Sheikh Bahai

Sheikh Bahai (1547-1621 AD) was a scholar, philosopher, architect, mathematician, astronomer and poet in 16th century Iran. He was born in Lebanon and migrated in his childhood to Safavid Iran with his father. He wrote 88 books on philosophy, logic, astronomy and mathematics. He had Sufi leanings, often dressing like a Dervish and joining Sufi circles, specifically the Nurbakhshi and Nimatullahi Sufi orders.

He was one of the main founders of the Isfahan School of Philosophy and drove the design of several monuments such as Monar Jonban (Shaking Minarets) in Isfahan. He was also an expert in topography, directing the water of the Zayandeh River to different areas of Isfahan and designing a canal called Zarrin Kamar which is one of Iran’s greatest canals.
He also constructed a furnace for a public bathroom which was open to the public until 20 years ago. Interestingly, the furnace was warmed only by a single candle, which was placed in an enclosure, warming the bath’s water. For centuries, the unsolved mystery of the bath preoccupied scientists around the world. Known as the “mysterious bath” because it was warmed without the use of a direct energy source, the heating system was considered an engineering masterpiece.

When recently repair work was done in Sheikh Bahai’s house, clay pipes and connected wells were discovered on the floor of a building next to it, shedding light on where the energy of the candle comes from. Archaeological studies revealed that the sewage system in Isfahan was connected to the bath through pipes.
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Scientists have said that the heat stemmed from its water container (boiler) which is made of gold,, which is a perfect conduit of heat and electricity, generating vast amounts of energy with low amount of heat. As to why Sheikh Bahai refused to reveal the secrets of the bath’s heating system, some say it might have been due to concern about thieves attempting to steal the gold in the bath had they known about it. 

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Sources:

• Iran Front Page. "A burning candle, a hot bath; connect the dots." June 7, 2015.
• Iran Review. "Sheikh Bahai Prominent Scholar of Safavid Era." April 24, 2010.
• Wikipedia. "Bahāʾ al-dīn al-ʿĀmilī." CC BY SA 3.0.