Surya Tilak at Ram Temple and the State of Science
Gautam Menon | 2 May 2024 | The Indian Express
The Surya Tilak project at the Ram temple in Ayodhya has been the subject of recent public interest. It involved constructing a mechanism to direct sunlight onto the forehead of the idol. This was to first happen at noon on April 17, the occasion of the festival of Ram Navami this year. The mechanism was to be designed so as to repeat its task every year on the festival date.
The difficulty is that this festival follows a lunisolar calendar. Purely solar or purely lunar calendars follow the motion of the sun or the moon respectively. Special festival dates, if they follow a solar calendar, are the same each year. However, if such festival days are at all tied to the phases of the moon, they will fall on different calendar dates each year.