Where Science and Jazz Combine – What happens as one tries to travel at the speed of light? Einstein’s theory predicts that time will slow down for a given object with mass as it approaches the speed of light, though it can never quite reach it. But what about light itself? Light particles, known as photons, have no mass and travel at the speed of light. Unlike us human beings, time does not flow for photons. Imagine a photon, generated during the Big Bang, flying through the expanding universe to reach our eyes. While scientists would say that this journey took 13 billion years, for that traveling photon, it took no time at all—everything happened at once. In quantum optics, we observe multiple phenomena that seem indifferent to the flow of time. In this seminar, we will explore the arrow of time within the context of quantum interferometry, a technique used as a sophisticated stopwatch for photons—a method of timing light using light itself. We will pose a seemingly simple question to our photon: When did you arrive? The answer, however, is more complex than it seems, revealing how photons often defy our intuition and challenge our understanding of the physical world.