This is the third lecture series of my complete online introductory undergraduate college course. This video series was used at William Paterson University and CUNY Hunter in online classes as well as to supplement in-person course material. Notes and links are present in the videos at the start of each lecture. 0:00:00 - lecture 1: Faraday, Maxwell and the Aether 0:14:51 - lecture 2: The Speed of Light and the Michelson Morley Experiment 0:33:06 - lecture 3: The Great Relativistic Conundrum 0:50:09 - lecture 4: Special Relativity's Implications 1:06:40 - lecture 5: Special Relativity in Detail 1:33:55 - lecture 6: General Relativity's Reason to Exist 1:53:03 - lecture 7: General Relativity Curvature and Tests 2:23:51 - lecture 8: General Relativity and the Bending of Light's Path 2:42:20 - lecture 9: General Relativity and the Slowing of Time by Gravity 3:05:21 - lecture 10: The Tides 3:15:16 - lecture 11: Faster Than Light Tachyons, Causality and Tacos In this lecture series, we start with Michael Faraday and James Clerk Maxwell finalizing and culminating the wave theory of light. Faraday gives us our best picture of how light "looks" and Maxwell gives us the four equations that unify electricity, magnetism and light. Also, we check in on Hershel's discovery of infrared, and other wavelengths of light. Next, we ask what is the speed of light? What do the waves of light travel in? What do we know about how light gets here from there? The answers are even more puzzling. In this one, we learn that the waves of light can still be waves, even if they don't actually "wave" anything. Nature starts to show us just how strange she is. Third, we check in on an oddity. Once upon a time, there was classical physics. It had Galilean Relativity, Newtonian Mechanics and Maxwell's Laws of Electromagnetism. But, these three things, while wildly successful, did not fit together at all. Let's see why. Next, we chat about the postulates of Special Relativity, and three of its main implications: desynchronization of clocks, time dilation and length contraction. Then we detail the effects of time dilation, length contraction and clock desynchronization. We also chat about muon decay which demonstrates this effect. In the next lecture, General Relativity arises out of our need to reconcile the issues of Newtonian Gravity. It has some problems that only rethinking Gravity can solve. After this, we start to see why General Relativity is one of the most successful theories of Physics. It helps us give a mechanism to gravity, and allows for testable predictions. We'll chat about the Correspondence Principle, The Equivalence Principle, intertial versus gravitational mass, and the nature of spacetime curvature and how it's measured. Overall, the segment emphasizes clear definitions, underlying geometry, and practical observing guidance so viewers can connect the concept to the real sky.