We try to think up something that could possibly explain what you observe so it would be possible for you to pretend that it's true so you feel like you know what's going on which is our purpose. You can never think up something that could explain everything you observe but we do everything we can to get as close to that as possible. You try to increase the extent to which your explanations could possibly explain what you observe. You try to decrease the extent of contradiction between what your explanations state you should observe and what you actually observe. You try to think up ways, mathematical tricks, gimmicks, ploys by which contradictions between what your explanations state you should observe and what you actually observe are not in fact contradictions. We do absolutely everything we possibly can to achieve anything whatsoever in terms of this. Let's say you are trying to explain some aspect of the Universe. You think up several basic types of explanations. Each explains some aspects of what you observe and contradicts other aspects of what you observe. You focus your attention on the type of possible explanation that contains the least contradictions. You have to get rid of, or explain away, these contradictions. Let's say you focus on one contradiction, and you try to come up with various ways of accounting for the discrepancy. Let's say you come up several basic types of explanations. Each explains various aspects of what you observe and contradicts other aspects of what you observe. You focus on the most promising. In this multilayered fashion, you are trying to think up something that could enable you to come up with something that could possibly enable you to get rid of that contradiction between what your explanation states you should observe and what you actually observe, in terms of a given aspect of the Universe. You try to think up something that could, just could, just could possibly explain what you observe and doesn't violate anything you observe to an extent great enough and in such a way so that you could at that point get it to be able to, force it, ram it, jam it, rig it up so it would, get it to be able to explain what you observe and not contradict what you observe to an extent great enough so that you could at that point ignore the discrepancies between what your explanation states you should observe and what you actually observe, so that you could pretend, just pretend, that it could possibly explain everything that you observe, so that it would be possible for you to imagine that it's true. We do absolutely everything we possibly can to achieve absolutely anything whatsoever in terms of this. This is what we do. We try to think up mathematical tricks, gimmicks, ploys by which contradictions between what our explanations state you should observe and what you actually observe are not in fact contradictions. That is what physics is. We try to decrease the extent of contradiction between what our explanations state you should observe and what you actually observe. We try to increase the extent to which we have something that we can pretend is true.
When previously unobservable natural phenomena become observable, the extent to which your explanations could possibly explain what you observe decreases, and the extent of contradiction between what the explanation states you should observe and what you actually observe increases. When you try to think up an explanation, you're trying to think up an explanation for what you observe, meaning what you observe at that instant. If previously unobservable natural phenomena become observable, what you observe is different because it includes things it did not before. When you thought up your explanations, you did so with the old thing in mind, meaning what was observable before, and without the new thing, meaning what is observable now. Obviously your explanations would fit something they were not designed for to a lesser extent than they would fit something they were designed for. Thus when previously unobservable natural phenomena become observable, the extent of contradiction between what your explanation states you should observe and what you actually observe increases. When supernova 1987A was sighted, people cursed it. It was an additional constraint. Now their explanations had to not contradict this new thing also.
You might therefore ask, why do people delibrately make previously unobservable natural phenomena observable? First of all, if you openly tried to prevent previously unobservable natural phenomena from becoming observable, or even just openly admitted that you don't want it to become observable, you would be openly admitting that if it were to become observable, it would contradict your explanations. Your purpose is to increase the extent to which you can pretend that your explanations are true, and you would be undercutting that purpose. Second of all, the main reason is because people are so desparate to increase the extent to which their explanations could possibly explain what they observe, they don't think straight. Let's say a small child looks in a cookie jar, and there are no cookies. A few minutes later, they look again. The reason is because they want cookies to be in there so badly. Physicists want to increase the extent to which their explanations could possibly explain what they observe so badly, that out of sheer forlorn desparation, they delibrately cause previously unobservable natural phenomena to become observable out of the false hope that somehow maybe that would decrease the extent of contradiction between what your explanations state you should observe and what you actually observe, as if your explanations might suddenly fit something they were not designed to fit better than something they were designed to fit. If they thought more deeply about it, they wouldn't be so eager to do it. The superconducting supercollider was contrary to the purpose of physics.
We try to think up means by which contradictions between what our explanations state we should observe and what we actually observe are not in fact contradictions. I'll give a few examples. Strong force interactions are supposed to have either CP or T symmetry. Then there were discovered strong force interactions that didn't have either CP or T symmetry. That's easy. Invent a hypothetical particle that's supposedly taking part in the interactions in such a way so that they really do have CP or T symmetry. You should invent the particle in such a way so it would not be detectable by us, otherwise the fact you do not detect it would be a contradiction. The primary motivation for deriving Peccei-Quinn symmetry was so that the axion could be employed for this purpose. Luckily, they managed to arrange for the axion to be undetectable. Our most advanced cosmological models are much easier to work with if space is flat. Curvature of space is determined by how much matter throughout the Universe attracts itself. This is determined by the matter density of the Universe, the matter per unit volume, or the amount of matter in the observable Universe. The problem is that the amount of matter in the Universe is about one tenth of that which would have to exist in order for the Universe to be flat. That's easy. Just claim that the Universe contains ten times the amount of matter that it actually contains and that the other 90% would be undetectable by us except in the sense that flattens the Universe. The problem is this raises the question, what is the other 90%? We are in the process of trying to think up something that we can claim is the dark matter.
Whenever you invent explanations, you try to use as much previously invented stuff as possible. Otherwise nothing is connected to anything else. In developing QCD, it was decided that gluons themselves carry color charge so that quarks could change color. Later this fact was taken advantage of to explain something that didn't cross the minds of people at the time. Electrons are surrounded by virtual electron-positron pairs. The positrons face towards the electrons, and partially shield the electron's charge. As you get closer, the effective charge increases. Quarks are surrounded by virtual quark-antiquark pairs that have the same effect. However, since gluons have color charge, they are also surrounded by gluon-antigluon pairs which more than counteract the previous effect. The color charge of a quark is therefore spread out in space, and the effective color charge decreases with proximity. The effective color charge does not decrease with distance, therefore it would require infinite energy to separate two quarks. That's why you don't see free quarks. When people endowed gluons with color charge, they were not intending to explain that detail of the Universe, but later people were able to take advantage of that. If you do that, it helps maintain the illusion that you're not making this up. You have to take the fullest advantage of what's at your disposal. Whenever you invent an explanation, you should incorperate as much previously existing stuff as possible. Otherwise, nothing is connected to anything else.
I remember reading a paper in Physical Review D within which the writer made a reference to a contradiction between what an explanation states you should observe and what you actually observe, namely that certain types of Lorentz wormholes permit time travel. The way he phrased it was "the most distressing, or intriguing implication, depending on your point of view." He accidently slipped up and admitted what we do and then caught himself. The point of view is whether you're admitting what we do or doing what we do. What we do is make up explanations from our own imagination and then afterwards try to pretend that they might have some connection with something existing outside our skulls. Everyone involved in physics knows this full well since that's all physics is, but part of this is pretending that you don't know this. The whole point is to think up something that could possibly explain what you observe so it would be possible for you to pretend that it's true. If you don't go ahead and pretend that this stuff might have something to do with something true then you defeat the whole purpose of this. Some physicists know this full well but would never openly admit it. Some are caught up in the self-delusion to such an extent that they almost convince themselves and thus don't know what physics is or what they're doing. Most physicists actually know deep down what physics is, what it is that we do, and why we do it. They put it out of their mind and just don't think about it. I can read what they write and openly point out what it is that they're doing, something they would not or could not do. Other physicists sometimes accidently slip what it is that we're really doing.
The purpose of many of the papers in Physical Review D is simply to state what it is that our explanations state we should observe or point out that what our explanations state that we should observe is different that what it is generally believed that the explanations state that we should observe.
Often you might have two possible explanations for some aspect of the Universe, and each could explain an aspect of what you observe and also contradicts some aspect of what you observe. What you should do is try to think of a way which the two explanations could be viewed as limiting cases of some larger all-encompassing explanation that has the advantages of each and none of the disadvantages of either.
Thermodynamics does not explain anything that is not otherwise explained so there is no benefit from its invention. It does not increase the extent to which our explanations could explain what we observe. Thermodynamics does not explain anything that is not otherwise explained.
There are subjects devoted to some very minor aspect of the Universe. We understand completely how objects collide in terms of Newtonian classical mechanics. Being able to predict Brownian motion would not increase our understanding of what's really going on. If you understood superconductivity or superfluidity completely, it would not greatly increase our understanding of the fundamental nature of the Universe. This stuff, where if you were to understand it completely it would not shed much light on what's really going on, is what I call "worthless science".
I hate to trivialize the subject with such a prosaic metaphor but the point needs to be made. Let's say you had a banana in a fruitbowl on your table. You leave and come back. You find that the banana is gone and that there is a banana peel in the trash. It could be that a member of your family ate it. It could also be that a strange man and a gorilla entered your house, the gorilla ate the banana, the man threw the peel away, and they both left. The story about the gorilla does not contradict anything that you observe. Is it therefore true? If you can think up something that could possibly explain what you observe and doesn't contradict anything that you observe, is it true for that reason? Does that make it true? The gorilla story did not contradict anything that you observed. However, we have never possessed a view of the Universe that did not contradict what we observed. Therefore, wouldn't you be less likely to believe it? If there is an explanation that contradicts what you observe, it is not possible to pretend that it is true. If something doesn't contradict what you observe then you can pretend that it is true. Therefore we want to have a situation like that, where we can pretend that our view of the Universe is true, but we can never have that. In the late 19th Century, the photoelectric effect, Compton shift, blackbody radiation, and the fact that the speed of light was always measured to be the same, were the only contradictions. That's the fewest contradictions we've ever had. When these things were explained, the contradictions increased. You always have contradictions. You can never erase them completely, so you can never have something that you can pretend is true.
Can you arrive at the truth by this method? Of course not. In the 19th Century, in order to explain the compressibility of gases, people theorized atoms. Atoms exist. That's true. However, in the 19th Century, people imagined atoms as small hard indivisible balls, like marbles. That's untrue. Therefore, the view of the Universe that they possessed was untrue. There exists some reason why there is an apparent pattern in the observed properties of hadrons. If you refer that reason, whatever it is, by the word "quarks", then quarks exist. However, in the future people will think of quarks completely differently than we do. They would say that our view of the Universe was untrue. Does our view of the Universe become more similar to reality as time goes on? The extent to which the view of the Universe that existed in 100 B.C. is more similar to reality than the view of the Universe that existed in 300 B.C. is negligible. Perhaps in the deep future people would say that the extent to which the view of the Universe that existed in the year 2000 was more similar to reality than the view of the Universe that existed in 300 B.C. is also negligible. If you dismiss that as rediculous what you're doing is claiming that our view of the Universe is "close" to reality. Throughout human history people have claimed that their view of the Universe was "close" to reality. Why would we have more right to say that than people alive in 300 B.C.? You have to answer that. A scientist in 300 B.C. claims that his view of the Universe is close to reality. What would you say to him to refute that? Whatever you say could be said about yourself. Any future physicist would say something similar to us. If you thought about what I'm saying you would know full well that the purpose of physics has absolutely nothing to do with "arriving at truth" or anything like that.
We try to think up something that could possibly explain what you observe, so that it would be possible to pretend that it's true, so you would feel like you know what's going on, which is our purpose. We can never have something that could possibly explain everything that we observe but we try to get as close to that as possible. We try to increase the extent to which our explanations could possibly explain what we observe. We try to descrease the extent of contradiction between what our explanations state you should observe and what you actually observe. You try to think up ways, mathematical tricks, gimmicks, ploys by which contradictions between what our explanations state you should observe and what you actually observe are not in fact contradictions. We are trying to gain the ability to be self-delusional. We do absolutely everything that could possibly be done in terms of this. This is are sole purpose. This is the only thing we have ever done.
As a final note, I wish to point out that it may be physically impossible for there to exist an explanation that could possibly explain everything that you observe. The earliest time that it's possible for us to talk about is 5.39 x 10-44 seconds after the origin of the Universe. The reason the speed of light has the value it does instead of some other value has to do with the nature of the Universe between t = 0 and t = 10-44 s. The Universe was the way it was at t = 10-44 s because of what happened between t = 0 and t = 10-44 s. In the future we may be able to talk about that interval, yet there will still be an earliest point in time that we are capable of talking about after t = 0. Why the Universe is the way it is at the earliest time we can talk about has to do with what happened between t = 0 and that earliest time we can talk about. As time goes on that interval will get smaller and smaller but we'll never close the gap. The reason is because at t = 0 there was just mathematical singularity. If you talk about going from t = 0 to t = 0 + an infintesimal unit of time, you're talking about going from singularity to something other than singularity. Why would that other thing be what it is as opposed to something else? We can't imagine an answer to that question because what it is would have to be determined by something. That something has to be between t = 0 and the time you're talking about. There will always exist an interval between t = 0 and the earlist time you can talk about. Your explanations can not encompass that interval. Therefore it's impossible for there to exist an explanation that could possibly explain absolutely everything that you observe.