Why Science is "Yeah" Worthy
Simply put, science is the best way to understand the physical world. Actually, its the only way of understanding the physical world. Did trendy Asian-fusion folk remedies cure Polio? Did moon crystals take us to the moon? Does the National Weather Service use astrology to predict natural disasters? No! Science did all those things! Science gave us fire! Science gave us indoor plumbing! Science gave us computers and the internet! Science brings home the bacon and what thanks does it get? Six seconds of praise on Breaking Bad.
Rather than start off with a tedious 10 page explanation of the scientific method like every science textbook I've ever read, I'll just give you the basics: predict shit; test shit; rinse and repeat. Moving on.
Astronomy and Early Science
The most basic principle of science is that our universe is as predictable as the sunrise. It's fitting then, that the first science was astronomy, the one that predicts the sunrise. Like many things, it started with the Greeks and like most things that started with the Greeks, a lot of it was bullshit.
I rest my case.
In the second century CE, Claudius Ptolemy came up with the first model of the solar system. In the Ptolemaic System, the planets and stars all revolve around the Earth in circular orbits. Anyone reading this probably already knows that part, but what you might not have heard is that, in this model, the planets move in smaller circles independent of their orbits. This would explain uneven planetary motion and eclipses. The Ptolemaic System would remain unchallenged until the work of Nicolaus Copernicus was published in 1543. Those capable of math are probably wondering how a theory so wrong could be so prevalent for such a long time. Well, it honestly was the best theory at the time. Think about it, do you feel like you're barreling through space at 67,000 mph right now? Probably not. It explained every event in space people knew about back then, so it isn't any wonder that it was so popular. As for the Copernican System, it moved the Sun to the center of the solar system, but it kept the circular orbits, so it's wrong too. We wouldn't get an accurate model of the solar system until the men known as Tycho Brahe and Johannes Kepler showed up.
Before I get to his essential contributions to science, there are a couple of things you should know about Tycho: one, he was fucking awesome and two, he has nothing to do with dickwolves. Tycho's first big break was his discovery of a new star. This was a big deal because, at the time, it was believed the heavens never changed. The King of Denmark was so impressed by this discovery that he gave Tycho an island, like, a whole island, and the resources to build a big, fuck-off observatory (Tycho's uncle dying to save the King probably didn't hurt). From there, Tycho spent the next twenty-five years getting highly accurate measurements of the positions of stars and planets. Oh, and when he was in university he got into a duel with some nameless jackass over who was the better mathematician; Tycho lost his nose, but I think we all know who lost the argument.
When Tycho died, his assistant, Johannes Kepler, took up where his boss left off. Using Tycho's data, Kepler was able to show once and for all that, no, the Sun does not revolve around the Earth. He also discovered that the planets move in elliptical, not circular, orbits. Thanks to these two, we finally figured out how the planets move. Unfortunately, we still didn't know why the planets move. That question would be left to scientific juggernauts, Galileo Galilei and Isaac Newton.
Motion and Gravity
When Tycho died, his assistant, Johannes Kepler, took up where his boss left off. Using Tycho's data, Kepler was able to show once and for all that, no, the Sun does not revolve around the Earth. He also discovered that the planets move in elliptical, not circular, orbits. Thanks to these two, we finally figured out how the planets move. Unfortunately, we still didn't know why the planets move. That question would be left to scientific juggernauts, Galileo Galilei and Isaac Newton.
Motion and Gravity
Galileo is probably most famous for his heresy trial; that or Bohemian Rhapsody. The trial is thought of by many as a champion of truth being punished for refusing to submit to Catholic Voodoo. The far less romantic truth is that Galileo was kind of an asshole and he pissed off the wrong people. Heliocentrism wasn't illegal, making fun of the Pope during the Inquisition was illegal. Still, none of that changes the fact that Galileo was a brilliant man who made invaluable contributions to science. The most important of these was the invention of the experiment. See, Greek philosophers believed that human observation was inherently flawed, so they believed the only way to learn about the world was through pure reason. One problem with this method is that humans aren't reasonable. If we were, it wouldn't have taken us thousands of years to figure out that, rather than sitting around arguing about whether or not a heavier object falls faster than a lighter object, we can just roll two balls of different weight down a slope and see which takes longer to hit the bottom. This is precisely what Galileo did, jump starting modern science in the process. Through this experiment he discovered that distance is equal to speed times time (a.k.a. the very first formula you forgot in high school algebra).
Galileo is often given credit for the invention of the telescope, but earliest known telescope was actually made by Hans Lipperhey, a craftsman from the Netherlands. It's an easy mistake to make as Galileo was the first person to record observations with a telescope.
Isaac Newton built on earlier ideas of motion with his famous laws. First, a moving object will continue moving in a straight line unless force is applied; likewise, an object at rest will stay at rest. This seems obvious, but it was once believed that objects would move in circles unless acted on by a force. The Greeks and, by extension, medieval scholars really liked circles. Second, the more mass an object has, the harder it is to move. This is why it is easier to lift a brick than a house. The second law also states that an object will accelerate faster as greater force is applied; a ball moves faster if you throw it harder. Third, for every action there is an equal and opposite reaction. This is why you risk breaking your hand if you punch a slab of concrete really hard. Think about it this way, when you walk you aren't exerting a force on yourself, you're pushing against the ground. The Earth is too big to be affected by the force, but you aren't, so you move instead. In a sense, the Earth pushes back against you.
It didn't take Newton long to realize the implications of his laws. While looking at the Moon in an apple orchard, Newton had the mother of all "ah-ha" moments; if circular isn't the default direction of motion then why the fuck is the Moon moving in a circle? The only sensible answer is that a force is acting on the Moon to keep it in orbit. He then saw an apple fall and figured "huh, maybe it's the same thing."
And that's how we got the law of universal gravitation. This was a huge deal. Sure, even ancient people knew that something kept us tethered to our planet, but before Newton, no one considered that the same force was active all throughout the universe. People just kind of assumed that Earth physics and space physics were two completely different things; this was the law that finally demonstrated they are, in truth, the exact same physics!
Basically, the law of universal gravitation states there is an attractive force between any two objects in the universe. Yes, even those two. The bigger these objects, the stronger the gravitational pull is between them; furthermore, gravity becomes weaker as the distance between the two objects increases.
See? Gravity is actually pretty simple; well, at least until relativity (more on that later). Physics kinda got weird after Einstein showed up.
Sources:
The Sciences: An Integrated Approach
www.nasa.gov
galileo.rice.edu
Galileo is often given credit for the invention of the telescope, but earliest known telescope was actually made by Hans Lipperhey, a craftsman from the Netherlands. It's an easy mistake to make as Galileo was the first person to record observations with a telescope.
Isaac Newton built on earlier ideas of motion with his famous laws. First, a moving object will continue moving in a straight line unless force is applied; likewise, an object at rest will stay at rest. This seems obvious, but it was once believed that objects would move in circles unless acted on by a force. The Greeks and, by extension, medieval scholars really liked circles. Second, the more mass an object has, the harder it is to move. This is why it is easier to lift a brick than a house. The second law also states that an object will accelerate faster as greater force is applied; a ball moves faster if you throw it harder. Third, for every action there is an equal and opposite reaction. This is why you risk breaking your hand if you punch a slab of concrete really hard. Think about it this way, when you walk you aren't exerting a force on yourself, you're pushing against the ground. The Earth is too big to be affected by the force, but you aren't, so you move instead. In a sense, the Earth pushes back against you.
It didn't take Newton long to realize the implications of his laws. While looking at the Moon in an apple orchard, Newton had the mother of all "ah-ha" moments; if circular isn't the default direction of motion then why the fuck is the Moon moving in a circle? The only sensible answer is that a force is acting on the Moon to keep it in orbit. He then saw an apple fall and figured "huh, maybe it's the same thing."
And that's how we got the law of universal gravitation. This was a huge deal. Sure, even ancient people knew that something kept us tethered to our planet, but before Newton, no one considered that the same force was active all throughout the universe. People just kind of assumed that Earth physics and space physics were two completely different things; this was the law that finally demonstrated they are, in truth, the exact same physics!
See? Gravity is actually pretty simple; well, at least until relativity (more on that later). Physics kinda got weird after Einstein showed up.
Sources:
The Sciences: An Integrated Approach
www.nasa.gov
galileo.rice.edu
