HomeArticlesHistory of Space Travel – Looking to the Stars – Extra History – #1
History of Space Travel – Looking to the Stars – Extra History – #1
November 8, 2019
On the plains of Britain, a man stands looking to the heavens. Soon, his whole tribe will drag great stones here, to mark the passage of the days. Meanwhile, in Central America, a Mayan scholar observes the moon. Suddenly, realization dawns: the cycle of the moon repeats every 18.6 years! Soon, they’ll create the first lunar almanac. In China, an astronomer stares directly at the blinding sun. Laboriously and carefully, he records sunspots for the first time in human history. And, a priest stands on a ziggurat in ancient Babylon, gazing into the night. In his hand, a tablet. And on it, cuneiform. With it, he will use mathematics to unlock the secrets hidden in the sky. There’s one thing that all humanity shares: We all look to the stars. ♫ Music: Birth of the People ♫ Real quick before we continue: we wanted to thank the folks at Digital Extremes for sponsoring this series. Like many of us, the infinite possibilities of space inspired them and it helped shape their design of Warframe: the quintessential, space-faring, free-to-play co-op shooter (that you can, and totally should, check out in the link below). And they asked us to share humanity’s journey to the stars, from its first halting steps to the technologies the future might bring, in hopes that it inspires that same passion in all of you. Thanks D.E. On to the show. At first, the celestial bodies were gods and the heavens were just that: heavens. Understanding them served one purpose: divination. The augury of the stars spoke to the rise and fall of kings, or the displeasure of the deities. And so understanding them was a vital service, or so scholars and priests would tell kings. Thus, astronomy became the first truly state-funded science. Though in many places, it wasn’t a science as we understand it. Cosmology, religious beliefs, and symbolic interpretation played as much of a part in most early astronomy as empirical study did. And what astronomy there was, was really just in service of astrology. But then, something incredibly useful was discovered all across the globe: Studying the stars could help you keep track of time! Having a calendar was powerful, for everything from agriculture to politics. It let you know when to begin planting, and it let kings tell the world how long they’ve ruled or when their greatest victories took place. And so, astronomy evolved. Now, that’s not to say that it lost its elements of superstition, but especially in Babylon, where bureaucracy and civil administration had started to grow, very accurate records of celestial observations began to take place. And this was followed by the application of mathematics to better understand and predict the movement of the stars. But even as Babylon fell into decline, another state began to rise: one that loved a very special form of mental exercise: Geometry! This state was of course Greece! Granted, it wasn’t a state like any modern states. Rather, it was more like a hodgepodge of rival cities that often had little more than a language in common. However, for all of their antagonism, some things they did share were scholarship and intellectual pursuits. And it was with wonder that they looked up and saw the most complicated geometrical puzzle ever created hanging above them every night. So naturally, they took to applying geometry to astronomy and began the first real breakthroughs into what we might think of as astronomy today. But in a way that might seem odd to us in the modern world. Because, to the ancient Greeks, geometry was not only a form of mathematics, it also held mythical and philosophic properties. Which led them to believe that everything in the heavens could only move in perfect circles. This caused a huge problem with something called “Retrograde Motion”. You see, if you look up night after night and track the motion of a planet like Mars, it’ll appear to move east compared to the stars. But, for a few months out of the year, it’ll seem to move backwards to retreat west across the sky. Why? Well as we know today, it’s basically when the earth laps it. So imagine the Earth and Mars as two race cars. Earth is on the inside track, Mars is on the outside. Well, for a little while, as Earth passes Mars, from the perspective of someone sitting in the passenger seat on earth, it’ll look like Mars is sliding backwards. This behavior is really hard to account for if you’re putting earth at the center of the solar system, and even harder to account for if you, a priori, decide that celestial bodies are perfect and thus, can only move in the perfect geometrical shape: the circle. To deal with it, you end up having to create something that looks like the PLANETS are on wheels, MOVING on wheels. They called them epicycles, and man, do they make the solar system look SUPER complex! But even with that, the Greeks were able to make some shockingly accurate predictions about the motion of the stars. And by the 2nd century BCE, a guy named Hipparchus realized that the old Babylonians had made astonishingly precise observations of the stars, because he somehow got his hands on their data. From there, it was off to the races. Greek models and predictions lined up more and more with observable events. All this work sort of culminated in Ptolemy’s Almagest, a giant compendium of geometrical proofs describing the motion of heavenly bodies. Even though it has earth at the center and the odd wheels-on-wheels epicycles, it’s so accurate in what it predicts that it took almost 1500 years for people to find a better way to do it. In fact, it’s almost impossible to be able to tell that it’s predictions aren’t perfect with observations that can be done with the naked eye. It basically took us inventing telescopes to be able to observe with such exactitude that we could see that Ptolemy’s work didn’t totally line up with observable events. The Almagest became the principal astronomical text for Europe and the Arabic world all the way until the Renaissance. It wouldn’t be until Copernicus that there was a major challenge to it. But everyone looked to the Stars and major advances were happening across the globe. When Alexander rode out of Macedon and stormed through the ancient world he brought with him not only war and destruction, but also learning. The conquest which made his name legend to this day also brought Greek astronomical thought as far East as India, and from there pieces even passed to China. But 700 years later, as Rome fell and the light of learning passed out of Europe, it’s these other parts of the world that kept the torch lit and moved forward our understanding of the stars. In India, the Surya Siddhanta was published, establishing the length of a year at 365.2563627 days, only 1.4 seconds off from where we’d peg it today. Ideas of gravitation and the laws of attraction bounce around India while Arab traders pick up astronomical texts to bring back to the expanding Muslim empires. Al-Khwārizmī, the great Persian scholar who gave us the words ‘algebra’ and ‘algorithm’, translated some of these works and began to calculate astronomical charts for himself, bringing a revolution in the approach to astronomy in the Islamic world. By the tenth century, Islamic scholars had developed the astrolabe and are starting to question some of the assumptions made by Ptolemy. And, meanwhile in China, the armillary sphere has been invented and for centuries, the practice of using water clocks to better measure celestial events has been in place. By the beginning of the second millennium the Chinese had even erected a large clock tower that displayed, in real time, the position of the stars. They’d even calculated magnetic north to aid navigation. But perhaps the greatest Chinese contribution to our quest for the stars came from a wholly different field, because by the 13th century, just as the first primitive lenses were being ground out in Europe, we get the first record of rockets being used in war. Desperate to stop the Mongols, the Song Dynasty developed whatever experimental weaponry they could invent: hand grenades, cannons, and of course rockets, but to no avail. Despite their technology, before the century was out, the Song were crushed. But, as the Mongols swept westward, they brought with them these terrifying weapons of war, first to the Middle East, and then to Europe. And, though primitive, they truly began our path to the stars. But before we can get to the Stars, we first have to understand them. So join us next time, as we cover the strides forward in our understanding during the Renaissance and the Enlightenment. The Lotus: Tenno.
Zoey: Meow! Lotus: I’ve detected intruders in your orbiter. I’ve instructed Ordis to open the airlock. Matt: Airlock!? What wait no, no, no, no, no, NO! Lotus, Lotus! It’s me. Lotus: You are not the operator. Identify yourself. Matt: It’s me, Matt from Extra Credits! Lotus: Ah, yes, Zoey’s pet. Matt: Well, that’s not exactly how I would describe it, but- Lotus: How did you get aboard this orbiter? Matt: You know, it’s a funny story. Zoey and I had just come back from lunch and we found this great tex-mex joint Matt: I got a burrito and Zoey got this tomato and cheese gazpacho. You like cheese, don’t you? Lotus: Enough. We do not have time for this. Aa corpus warship is on the move. Lotus: You must find a squad and engage them in ship-to-ship combat. Matt: Ooooh! Dang! You’re talking about Empyrean aren’t you? Matt: Yes, yes, yes, yes. Yes. Yes. YES! I’ve been SO hyped for this since its announcement. I mean, come on! Four player co-op on my Railjack? Dog fighting against super tough enemies? Working together to stop boarding parties, and even strapping on the ol’ Archwing to fly through fricking space to board other enemy ships? I mean who in their right mind wouldn’t be hype for that? Matt: Oh, by the way, I call dibs on the Archwing part. Lotus: With whom are you calling dibs? We are the only ones here. Matt: You know: the.. audience. Lotus: Then gather this audience and prepare for the fight of your life. Matt: You got it, Lotus! Zoey, quick! Get my Oberon Prime cosplay. Lotus: *scoffs* ♫ Music ♫