Bloomington Township in Monroe County, Indiana — The American Midwest (Great Lakes)
Calabi-Yau Quintic Cross-Section
z15 + z25 = 1
Photographed by Daniel Barriball, June 18, 2026
1. Calabi-Yau Quintic Cross-Section Marker
This surface represents the 6D Calabi-Yau hyperspace given by the complex equation
The Calabi-Yau Quintic belongs to a family having non-trivial solutions to Einstein's equations in empty space. Such constructs play important roles in pure mathematics and theoretical physics. Explicit parametric expressions devised to reveal the underlying geometric structure of this class of complex surfaces were developed by Andrew J. Hanson at Indiana University in 1990.
Donated by Andrew J. Hanson and Patricia L. Foster
Realized by Sculptor William F. Duffy
2022
Erected 2022 by Indiana University.
Topics. This historical marker is listed in these topic lists: Education • Science & Medicine. A significant historical year for this entry is 1990.
Location. 39° 10.382′ N, 86° 31.354′ W. Marker is in Bloomington, Indiana, in Monroe County. It is in Bloomington Township. It is on North Forrest Avenue near East 11th Street, on the right when traveling south. This marker stands in the courtyard on the east side of Luddy Hall on the campus of Indiana University.
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Regionally, this marker is in Southern Indiana. It is also in the American Midwest and in the Corn Belt. Globally, it is in North America, the Western Hemisphere, the Western World, and the Anglosphere. Historically, it finds itself in what was once the territory of the Mississippian Culture and also the Northwest Territory.
Other nearby markers. At least 8 other markers are within walking distance of this marker: Collins Living-Learning Center (approx. 0.2 miles away); Original Memorial Stadium (approx. 0.2 miles away); Melanie S. Walker (approx. Ό mile away); Integrating Basketball (approx. 0.3 miles away); Ernie Pyle (approx. 0.3 miles away); Elinor Ostrom (approx. 0.4 miles away); The River Jordan (approx. 0.4 miles away); Memorial Pillar and Centennial Steps (approx. 0.4 miles away). Touch for a list and map of all markers in Bloomington.
Also see . . . Calabi-Yau sculpture is a visual force of nature. IU Luddy School of Informatics, Computing, and Engineering
Hanson(Submitted on June 28, 2026, by Daniel Barriball of Chesterton, Indiana.)has the expertise to make this happen. Hes an internationally renowned theoretical physicist whose work includes co-discovering the Eguchi-Hanson metric. His other research includes computer graphics, visualization of abstract concepts in math and physics, and virtual astronomy. His many versions of string-theory-adapted graphics have been used on TV shows, books, magazine covers and numerous string-theory articles. I make pictures of things no one has seen before, he said. The sculpture represents in many ways Hansons lifes work. This is so exciting, he said, its hard to express.Photographed by Daniel Barriball, June 18, 20262. Calabi-Yau Quintic Cross-Section Marker in context
Photographed by Daniel Barriball, June 18, 2026
3. Fermat Quintic Surface
This plaque is on the opposite side of the Calabi-Yau sculpture from the historical marker:
z15 + z25 = 1
This equation by itself is a Fermat Surface, a complex version of the real equation xn + yn = Zn of Fermat's Last Theorem fro the 17th century. This sculpture is a projection of the Fermat Quintic Surface livng in four dimensions to our 3D physical world. The related real curve x15 + x25 = 1 outlines the scupture's base.
25 copies of the same hexagonal surface patch, distorted by the projection, combine to build the sculpture's entire surface. The five warped outer rings each collapse to a distinct point at infinity, completing a closed surface. 5-fold symmetries related to the fifth power appear throughout.
A Puzzle: Assuming the outer end of each marked edge terminates at one of the five points at infinity, count the number of verticies, edges, and faces. What are the Euler characteristic and genus of the Fermat Quintic Surface?
25 copies of the same hexagonal surface patch, distorted by the projection, combine to build the sculpture's entire surface. The five warped outer rings each collapse to a distinct point at infinity, completing a closed surface. 5-fold symmetries related to the fifth power appear throughout.
A Puzzle: Assuming the outer end of each marked edge terminates at one of the five points at infinity, count the number of verticies, edges, and faces. What are the Euler characteristic and genus of the Fermat Quintic Surface?
Photographed by Daniel Barriball, June 18, 2026
4. Calabi-Yau Sculpture
Luddy Hall is the building in the background.
Credits. This page was last revised on July 9, 2026. It was originally submitted on June 28, 2026, by Daniel Barriball of Chesterton, Indiana. This page has been viewed 21 times since then. Photos: 1, 2, 3, 4. submitted on June 28, 2026, by Daniel Barriball of Chesterton, Indiana. • Devry Becker Jones was the editor who published this page.
