, who would fire a cannon to announce noon.

    • Nikos Pitsianis, Class of 1997

      Even in the midst of uprooting and uncertainty for tomorrow, your mother found the opportunity to instill in a six-year-old that knowledge is precious and cannot be taken away!

  4. Roger Smith

    Love Bill Nye, the Science Guy! I’m a retired Science teacher now living on eastern Long Island. Great memories of Cornell!

  5. Mitch

    According to the video in the article, the spot on the clock “lights up” when the computer program tells the gates in the light tube to open. It is unclear to me how a viewer of the clock will know when it is the solar noon? Is it when the spot is brightest? If that’s true, why would you even need the gates in the tube?

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