Nature of Light

Introduction

What we call light is the “Messenger” that gives information about objects that are at vast and even at extreme distances, and by far most of what astronomers know today about the Universe, is extracted from this source that we call light. Whether you use your eyes to look up at the night sky or whether you use the most advanced telescopes, it is LIGHT that is the messenger telling us about what generates that light.

In this seminar we talk about the voyage of humankind in understanding what light actually is. And even today, it may not be what you think.

This seminar is split into three parts:

1. A short history of Light.
This takes you through the history of what humans thought of the phenomenon of light and also of vision, starting in the classical Greek era. We end this first part with the famous Maxwell equations. 
2. Spectroscopy.
This continues the historic overview  with the discovery of the so-called Fraunhofer lines and how that led to the very important technique of spectroscopy. That history logically brings us to the discovery of the quantum nature of light, followed by the mathematical explanation of the electron energy levels in atoms, that surprisingly, brought Niels Bohr back to the Fraunhofer lines.
3. A Modern View of Light.
This provides a link to the modern view of light in the context of the development of Quantum Mechanics. We will see how the famous (or notorious) wave-particle duality has been resolved and how in the new physics we must accept the dual nature of light as well as of fundamental particles.

Find the Course Booklets of this seminar here.
Part 1 here.
Part 2 here.
Part 3 here.

Part / Episode	Description
1. Short History of Light
Episode 1	Early history of understanding light.
Episode 2	Towards the modern scientific era.
Episode 3	Electromagnetism and a conumdrum that Maxwell left behind.
2. Spectroscopy
Episode 1	Discovery of spectral lines.
Episode 2	Towards a major discovery.
Episode 3	Model of the atom.
3. Modern view of Light
Episode 1	Further confirmation of the photon model.
Episode 2	Wave-particle duality.
Episode 3	Experimental verification. Concluding remarks.