[1] Coming from Seleucia on the Tigris, Mesopotamia, the capital of the Seleucid Empire, or, alternatively, Seleukia on the Erythraean Sea,[2][3] he is best known as a proponent of heliocentrism[4][5][6] and for his theory of the causes of tides.
Seleucus is known to have supported the heliocentric theory of Aristarchus of Samos, which stated that the Earth rotated around its own axis which in turn revolved around the Sun.
Seleucus correctly theorized that tides were caused by the Moon, explaining that the interaction was mediated by the pneuma.
[11] Seleucus is known from the writings of Plutarch, Aetius, and Strabo, all of whom were Greeks, and the Persian Muhammad ibn Zakariya al-Razi.
It is possible that the astronomer Seleukos lived or was born in this city, but it is also possible that his native town was Seleukia on the Erythrean Sea.