SRT, TOE - under these abbreviations lies the term "theory of relativity", familiar to almost everyone. Everything can be explained in simple language, even the statement of a genius, so do not despair if you do not remember the school physics course, because in fact everything is much simpler than it seems.
The Birth of Theory
So, let's start the course "The Theory of Relativity for Dummies". Albert Einstein published his work in 1905 and it caused a stir among scientists. This theory almost completely covered many gaps and inconsistencies in the physics of the last century, but, in addition, it turned the idea of space and time upside down. It was difficult for contemporaries to believe in many of Einstein's statements, but experiments and studies only confirmed the words of the great scientist.
Einstein's Theory of Relativity explained in simple terms what people had struggled with for centuries. It can be called the basis of all modern physics. However, before we continue talking about the theory of relativity, we shouldclarify the issue of terms. Surely many, reading popular science articles, have come across two abbreviations: SRT and GRT. In fact, they mean somewhat different concepts. The first is the special theory of relativity, and the second stands for "general relativity".
Simply complex
SRT is an older theory that later became part of GR. It can only consider physical processes for objects moving at a uniform speed. The general theory can describe what happens to accelerating objects, and also explain why graviton particles and gravity exist.
If you need to describe the movement and the laws of mechanics, as well as the relationship of space and time when approaching the speed of light - this can be done by the special theory of relativity. In simple words, it can be explained as follows: for example, friends from the future gave you a spaceship that can fly at high speed. On the nose of the spacecraft is a cannon capable of shooting everything in front with photons.
When a shot is fired, relative to the ship, these particles fly at the speed of light, but, logically, a stationary observer should see the sum of two speeds (the photons themselves and the ship). But nothing like that. The observer will see photons moving at 300,000 m/s, as if the speed of the ship was zero.
The fact is that no matter how fast an object moves, the speed of light for it is a constant value.
Thisthe statement is the basis of amazing logical conclusions like slowing down and time distortion, depending on the mass and speed of the object. Many science fiction films and series are based on this.
General Relativity
A more voluminous general relativity can be explained in simple terms. To begin with, we should take into account the fact that our space is four-dimensional. Time and space are united in such a "subject" as "space-time continuum". There are four coordinate axes in our space: x, y, z and t.
But people cannot directly perceive four dimensions, just like a hypothetical flat person living in a two-dimensional world is unable to look up. In fact, our world is only a projection of four-dimensional space into three-dimensional space.
An interesting fact is that, according to the general theory of relativity, bodies do not change when they move. The objects of the four-dimensional world are in fact always unchanged, and only their projections change when moving, which we perceive as a distortion of time, reduction or increase in size, and so on.
Elevator experiment
The theory of relativity can be explained in simple terms with the help of a small thought experiment. Imagine that you are in an elevator. The cabin began to move, and you were in a state of weightlessness. What happened? There can be two reasons: either the elevator is inspace, or is in free fall under the influence of the planet's gravity. The most interesting thing is that it is impossible to find out the cause of weightlessness if there is no way to look out of the elevator cabin, that is, both processes look the same.
Perhaps, after conducting a similar thought experiment, Albert Einstein came to the conclusion that if these two situations are indistinguishable from each other, then in fact the body under the influence of gravity does not accelerate, it is a uniform movement that is curved under the influence of a massive body (in this case planets). Thus, accelerated motion is only a projection of uniform motion into three-dimensional space.
Illustrative example
Another good example on "Relativity for Dummies". It is not entirely correct, but it is very simple and clear. If any object is placed on a stretched fabric, it forms a "deflection", a "funnel" under it. All smaller bodies will be forced to distort their trajectory according to the new curvature of space, and if the body has little energy, it may not overcome this funnel at all. However, from the point of view of the moving object itself, the trajectory remains straight, they will not feel the curvature of space.
Gravity "downgraded"
With the advent of the general theory of relativity, gravity has ceased to be a force and is now content with the position of a simple consequence of the curvature of time and space. General relativity may seem fantastic, but it is workingversion and confirmed by experiments.
Many seemingly incredible things in our world can be explained by the theory of relativity. In simple terms, such things are called consequences of general relativity. For example, rays of light flying at close range from massive bodies are bent. Moreover, many objects from distant space are hidden behind each other, but due to the fact that the rays of light go around other bodies, seemingly invisible objects are available to our gaze (more precisely, to the gaze of the telescope). It's like looking through walls.
The greater the gravity, the slower time flows on the surface of an object. This applies not only to massive bodies like neutron stars or black holes. The effect of time dilation can be observed even on Earth. For example, satellite navigation devices are equipped with the most accurate atomic clocks. They are in the orbit of our planet, and time is ticking a little faster there. Hundredths of a second in a day will add up to a figure that will give up to 10 km of error in route calculations on Earth. It is the theory of relativity that allows us to calculate this error.
In simple terms, we can say this: General Relativity underlies many modern technologies, and thanks to Einstein, we can easily find a pizzeria and a library in an unfamiliar area.
