Journey to Totality by Dr. Avery Archer


On Monday, Feb. 12, Assistant Professor of Physics and Astronomy Dr. Avery Archer hosted a talk called Journey to Totality, which detailed the scientific explanation behind the solar eclipse. He also included information on the resources DePauw will provide students leading up to the eclipse. On April 8 at around 3 p.m., our world will be viewed as dark as nighttime, and we will even be able to see some stars. The months leading up to this event have some interesting and fun events sponsored by the DePauw Physics Department and the McKim Observatory that students might be interested in. This includes multiple talks throughout the month, student-created poetry and music, eclipse trivia, and a Spotify playlist with eclipse-themed music. However, to understand this unique event taking place, Dr. Archer explained the science behind the eclipse to around 100 people online and in person.

“Eclipses are actually remarkably simple,” he said to begin the talk. Eclipses occur when there is a blockage of light by the moon. However, eclipses happen pretty frequently. So what makes the April 8 eclipse unique? Totality, he says. Totality occurs when there is a complete blockage of light as much as 50 miles wide on the Earth’s surface. Totality is so unique for a location that Dr. Archer cited the last one occurring in Greencastle, “over 100 years ago and the next event occurring in 2153.” With a small path of totality across the southern and midwestern United States, he also explained that Greencastle could be a popular destination with “hundreds of thousands of people traveling to somewhere in the path of the eclipse.”

To teach students, faculty, and guests more about eclipses, Dr. Archer also explained the different types of eclipses. The three types of eclipses are Total, Annular, and Partial. Total eclipses occur during the complete blockage of sunlight. Annular eclipses occur when there is partial coverage of sunlight due to the moon not completely covering the sun as it changes distances from Earth throughout its cycle. The Partial eclipse occurs when there is a partial blockage of sunlight, which appears as a crescent sun instead of a circle of light like the Annular eclipse.

On the day of the eclipse, we will see “first contact” as Dr. Archer called it, at around 1:49 p.m. as the moon slowly begins to cover the sun. Finally, we will see the “diamond ring,” which is the last bright spot, coming through the final valley of the moon and will appear extremely bright, says Dr. Archer. Totality will then occur at 3:08 p.m. and will last for just over three minutes.

Multiple telescopes with special solar filters will be provided by the DePauw Physics Department so individuals can view the sun before, during, and after the eclipse. Viewing glasses will also be provided for students to view the eclipse. Because of the gravity of this occasion, classes will also be canceled that afternoon.

Dr. Archer strongly encourages students to take the event in and enjoy it because of how incredible and rare a total eclipse is for anybody in the world to experience. Finally, he wanted to let the universe know he is, “really, really hoping for clear skies.”

You can visit the DePauw DeClipse webpage here for more information.