Cloudy skies broke just long enough Monday afternoon for Austin College to celebrate the fall equinox and with its annual light show.


Students and staff gathered in the atrium of the college’s IDEA Center at precisely 1:18:40 p.m. to watch as the sun’s light entered through a specially-designed hole in the building’s roof and crossed onto a floor marker denoting the sun’s highest position in the sky — solar noon.


“Equinox means equal nights,” and it turns out, that on this particular day, theoretically, we should have an equal number of night hours and an equal number of daytime hours —12,” Austin College Professor of Physics and Adams Observatory Director David Baker said.


Because earth’s atmosphere has a tendency to distort sunlight, this year’s equinox actually occurred several days ago. Nonetheless, Baker said the technology that allowed them to follow the sun’s movement inside the building Monday has been relied upon for centuries of scientific and religious study.


“The gnomon hole and the meridian line would provide information about the path of the sun through the sky or — in modern terms — the rotation of the earth and the seasons,” Baker said. “Gnomon holes were found in Roman Catholic cathedrals in Western Europe and helped the Church determine when the equinox was and when Easter could be celebrated.”


Though the much-anticipated beam of light danced only briefly before observers, Baker said the phenomenon always draws a crowd and remains remarkably accurate in helping humankind determine its place in time and space.


“This solar observatory clock is more accurate than the timepiece that you’re probably wearing, because all it depends on is the location of the sun in the sky,” Baker said.


And fortunately for students, Monday’s celebration ended just in time for the their next classes.


Drew Smith is a reporter for the Herald Democrat. Contact him at asmith@heralddemocrat.com.