What is time? What is action? Why are they here together?

Time. This word is familiar to everyone. And not just a word. Everyone has an intuitive idea of ​​time.. On the other hand, so many myths are associated with this concept, so many completely different views. Especially when people are trying to make sense of ideas., appeared in science in the process of creating theories of relativity at the beginning of the 20th century. The everyday concept of time, by and large, very accurate, but at the same time it is contradictory. Because it is multifaceted and not formalized to the end. And that's okay for our common languages.. Of all, apart from scientific. When trying to formalize the concept of time, at the beginning, Newton, certain over-generalizations have been made, which later turned into dogma and through school returned in this form to everyday consciousness. Physics at the frontier 19-20 centuries came to the realization of the excessiveness of these generalizations. However, Newton's theory remains the basis of the physical picture of the world., produced at school. And both theories of relativity remain poorly understood even by those people, who use them and develop them. I am driving speech about the concept of containing space and universal time, as an arena for all things. Maximum, what in most cases one gets in this direction, this is the idea, that matter affects the properties of space-time. it, of course right, but too little.

What is time at the simplest level? Probably, I will not reveal any secrets, if I say, what time for all of us is synonymous with a sequence of events. Statement “time runs” means, that some events are taking place. Moreover, not somewhere out there, and with us, in our existence. It doesn't matter here, whether we are talking about the existence of a subject, animate or not. The keywords are the words “Existence“, “sequence of events“, “time flow“. And all these are practically names for the same. But if I say, that this is the quintessence of the concept of time, and there is nothing else in it, a lot of people will start arguing with me… but, in a completely peeled form, I will give just such a formal definition of time. Time is a sequence of interrelated events. AND different such sequences give different times. Time – local concept. Even if it's some common time, let's say for planet earth. And one more thing I will say. Extremely simple. And at the same time extremely important. Everything, what we really know and can know about the world – it is a set of events and connections between them. Any dimension, no matter how difficult it is, can always be reduced ultimately to a statement of the facts of events, their connections, and nothing more. Not all events line up. More precisely, such sequences of events, which can be called the passage of time, many different. Sometimes overlapping, more often not intersecting. Their presence allows us to introduce an idea of space. But now we will only talk about time and its properties..

First, the obvious question would be – if time is only a sequence of events, then it comes out discreetly? And that, and no. And that's why. Events, which we most often deal with are complex. In the sense, which consist of many other events. They can be divided. Events overlap with each other and at the level of the classical description of the world, existence as ours, so all objects looks quite continuous. And therefore we depict the existence of something as an unbroken chain of dots., and the merging chain of points, continuous line. Assuming in this event every moment of continuous existence. This point of view is deeply rooted in our minds, how common, and scientific. She means, what every moment of existence of all things, every point of the universe is an event. The space-time of any classical theory of the world is nothing else., as an event space. This was most clearly manifested in the last such successful theory, General Theory of Relativity. If in Newton's the picture of the world, continuous space-time was an arena for physical processes and the identification of its points with events remained for the most part implicit, then in general relativity this is already a completely integral part of the theory. No matter how sophisticated math is applied, in the end, all, what the theory says – these are statements about the properties of the intervals between events. And since events are all points of space-time without exception, then these are statements about the properties of the intervals between all points of space-time.

But here's the trouble. If you think better about the deepest meaning of this word, “event”, it turns out, that for us it's still not every moment. Moments of being, existence, in which nothing happens, we are not really inclined to consider events. Even at the household level. And when formalizing this concept into a scientific system of views, there is no choice at all. Only that point in space-time can be considered an event., about which we have information. This problem has risen to its full height, when physics, in its quest to know nature, got to atoms. It was resolved by the creation of quantum mechanics. The new theory turned out to be very successful in describing the range of phenomena, in which events no longer merge into continuous sequences. Here are just the reasons, on which this theory rests have not been worked out to the end. Which causes from time to time new attempts to deal with them.. There is another side effect of the lack of a consistent interpretation of quantum theory., its actual connections with the classical theory. I'm talking about never-ending attempts to build a theory quantum gravity. Attempts to combine general relativity and quantum theory. Unsuccessful and fruitless efforts, for a simple reason. The thing is, what General relativity is essentially a classical approximation. The concept of metric integrates our broadest understanding of distributed, classical frame of reference. This concept remains just as necessary in the quantum description. Which is what was understood N.Borom as complementarity principle. Frame of reference (and hence the metric) it's just pointless to quantize. But the concept of the classical frame of reference also includes time. What happens, time also cannot be quantized? But what about, what's the chain of events, realizing the passage of time, is always discrete for us?

This is where you need to remember about such a concept of physics, as an action. If time is familiar to everyone, that action, even for physicists, is still a rather mystical concept.. And in what sense. IN physics action appeared as a secondary quantity, calculated in terms of time and energy-momentum (or mass, if we restrict ourselves only to rest systems). At the same time, it was discovered, that this quantity, for unknown reasons, for all physical phenomena always takes the minimum of all possible values. Actually, all ratios, colloquially called the laws of nature, can be obtained in classical physics from this principle. Minimum principle (more precisely, stationarity) actions. This already says, what action – something much more important, than the result of some calculations. Even more clearly, the importance of action for physics was revealed by the emergence of quantum mechanics. After all, something is not quantized in this theory., namely action! The need for a new, different from the classical description of the world arose precisely from the understanding, that the action is not continuous, that it is discrete. And how does this relate to the discreteness of time, viewed as a sequence of events? It is enough to identify the discrete time, understood as a sequence of events, with the physical concept of action, how easy everything will fall into place. In this case, time may well remain a classical continuous quantity in the sense, that the intervals between events can be thought of as continuous. Only the existence in them we do not consider events. So this is not a problem even for ordinary language.. Events – it's something special about existence. And then discrete time, which only takes into account events, is part of continuous time, immersed in it, may well have another name. Act. Moreover events, which the action considers, are that skeleton, which must be present in our description of the existence of any object or part of the world. After all, these are events known to us, they were, we know about it. There are just so many, how much was – no more and no less. The time intervals between events can be different. There were no events. We don't know anything about these gaps. Infinitely many continuous lines can be drawn through a given number of points. If only the marked points themselves on each such line remain in the same order and in the same quantity. The lines can be varied, keeping stationary the number of given points on them. So events are those points of the world, which, and only they, must be included in any description of this part of the world. The description of the world can be varied, keeping the action value as a stationary description element. Here this is the principle of stationarity of action. And what is mystical left in him?

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