He was admitted to the National and Kapodistrian University of Athens, from which he received his Degree in Physics in 1971 (Class of 1970).

After receiving his Ph.D., Seiradakis moved to Germany as a postdoctoral fellow at the Max Planck Institute for Radio Astronomy (MPIfR), working under Prof. Richard Wielebinski.

Together with Dr. W. Huchtmeier and others, he performed a comprehensive survey of the neutral hydrogen distribution in nearby galaxies[18][19][20] using the 100-m radio telescope at Effelsberg.

In 1984, together with collaborators A. N. Lasenby, F. Yusef-Zadeh, R. Wielebinski and U. Klein, Seiradakis performed some of the first polarimetric observations of Sag A* at 10 GHz.

This study revealed an extended polarised radio source with jet-like lobes originating from the Galactic Center.

As a faculty member, he contributed in numerous fields, including neutron stars (pulsars), neutral hydrogen modelling in nearby galaxies, the Galactic Center, Flare Stars, Lunar Transient Phenomena and Archaeoastronomy.

However, in the early 2000s, a new effort to analyse it using more advanced imaging techniques commenced, the so-called "The Antikythera Mechanism Research Project"[24] (AMRP).

Prof. Seiradakis led the Greek involvement in this effort, along with Prof. Xenophon Moussas and Yannis Bitsakis.

The project's findings have been presented in a series of scientific papers[2][25][26] and are summarised in a review article in Nature entitled, "Our current knowledge of the Antikythera Mechanism"[1] by J.H.

[17] Through his teaching and outreach activities, Seiradakis played a central role in the development of astronomy in Greece during the entire period of the Third Hellenic Republic.

Dozens of his students have continued their studies at the postgraduate level in astrophysics and went on to assume faculty research positions, both in Greece and abroad.