Clouds covering the sun parted just in time Friday afternoon for Austin College’s annual celebration of the autumnal equinox.

The event was held in the school’s IDEA Center and drew students and staff, who eagerly waited for the sun’s light to pass through a specially-designed passage in the building’s roof and onto a floor marker denoting solar noon — the sun’s highest position during the day.

“I can’t begin to tell you how satisfying it is to see this image of the sun hit the equinox marker right in the middle,” Austin College Professor of Physics and Adams Observatory Director David Baker said.

Baker said, by definition, an equinox is when a 24-hour period sees equal amounts of daytime and nighttime. But the professor explained that the name was slightly misleading.

“It turns out, that’s not exactly right,” Baker said. “Today, the fall equinox, the day is still a little bit longer than the night. That’s because the sun, even though it might be on the horizon, that light passes through the atmosphere. The atmosphere acts like a lens and actually bends it (the light), so we see a little more daylight than we should. Technically speaking, the equal day and night is going to be in a few days.”

While students and staff will have to wait a few days for the actual equinox, Baker said the technology that allowed them to track the suns movement inside the building has been accessible for hundreds of years and was developed not for scientific purposes, but for a religious one.

“The Roman Catholic church needed to know exactly when spring equinox would occur,” Baker said. “The reason why? Easter falls on the first Sunday after the first full moon, after the spring equinox. So in order to celebrate Easter, one must know when the spring equinox occurs.”

What designers came up with was the strategic installation of a small hole that allowed sunlight to penetrate a church or building and land on the north-south meridian to mark the different annual solar milestones. These include the summer and winter solstices and the spring and autumnal equinoxes.

“This is, in effect, an ancient camera and it produces an image of the sun,” Baker said.

Freshman and East Asian language studies major Elizabeth Munns attended the AC equinox celebration for the first time Friday. She said she was pleasantly surprised to see a familiar symbol where the autumnal equinox was marked on the floor.

“I was in a Chinese course and that symbol there is the Chinese symbol for both sun and day,” Munns said, pointing to the rectangular shape. “It’s cool to see something you’ve studied or learned used to mark something like this out in the real world.”

Other symbols present along the meridian line included the Greek and Mayan symbols for the sun. Munns said she enjoyed her first equinox celebration and appreciated how something as simple as a beam of light and an informed perspective could make her think about a phenomenon celebrated over the centuries by different cultures.

“This building is always here and the sun moves through it every day and it’s always hitting somewhere on the calendar,” Munns said. “But you never really notice it or appreciate it until it’s brought to your attention. It’s nice when things like this are brought up and you get a moment to recognize your place in the world as a human.”