In spite of five decades of intensive observational effort across the electromagnetic spectrum, some of the most critical questions regarding relativistic jets remain unanswered, including how the jets are launched and the composition of the jets. Since 2008 we have been monitoring ~1800 blazars at 15 GHz, with the 40 m Telescope of the Owens Valley Radio Observatory, to address these questions. Now, with the advent of neutrino astronomy, a new avenue of attack has opened up. I will review the status of the search for neutrino-blazar associations and describe the unique role that the 40 m Telescope is playing in this area. In another multimessenger program, I will describe the discovery of the remarkable supermasssive black hole binary candidate, PKS 2131-021, and the unanticipated phenomenology it has presented. I will also review the status of our Symmetric Achromatic Variability gravitational lensing studies of PKS 1413+135. Finally, I will describe how the 40 m Telescope monitoring program led to the RoboPol program and the wide area linear optical polarimeter programs in Crete and South Africa, to determine the Galactic magnetic field through observations of the optical polarization in over 4 million stars over two-thirds of the sky.
To view this talk via YouTube, please visit: https://www.youtube.com/playlist?list=PLb1880Rn0qkKzIavl-n_7RaMyDOiU9XHm