Hell Is Empty. The Thirty Years' War Has Begun *
The King of Bohemia, Ferdinand the 2nd, is unhappy with previous kings who have granted religious freedom to the Protestants. Protestants are even building chapels on the King's own land. King Ferdinand is the designated heir to the Holy Roman Emperor, so whatever he wants today has sweeping implications for Europe's future. Representatives of the King have arrived in Prague to read the riot act to the Protestant representatives. In summary: the lives of the Protestants are forfeit and all that is left to do is the dying. The Protestants listen carefully, and realize that if they are going to die anyway they might as well die as lions. Two of the King's men are led out of the room because they seem like well-meaning fellows. The other King's men are led out of the room too... via the window. They fall three floors to the pavement, and live. The Catholics call it a miracle, but the Protestants say... well... it no longer matters what anyone said. The point is that the King is giving a war and the Protestants have sent their RSVP. The Thirty Years' War is on.     
Kepler's 3rd Law of Orbital Dynamics
I know what you are saying to yourself... "The square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit. It's so obvious!" Look. I know that Kepler's 3rd law of orbital dynamics is probably printed on the back of every cereal box today, but back in the 17th century, astronomers used to think that all planetary orbits were perfect circles centered on the Sun and that orbital speeds were constant. Planetary orbits are none of those things. Orbits are ellipses which means they are ovals which have TWO off-center focal points. So the Sun can't be in the center of the orbit. It must be at one of the focal points of the ellipse. Since an elliptical orbit means a varying distance from the Sun, the speed of a planet will vary within a range. Given the instrument precision of the time, they can see the difference, but just barely. 
This Year on Wikipedia
Year 1618, Wikipedia.
- * The asterisk in the section header indicates that it was read on the podcast.
- 30 years war - definition of 30 years war (2015). Retrieved on 4 August 2015. “A series of wars in central Europe beginning in 1618 that stemmed from conflict between Protestants and Catholics and political struggles between the Holy Roman Empire and other powers. It ended with the Peace of Westphalia (1648).”
- The Reader’s Companion to Military History. History.com. Houghton Mifflin Harcourt Publishing (1996). Retrieved on 4 August 2015. “The fallout reshaped the religious and political map of central Europe, setting the stage for the old centralized Roman Catholic empire to give way to a community of sovereign states.”
- The Tempest - Wikiquote. en.wikiquote.org (2015). Retrieved on 4 August 2015. “Then all afire with me: the king's son, Ferdinand, With hair up-staring, -- then like reeds, not hair, -- was the first man that leapt; cried 'Hell is empty, And all the devils are here.' -- Ariel, Act 1, Scene 2”
- Defenestrations of Prague - Wikipedia (2015). Retrieved on 4 August 2015. “The first occurred in 1419 and the second in 1618, although the term 'Defenestration of Prague' more commonly refers to the later incident. Both helped to trigger prolonged conflict within Bohemia and beyond. Defenestration is the act of throwing someone or something out of a window.”
- Alex Shrugged notes: The phrase "Hell is Empty" comes from Shakespeare's play, The Tempest. Fernando, the son of the king, shouts "Hell is empty, and all the devils are here!" and then throws himself into the ocean.
- The Consequences and Effects of the Thirty Years War. articlemyriad.com (December 7, 2011). Retrieved on 4 August 2015. “To fully understand modern history, it is important to comprehend the full effects of the Thirty Years War. The end of the Thirty Years War produced a number of dramatic consequences and altered Western Europe in significant religious, political, and social ways. Generally speaking, the post-war period produced the dissolution of the Holy Roman Empire and the subsequent fall of the Hapsburg powers. The later divisions that occurred made Europe more like it is now with the Catholic areas in the south and the Lutherans farther north and more importantly, it took the central power from the Catholic Church.”
- Kepler's laws of planetary motion - Wikipedia (2015). Retrieved on 5 August 2015. “The square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of its orbit.”
- Philosophiæ Naturalis Principia Mathematica - Wikipedia (2015). Retrieved on 5 August 2015. “The Principia states Newton's laws of motion, forming the foundation of classical mechanics, also Newton's law of universal gravitation, and a derivation of Kepler's laws of planetary motion (which Kepler first obtained empirically). The Principia is 'justly regarded as one of the most important works in the history of science'.”