Entropy, entropy, entropy, entropy, entropy. As a physicist, this word kinda pisses me off because I rarely ever need to talk to non-physicists about it, but when I do, everyone is in a dunning kruger sort of state about it.
Don't worry, though. This isn't going to be an insanely complex article for the layman, at least I hope. Just forget all of the buzzword bullcrap you know about "Oh, dude, it's C H A O S in energy!!!111!!1", and just focus on the basics of energy instead, even though I'm an amateur Physics student who only just completed his Freshman year in college.
Energy doesn't actually exist. Like, at all.
It's a facade. A hoax. A lie. A flat earth. Forget it for a moment. It's all hogwash. One of the biggest ones, too. Highly trained scientists and engineers all over the world have been led to believe in and work with something that doesn't really exist. It's a conspiracy, a global conspiracy, nay, an inter-galactic, time-eluding dirty-backalley-handjob conspiracy that will brainwash your children and send them to the gulag if they attempt to speak out.
Right now, you're hitting hidden knowledge, fundamental truths, divine enlightenment. CIA agents are already tracking your location to come and kill you so that you don't speak out. There's men in black already on their way, less than a mile from your house. That's a shame. It's too bad I'm not a big youtuber or tech writer. If I were, this article would have been prefaced by an ad for a VPN, such as that N one that every youtuber and their moms are paid to promote, and then maybe the CIA wouldn't have caught you red handed. Oh well, maybe another day.
I know, I know. I was going to write a heading like "Oh no, what do I do about this global conspiracy? Why would it spread? What even is it?", but I could smell you through the text editor I'm using. Your stink of apathy betrays you, and if you keep using that iine of thinking instead of stroking your curiousity in the government-approved ways like a good little lemming being churned through the machine, you'll never get anywhere in your life, young man. Or lady. I don't judge. Except I'm clearly judging you for your attitude and behavior right now, so maybe I judge?
But, I digress. Energy. It doesn't exist, it's all in our heads. This is because it's merely a tool we utilize to understand and explain and predict natural phenomena and behavior.
So, one of our two main tools for mechanical physics to describe how things happen and behave is kinematics. We understand how force on an object creates acceleration, which in turn alters velocity (more realistically, momentum), which in turn alters position. If we want to know how fast a ball will go after receiving a force for a certain amount of time, we can figure it out. If we want to know how fast a car will go after accelerating over time while facing wind resistance that scales up over time and the like, we can calculate it with functions to express acceleration over time and integrate them down to velocity functions.
Want the position of something after some forces and after some time? You can set up a system of kinematic equations relating the forces to the acceleration to the velocity to the position by integrating with time to go up the chain to position (or deriving to go down the chain away from it). It takes some basic calculus knowledge and understanding, but it's not rocket science (unless you use it to build rockets, of course). At least, for the most part.
Let's say you have a ball at the top of a hill, and it rolls down the hill, picking up speed until it reaches the bottom, at which point it rolls with a fixed speed. Want to know the speed of the ball at the bottom of the hill? Congratulations, your life with kinematics is now less pleasant and more complex. You need to know the gravitational force on the ball, the force the hill applied, the amount of time it took the ball to reach the bottom, which can be calculated based on the acceleration if you use more calculus than usual, all plugged into your velocity equation. And then, if the ball goes up a ramp and you want to see how high it goes, prepare for even more long winded calculations!
So, we needed a new tool less literal and in the moment than kinematics. Kinematics seems great for calculating stuff with time and force involved, but that's not practical for all applications. Sometimes you don't know the amount of time a force is applied, but rather a distance. What do you do then, turn the distance into a time? What about for changing velocities?
Instead of considering the simple momentum of an object, which seemed to change with time, we needed something more versatile, a quantity that could define more than just momentum. What if we considered how, in a scenario, height above the ground can convert into a large momentum, or vice versa? What if we considered how a force and potential thereof of, say, a compressed spring, can be "used up" and "spent" on making a stationary object go fast . . . or, what if we talked about how it can happen the other way around? This thinking is what leads into using energy to describe the behavior of objects, or "systems" as physicists like to refer to them. (I mean, a system can include multiple objects, you can really define a system in a problem as you see fit, as long as you're consistent in your definition).
Of course, the first thing to understand is that all energy is conserved. The universe at large never gains or loses energy, it just converts it into different forms. Lets say you chuck a ball up into the air. It goes up, slows down on the way up, stops, and starts falling. That ball as a system has just as much energy on the way up as it does on the very top; it's just that more of that energy is gravitational potential energy on top than kinetic energy.
When energy is transferred from one system to another, it's called "Work". However, it's just that, a transfer, so a system with only so much energy can only do so much work. Therefore, energy is the maximum ability of a system to do work on other systems. It's a circular definition, sure, but physicists seem to be pretty happy with it.
The equation for work is as follows:
Work = Force * Distance
So, going back to that ball going down the hill, this is a simple case that can be looked at multiple ways. If you define the system as just the ball, the ball starts with no energy. However, the earth does work on it in the form of gravity. This work is energy transferred from the earth into the ball, and is stored in the ball as kinetic energy. It's only done until the ball reaches the bottom of the hill. If we want the speed of the ball at the bottom of the hill, all we need is the gravitational force times the distance it acted upon, or at least the distance perpendicular to the direction of the force. The force of gravity is going straight down, so we need to figure out how far down the ball went. So, your equations would look like this:
Ball initial energy = 0
Ball final energy = initial energy + work done
Work = gravitational force * height of the hill = mass of ball * 9.81 m/s^2 * hill height
ball kinetic energy = work
This gives us the kinetic energy, but we don't know how to get the velocity from it. Here's the equation that relates kinetic energy and velocity:
kinetic energy = (1/2) * mass * velocity^2
So, to get the velocity, we would just plug in the work done for the kinetic energy, and solve for it algebraically. Of course, this assumes an ideal world with no friction. Thankfully, the energy principle can account for friction; it, too, does work on our system, and we can calculate that work if we know the parallel distance it acts along.
Pretty soon.
A form of energy is heat energy. This is actually characterized as another form of kinetic energy with some simple reasoning. All the atoms and sub-atomic particles that make up an object are constantly moving. In the form of a solid, they vibrate violently. In the form of a liquid, they slide around and vibrate plenty. In the form of a gas, they bounce everywhere. The temperature of a molecule is actually a remark of how fast and violently and freely those particles are bouncing about. The hotter, the faster.If you feel hot, it's because your atoms are vibrating faster than usual.
So, hot objects have more of this kind of "kinetic energy" since those sub atomic particles are vibrating with higher velocities. Ergo, they
fuck it, I'll write this article next year.
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