(This is the first article in the column “Religious Scientists of the Catholic Church” which looks at the lives and contributions of prominent vowed religious scientists.)
The year 2018 marked the 200th anniversary of the birth of Fr. Angelo Secchi SJ, and so there have already been several articles on Fr. Secchi in this blog. An interested reader could review any of these articles:
“Ghost of elements, spectres of the universe: Angelo Secchi SJ” by Michelle Francl, Aug 8, 2018.
“Solar Prominences and a Prominent Jesuit Astronomer” by Robert Macke, Oct 23, 2018.
“Happy Birthday to the Father of Astrophysics!” by Guy Consolmagno, June 28, 2018.
And outside the blog, here’s another article I wrote about Secchi’s oceanographic studies:
For the YouTube generation, here is a video to watch:
Why begin this series with a scientist for whom so much has already been written? Why not start with someone else? One motivation is to strike while the iron is hot--while the name Secchi is still somewhat familiar to readers. But more importantly, he made so many contributions in so many different fields, and yet he is almost unknown to the world today.
With anticlericalism very strong in Italy at the end of the 19thcentury, his status as a priest and his connection to the Vatican were reason enough to suppress his memory and scientific legacy. On top of that, his rivalry with Norman Lockyer (the founder of the journal Nature) led to none of his works being published in English.
This is a legacy that needs to be resurrected. In my opinion, the name Secchi should be a household term alongside Newton, Kepler, and Galileo.
Secchi also makes a great starting point because the connection between his scientific work and his religious life is explicit. He was the director of the observatory of the Roman College, which was the Papal observatory of his day, thus making him "the Pope's astronomer." During his tenure as director, he had the observatory moved to a more stable platform: the roof of the church of Saint Ignatius. One could say he literally built his scientific work upon the foundation of the Church!
Because there is already much content available on this blog regarding Fr. Secchi, I will skip his biographical sketch and try to keep the rest of this entry short. Here is a summary of some of his scientific contributions:
Astrophysics: He was one of the first to systematically study the spectra of stars. He made spectroscopic observations of over 4000 stars and classified them by type. This early work was the foundation upon which the Harvard Observatory built the spectral classification system that we use today.
More importantly, Secchi was one of the few astronomers of his day who tried to understand the physical nature of stars at a time when astronomy was concerned with measuring their positions and proper motions. He attempted to identify and quantify the presence of chemical elements such as helium and carbon in starlight.
Solar Physics: Secchi made myriad observations of the Sun in diverse ways. He took spectra of the solar atmosphere, corona, and prominences. He made numerous observations of sunspots. During eclipses, he photographed solar prominences. When compared with photos taken by collaborators separated by hundreds of kilometers, the photographs matched, thus confirming that prominences are a real solar phenomenon and not an illusion due to atmospheric effects.
He published his work in a book Le Soleil (1870), which quickly became the European standard for solar astronomy and was translated (from the original French) into German and Italian. (As mentioned previously, his work was never translated into English.)
Planetary Science: Secchi was among the first to examine planets as other worlds to study. He took spectra of the atmospheres of many of them. He viewed Mars through the telescope and noted its surface features. He corresponded with the famous astronomer Giovanni Schiaparelli, who adopted his use of the term “canali” for dark channel-like Martian surface features.
(This later became mistranslated as "canals" by the American astronomer Percival Lowell, who imagined a dying Martian civilization constructing globe-spanning engineering works to bring scarce water to their cities. This idea became popularized in the John Carter series of books by Edgar Rice Burroughs. The idea of water-bearing "canals" finally was put to rest with the visit of the Mariner 4 spacecraft in 1965.)
Terrestrial Magnetism: In 1853, Secchi established the first geomagnetic observatory in Italy. He had a laboratory constructed with several instruments for measuring the strength and direction of the Earth’s magnetic field and how it varies with time. He made connections between variations in the field and various and solar activity. The legacy of his research lives today in the study of “space weather.”
Meteorology: Secchi was interested in atmospheric physics and the connection between atmospheric phenomena and other phenomena, such as solar activity. He invented a device, called the “meteorograph,” to measure and record several relevant parameters for this study.
He also developed a network of weather stations throughout Italy, connected by telegraph. This network was nationalized by the Italian government in 1876.
Geography: Secchi conducted a geodetic survey of the via Appia Antica, one of the main roads leading to Rome and an important base for many of the maps of Italy of the day.
Oceanography / Limnology: At the invitation of Commander Alexander Cialdi of the Pontifical Navy, aboard the corvette Immacolata Concezione, Secchi carried out experiments on the measurement of the clarity of ocean water. He lowered brightly colored disks into the water until they were no longer visible, and developed a standard for this measurement and its interpretation. Even today, water clarity is assessed by lowering bright white or black-and-white disks—called “Secchi disks”—into the water.