# Comment on the Origin of the Equant Papers by Evans, Swerdlow, and Jones

@article{Duke2005CommentOT, title={Comment on the Origin of the Equant Papers by Evans, Swerdlow, and Jones}, author={Dennis W. Duke}, journal={Journal for the History of Astronomy}, year={2005}, volume={36}, pages={1 - 6} }

1. determined the apparent value of 2e, the distance between the Earth and the center of uniform motion around the zodiac, corresponding to the zodiacal anomaly. One can use a trio of oppositions, some other procedure based on oppositions (e.g. Evans), or in principle, any synodic phenomenon, but in practice oppositions would be the clear observable of choice. 2. determined the apparent value of e , the distance between the earth and the center of the planet’s deferent, by looking at some…

## 4 Citations

The Philosophical Justification for the Equant in Ptolemy’s Almagest

- Physics, Philosophy
- 2017

In this paper I offer a close reading of Ptolemy’s philosophical defense of the equant in Almagest 9.2. I identify the challenge to the equant that his defense is supposed to meet, characterizing it…

Preface

- BusinessRAIRO Theor. Informatics Appl.
- 2005

This monograph presents the new developments in multi-level (in particular bilevel and tri-level) decision-making theory, technique and methodology in both modelling and solution issues and shows how a decision support system (software) can support managers in reaching a solution to a multi- level decision problem in practice.

Ptolemaic planetary models and Kepler’s laws

- PhysicsArchive for History of Exact Sciences
- 2018

Abstract
In this article, we aim at presenting a thorough and comprehensive explanation of the mathematical and theoretical relation between all the aspects of Ptolemaic planetary models and their…

Current Bibliography of the History of Science and Its Cultural Influences, 2006

- Isis
- 2006

692. RASHED, Roshdi, and Christian HOUZEL. "Thabit ibn Qurra et la theorie des paralleles." Arab. Sci. Phil. 15 (2005): 9-55. 693. RASHED, Roshdi. Oeuvre mathdmatique d'alSijz. Volume I : Gdometrie…

## References

SHOWING 1-10 OF 11 REFERENCES

On the Greek Origin of the Indian Planetary Model Employing a Double Epicycle

- Physics
- 1971

The development of geometric models to explain the inequalities of planetary motion in terms of combinations of circular motions is characteristic of Greek astronomy, and derives its initial bias…

The Empirical Foundations of Ptolemy's Planetary Theory

- Physics
- 2004

In beginning his consideration of the theory of the planets in Almagest 9.2, Ptolemy states that, just as he has already done for the Sun and Moon, he wishes now to show that the apparent, irregular…

The History and Practice of Ancient Astronomy

- Physics
- 1998

Preface 1. The Birth of Astronomy 2. The Celestial Spheres 3. Some Applications of Spherics 5. Solar Theory and Time Reckoning 6. The Fixed Stars 7. Planetary Theory Bibliography Appendix: Patterns…

On the function and the probable origin of Ptolemy's equant

- Physics
- 1984

We examine the roles of the equant point and the eccentric deferent circle in Ptolemy’s planetary theory. The necessity of these features of the model is demonstrated empirically by a study of the…

The equant in India: The basis of ancient Indian planetary models

- Archive for history ofexact sciences, i
- 1961

The Paitamahasiddhanta of the Visnudharmottapurana

- Brahmavidya, xxxi-xxxii
- 1967

The Paitamahasiddhanta of the Visnudharmottapurana", Brahmavidya, xxxi-xxxii

- Aryabhatiya ofAryabhata (New Delhi,
- 1976

A route to the discovery of non-uniform planetary motion

107-121 made the original suggestion and offered a justification based on a power series analysis

- Aryabhatiya of Aryabhata
- 2004