John L. Heilbron The Sun in the Church

J. L. Heilbron
Harvard University Press (April 2, 2001)

The 2001 book with its 384 information packed pages is a fundamental addition to the library of anyone interested in the vast field of Space Theology.

It defines by its contents and methodology what good Astrotheology should be. It does this by giving a penetrating, scientifically and historically accurate case study that demonstrates the importance of astronomy to the religious man in a concrete real life situation.

Space Theology deals with our evolving world views in the time of space exploration and enormous advances in astronomy and can easily become overly theoretical. As it studies our understanding of life on planet Earth and our attitudes and belief systems in communities of believers or unbelievers, Astrotheology may become rather futile exercise in speculations while expressing our faith or lack of it  in God of Israel, the Creator of the Universe.

By tying mathematical, physical, astronomical data about the Sun with the historical reality of the Church, professor Heilbron avoids such a speculative and at the end rather fruitless line of argumentation and gives useful and significant  facts for understanding ourselves, our belief systems and the Cosmos.

Soli Deo Gloria!


Steven J. Harris, from review in American Scientist

"Displaying an easy familiarity with an astonishing array of primary and secondary sources, Heilbron weaves into the main story line subplots of contending egos and ideas, civic pride, aristocratic patronage and the Catholic Church's endeavors to retain cultural prestige and scientific authority in the wake of the trial of Galileo. His sensitivity to the cultural climate in which cathedral-observatories arose and operated leads him to several conclusions that many readers may find startling."

Ingrid D. Rowland,from review in The New York Review of Books

"Heilbron's study is unabashedly mathematical, filled with diagrams and equations (.....) The innumerate reader will learn much from Heilbron's book, and may come away with a different appreciation of the stars above us." 

Church as a Sun observatory
A Guide to Heilbron's Sun in the Church

Rick Hunter, from review in amazon.com
"J.L. Heilbron's The Sun in the Church: Cathedrals as Solar Observatories is a beautifully illustrated, finely written exposition of how the Roman Church used sacred space to perform astronomy.

The most sacred day in the Church calendar is Easter, established as the Sunday after the first full moon after the vernal equinox. As it turns out, this was an astoundingly difficult day to calculate, especially years in advance. As a result, in the Middle Ages the celebration of Easter "drifted" from the true date; the Church found itself commemorating Christ's resurrection on the "wrong" Sunday, a matter of grave concern.

To solve this problem, astronomers determined that large buildings - most ideally churches themselves - could be made into solar observatories with a light opening at the apex and a meridian line placed on the floor. By this device, Church-supported scientists could observe the sun's precise position and movement with reference to the meridian line, and thereby make needed Easter (and other) calculations." /div>

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