Don't give me an equation, tell me exactly what energy is, because every book seems to use it without defining it, or the definition makes no sense like in the picture
>>17056084The conserved quantity that corresponds to time-translation symmetry.
>>17056084>I carried a bowling ball up a hill, so I stored energy in it.
>>17056087>The conserved quantityquantity of what?>that corresponds to time-translation symmetryenergy is time then?
>>17056084Energy is ability to do work.Ability means exactly what you think it means.Work is changing from one state to another state.
>>17056147>Ability means exactly what you think it meansan abstraction with no basis in reality but instead a word used to not think too deeply about what actually allows the result of it to happen?
>>17056087/thread>>17056084Work is pushing an object of some mass (which is loosely related to weight) for some distance. If you push a heavier object, the work is greater. If you push the object for a greater distance, the work is greater.Energy is the ability to do work. Which is to say that it's basically like an imaginary scoreboard, changes to it are measured by work done on other objects or from other objects.
>>17056154define "allows"
>>17056142>quantity of what?
>>17056154Pretty much. It is a broad generalization which describes a set of all potential causes without wasting time on the minutia of specific case dependent causes. Energy itself is a generalization which describes many things. It's just useful to reify the broad category as a single thing since it's easier than being autistically explicit about potential and kinetic "energy" being fundamentally different things which happen to have a perfectly proportional conversion ratio, for example.
>>17056154>an abstraction with no basis in realityWhy do you hate numbers so much? Did you get filtered by having to count beyond your grand total of 6 fingers?
The fuck is reality anyway my negro
>>17056167you can say dark pony energy is a quantity toodoesn't mean it actually exists or has any basis in reality>>17056155>Work is pushing an object of some masswhat is doing the pushing? is work involved in making that something start the push? so work causes work?>If you push a heavier object, the work is greateris work the act of pushing or is pushing another word for effort (therefore not the pushing itself), and what you're doing is naming a measurement (you do do the same with movement and time, the longer the distance the higher the time to cross it, but this doesn't explain what time is or what's causing the movement)but not actually explaining what is it that is behind what's being measured?> Energy is the ability to do workwhat is ability? a hand pushing something doesn't have "energy", it has mass (tissues, ligaments, bones, etc.) moving mass to create movement on another mass. there is no need to say muscles have any "ability" to move something and call that energy, because all you're left with is a metaphysical description of something that doesn't need a metaphysical description >>17056167yes, quantity of what?>>17056168>a set of all potential causeswhat is a set?and how is 1 unit of energy smaller than 2 units of energy if both include "all potential causes"?>without wasting time on the minutia of specific case dependent causes.how can there be any case dependent causes if energy is the potential for anything?>Energy itself is a generalization which describes many things. that wouldn't be a problem if only physicists didn't treat the word as an actual thing like an orangeit's like sewing the emperor's new clothes and doing mathematics based on the properties of it
>>17056168>It's just useful to reify the broad category as a single thing since it's easier than being autistically explicit about potential and kinetic "energy" being fundamentally different things what are "potential energy" and "kinetic energy"? dividing energy into more words doesn't make it less real>which happen to have a perfectly proportional conversion ratio, for example.mathematically accurate models about nothing do not change its status of nothing
>>17056171>Why do you hate numbers so much? Did you get filtered by having to count beyond your grand total of 6 fingers?when you use a number you can point at something and show what it represents now take "energy" and point at what it represents. go on. an actual physical thing, not your imagination
>>17056172people seem to agree that energy = capacity to do workok, let's ignore the word work for a second where is "capacity" located? what is it made of? how big is it? what's its shape?
>>17056185>or is pushing another word for effortwork i meant
>>17056185>yes, quantity of what?>>17056189>when you use a number you can point at something and show what it represents
>>17056197let me make it more simple for you chumpgo to the bank to borrow money and say you'll pay your interest in "energy"when they ask you what is "energy", say it's the capacity to do work when they ask does that mean you'll work to pay the interest, say not at all, it's just the potential for work to happenafter you're asked to provide evidence that such potential substance physically exist, make sure you're not just giving other physical things like atoms
>>17056199How about next time you use the number two, you point at something to show what it represents and then think long and hard if you did it correctly, you absolute mong. Because protip: you didn't.
>>17056185>that wouldn't be a problem if only physicists didn't treat the word as an actual thing like an orangeThey don't. Physicists have a full understanding that "energy" is a man-made abstraction.>how is 1 unit of energy smaller than 2 units of energy if both include "all potential causes"?A ball sits twice as high as another ball. That ball can cause twice as many things to happen if released.>>17056186>what are "potential energy" and "kinetic energy"?Potential energy is the work a thing can do.Kinetic energy is the work it is doing.>mathematically accurate models about nothing do not change its status of nothingStuff doing things to other stuff is real though. "Energy" is just a made up concept used to describe it.Getting hung up on terminology is low IQ behavior.
>>17056204>How about next time you use the number two, you point at something to show what it representsyou go to the bankclerk says your debt is twoyou ask two whathe apologizes, says it's two dollarsyou give him the two dollarsyou come back to the bankclerk says you own energyyou ask him energy whathe says your potential as a human being you're killed on the spot
>>17056208Notice how your mental illness caused you to write a completely incongruent reply.
>>17056206>Physicists have a full understanding that "energy" is a man-made abstractionhttps://en.wikipedia.org/wiki/Energy>the quantitative property that is transferred to a body or to a physical system, recognizable in the capacity to do work and in the form of heat and lightthey not only not realise it's a fictional manmande thing, they think you can actually transfer it, like money in a bank account, and that heat (the movement of atoms) and light, in any way shape or form, prove it exists!>A ball sits twice as high as another ball. That ball can cause twice as many things to happen if releasedit can cause more things not because of something without any location, size, shape or anything physical as "energy", but because the ball, by being higher, is being pushed by other balls at a higher rate ( https://en.wikipedia.org/wiki/Mechanical_explanations_of_gravitation ) since by being more distant to the group, it's closer to the incoming balls from above see? no need to invoke an abstract notion with no substance to it>Potential energy is the work a thing can do.>Kinetic energy is the work it is doingyou don't realise the contradiction in this?potential energy is just kinetic energy before it happens, but then kinetic energy is just one of the many possible states of potential energy>Stuff doing things to other stuff is real though.correct. a ball hitting another is a real thing. you can point at it, you can model it with some other physical thing too>"Energy" is just a made up concept used to describe it."doing stuff" isn't described by energy. movement describes it. >Getting hung up on terminology is low IQ behavior.not getting hung up on terminology is exactly how you end up with "dark energy" and other signs of permanent stagnation in a dying field
>>17056087Whole in 1. Well done.
>>17056224>Wikipedia gave me this brief simplification of the concept and I am going to use that to assert physicists actually believe my uncharitable reading of that simplification Again, low IQ.>they think you can actually transfer itEver play pool?>because the ball, by being higher, is being pushed by other balls at a higher rateAnd energy is the magnitude of all those forces being applied. It's an abstract quantity used to put many things under one umbrella.>potential energy is just kinetic energy before it happens, but then kinetic energy is just one of the many possible states of potential energyThat's not a contradiction.>not getting hung up on terminology is exactly how you end up withKek. Wordbrain.>dark energyJust the sum of whatever forces are causing the accelerating expansion of the universe. You got filtered by the word "dark."
>>17056185>what is doing the pushing?A force. Inb4 "What is a force" you should go study biomechanics (actin proteins etc) if you want to learn how humans do it.>is work the act of pushingWork is a number that quantifies how much pushing is being done.>it has mass moving mass to create movementThis is force. Any work done by this force decreases energy, which again is an imaginary scoreboard, more or less.Also all of these concepts are real in the Platonic world and you're a low IQ wordcel.
What the fuck do you want some random 4channer to say that you couldn't find from an article? You can only zoom in so much, eventually we cannot answer why
>>17056231>Wikipedia gave me this brief simplification of the concepthttps://understand-energy.stanford.edu/introduction-energy/energy-basics>Energy is a conserved quantity that can be accumulated and is transferred as heat, work, and in matter.again, an actual thing question is, has any scientist managed to catch that "quantity" between its transfering states? because if they haven't, it simply doesn't exist
>>17056236>, an actual thingWhere does that page say that?And my critique wasn't about Wikipedia itself. It's about the simplified explanation. Exactly the sort you'd find on a Stanford.edu page titled "energy basics" which you still managed to misread by filling in blanks with your own stupid little brain.
>>17056185>what is doing the pushing?Whatever is pushing it
>itt
>>17056275Both top and bottom are correct.
>>17056084Energy is an unknown whose existence we assume because it allows us to try to understand stuff. If you want to understand what it is beyond just a name, you have to look into the only chunk of matter in the universe that you can observe “from the inside,” i.e. your own body and mind
>>17056084>because every book seems to use it without defining itThis is false. Basically every book will define it as something along the lines of >[math] H(x,p) := \tfrac{p^2}{2m} + U(x) [/math]or >[math] E(x,v) := \tfrac{mv^2}{2} + U(x) [/math]>Don't give me an equationYou don't seem to understand what physics is. Physics isn't some Holy Bible that describes how the universe was created, why the devil exists, or why bad things happen to good people. >[math] \textit{Physics is a means to predict outcomes given initial conditions using formal (as much as it can) mathematical models} [/math]Does "the field" exist?? Do irl particles take "all possible paths"?? Does "the wavefunction collapse" irl?? <-- Physics isn't meant to answer these questions! A physicist develops a mathematical model whose objects and their properties can be represented in some way, and using said model, evolves these quantities over time - if the model matches real-world experimental data well, then the model has strong predictive power. There is NO current model that predicts EVERYTHING accurately! All models will fall and be replaced by a better one. To simply [math] \textit{assume} [/math] energy, momentum, or similar concocted MATHematical object is something irl "real" or "tangible" is just extrapolating. Maybe you're right, maybe you're wrong. But treating it like some dogmatic bible ghost is just bad interpretation.In the following posts I will respond to your questions(1/4)
>>17056331>what is ability; work'ability' is odd, but I assume it's because you often see something akin to >...the capacity/ability to do work.Meh. Supposed a particle is in a potential energy field that is constant but above zero. Is the particle gonna move? NO! Only a gradient in this field produces a force! So what do you mean that energy is 'something, something, ability to do work' when no work is being done at all here? Assuming one understands energy and that it can be exchanged, >Work is essentially the net energy exchange associated with changes in an object's velocity. Like, you could lose energy to heat up something, but no work was being done cause the bulk object's velocity didn't change. You really gotta use ability in a sentence cause it just seems vague rn>what is energyEnergy is a particular 'property' := function: Math Object -> Real Number of some predefined MATH object (a particle, group of particles, a field, etc). To model an irl massive particle, we simply associate it to a "math" particle and the above definition of energy in normal cases. In some abnormal case or a massless particle, the energy/hamiltonian function will be different. [math] \textit{Energy is some quantity associated with an object that is vital to predicting the evolution of said object's state accurately} [/math]Momentum is too, what's the point? And the position function x(t) is the most important since it describes the state evolution directly - well no fucking shit, but we need a means to find x(t) or any other state function given INITIAL (or BOUNDARY) conditions. Key words there - this should sound awfully like solving a calculus differential equation. Things like Energy and Momentum are just quantities (functions) associated with means to determining state evolution or x(t). We could end it here, but let's keep going(2/4)
>>17056332An important property of these quantities is that (or when) they're conserved. In math and physics, many complex problems are solved or categorized by considering fixed points, conserved values, or invariant values; when you can find something that isn't changing, problems can become much more simple. You've probably read stuff like how Energy is conserved over time. But how do you know? (Asking 'how' is akin to asking 'why'). Experiment can show it sometimes. And furthermore, the math model forces it, and this model the predicts state evolution is accurate for many experiments. Predicting experimental data well is how we trust the model. Ok, >but why does the math model enforce it? THIS, we can answer. It's always the same>1. Define functions>2. Define equation that evolve the state (axioms)>3. Combine both and do math>4. ConclusionFor Hamiltonian mechanics, the Hamiltonian function (energy) H(x,p,t) is DEFINED. Then, two 1st order differential equations are DEFINED (or axiomized as TRUE). In combining them, we get a crazy result: [math] \tfrac{dH}{dt} = \tfrac{\partial H}{\partial t} + \underbrace{ \{H, H\} }_{=0} [/math] along the solutions to the coupled diff eq, which is literally the first postFor Lagrangian mechanics, the Lagrangian function L(x,v,t) is DEFINED. Then, one 2nd order diff eq. is DEFINED (or axiomized as TRUE). In combining them, we get a crazy result: [math] \tfrac{\partial L}{\partial t} = 0 \ \Rightarrow \ \tfrac{\partial L}{\partial t} = - \tfrac{dH}{dt} = 0 [/math] along the solutions to the diff eq, again, mentioned in the firs postSimilar can be done for Hamilton-Jacobi mechanics w/ action S(q,t), higher dim stuff, etc etc. Btw, momentum as an equation pops out from the above. Too much to talk about Energy-momentum-mass, but to understand them, u'd need to start with some previously defined stuff(3/4)
>>17056333You start out with predefined stuff quantities, predefined eqs. whose E.O.M solutions accurately match those in IRL experiments, and using some math can determine when you get conserved quantities. And in many cases, the fact that something is conserved or symmetric can help you find the E.O.M faster w/o doing any diff or vector calculus, as in many simple school problems. 'Work' is pretty direct from it's definition>but why [math] textit{these} [/math] definitions in particularPeople here point out that "something, something, time symmetry", but Noether's theorem requires starting at one of these equations and definitions. So again, you end up questioning why these in particular. The answer is the same: who tf knows? PHYSICS ISN'T MEANT TO ANSWER THIS! It just gives a good predictive model, that's it! You may question 'why' these quantities, but what about position x(t)? There seems to be ample evidence pointing to the fact that IRL particles DO NOT have a well defined position (and momentum concurrently, at least), unless you believe that there exists a better model that does allow for them to be well defined. But assuming they aren't, why question Energy when you aren't questioning position or momentum??? What if Energy is a 'real' property of objects and that position and momentum/velocity are the 'less real' ones? Your intuition on 'knowing' the object's state in terms of (x,p) simply isn't correct! The universe doesn't gaf - an object exists regardless of how you categorize or describe it. Maybe only fields and their energies 'are real'! Hell, wtf does it mean to even be "real"?? Nobody is saying not to question these objects, their properties, or their existence, but if anything that you should be flexible about the MATH models you're using and to question MATH model derivation and pursue improvement. The more you understand the nuances, the more you understand what "it" is(4/4)
