What if the speed of the body is multiplied by time. Search for free fall acceleration. Why is the acceleration formula needed?

Imagine that suddenly, coming from his left side, there is a photon watch in front of him, moving from left to right. The photon no longer moves a vertical path from bottom to top and then from top to bottom, but an oblique path. In fact, when a photon starts from the bottom, it takes certain time, and as the clock moves, the observer measures a longer trajectory. The same is true when a photon moves up and down. The distance traveled by a moving photon is longer than the distance traveled by a stationary photon relative to the observer.

And since the photon maintains the same speed, this means that a longer duration is measured between two "ticks" relative to the moving photon and that the seconds pass more slowly. According to the observer, a moving clock will be delayed compared to a stationary one. Imagine that a moving watch is on the wrist of an observer named Hervé. For him the situation would be mutual. He will see the delay of Henri's watch in relation to him. For him, Henri and his watch are moving while he and his watch are motionless.

Unification of space and time

Please note that the faster the clock moves, the longer the path and the longer the time between two ticks. Everyone knows what movement is; it is a large part of our daily life. Aristotle proclaimed a law shared by ordinary mortals: motion is related to the force acting on an object. In everyday life, everyone can experience this. You have to push the cart to advance it, lift the stone so that it follows the path from bottom to top. Excited by such trivial examples, you will interrupt me and ask what all these analyzes can do.

Should we really think about such everyday examples? Well, let's think: here's a cart. You put emphasis on it, with a certain force. After some time it will move and rest. During this time he will travel a certain distance. You press it with more force, again it will move, with more high speed, will move a greater distance and stop again. You want it to travel a greater distance with the same strength. You lubricate the wheels of the wheels, remove all the bumps that are in the way.

You push it again with the same force, and there it goes a greater distance. You conclude that the reason the race is stopped is because there is wheel friction on the road. You also conclude that in order to move a greater distance, you must eliminate as much friction as possible. Note that in all of these experiments the cart is pushed with the same force. Then you do what might be called a thought experiment. Einstein used it often. You imagine that you can eliminate friction completely.

Suddenly you eliminate the reason for the cart stopping. You understand that he will continue his race indefinitely at a constant speed and in a straight line. Of course, in reality you can never completely eliminate friction, that is, the force that opposes its movement and which causes it to slow down and then become motionless. But in thought, you can easily make an experience impossible to achieve a specific goal. What is the result of such an experience? First, force is not responsible for motion because with the same force you can lengthen the time an object moves by eliminating friction, which is force. opposite direction movement of the carriage and who is responsible for slowing it down and stopping it.

Force slows down or speeds up movement. Therefore, it is not responsible for the speed, but for the change in speed and direction of the body. By eliminating friction completely, you allowed the object to continue moving indefinitely, at a constant speed in a straight line. Until the force acting on it changes its speed and direction. Galileo saw that no force was required to produce linear motion at a constant speed, but it was Newton who formalized this principle. You can correctly state Newton's first law, the principle of inertia: "Every body continues at rest or uniform motion along the straight line in which it is located, if some force acts on it does not force it to change its state.”

What lessons can be learned from such an experience? First, don't trust the obvious. This one, like an unfaithful friend, betrays you at the first opportunity. Then, freed from the obvious, do not lock yourself in everyday experiences, do not hesitate to think about an experiment, and even if you cannot specifically come up with one, imagine it! This one never reveals himself naked, you need to go looking for him, and for this you need to think. Of course, you will eventually need to test your thinking results by confronting them with experience and experimentation.

But do not hesitate, theoretically, to think about the incredible, the unheard of. Of course, don't think that he needs a little effort, it requires an appetite for knowledge, a lot of work. Let's listen to Einstein, who draws the teachings of the law of inertia from a book of incredible wealth, he writes: This law cannot be obtained directly from experience, but only from speculative thought consistent with observation. Idealized experience can never be effectively realized, although it leads to a deep understanding of real experience.

Before we begin space-time travel, we must say a word about Galileo's principle of relativity. It is mainly known as a single electrical and magnetic phenomenon. In particular, he showed that electric and magnetic fields propagate in space in the form of a wave and at the speed of light. Now the wave is propagating in the material medium, at least that's what classical mechanics speaks. If you throw a stone into water, you will see the formation of waves carried by the medium of the water.

Place the bell under the glass in which you were previously evacuated, you will not hear the sound of the bell. According to Maxwell's equations and various experiments to measure the speed of light, everything indicated that this speed was constant, regardless of the movement of the source. If both cars move at the same speed, they will both be mutually stationary. And Einstein, at the age of 16, wondered what he would feel if he followed a beam of light. He will see a wave that is not moving.

Now, with Maxwell's equations, Einstein was reassured; he had never seen such a sight: a motionless wave of light. However, this constancy of the speed of light, as we have already said, contradicted the law of addition of velocities for two observers moving relative to each other. If light is a wave, what is the medium that allows it to propagate? Physicists invented a material medium through which light could travel: the ether. However, the speed of light is constant. This means that it does not move with the ether, but through the ether.

Immobile ether and through which light moves. According to the principle of relativity, the movement of constant speed is no different, we do not feel it. All laws of nature are equivalent to any relative motion. Remember Galileo's experience in his boat. Non-mobile ether means that not all observers are equally qualified to perform experiments. There will be a preferred system in which man is at rest relative to the motionless ether. This contradicted the principle of relativity.

What do the laws of nature have to do with our relative motions? There is no more objectivity of the laws of nature, no more science, no more knowledge. No, this cannot be for Einstein. Nature would be incomprehensible, inaccessible. Einstein realized that the ether created more problems than he solved, and came to the only rational solution: eliminate the ether. Light does not propagate in any medium, but in a vacuum. The laws of nature do not depend on the movements of observers. All movement is relative; absolute rest does not exist as absolute movement.

If you are measuring speed, you must know who is measuring and in relation to who or what you are measuring. Yes, the principle of the constancy of the speed of light is correct. These two principles are opposite. But why is this so? Let's return to Einstein's method. Let's pose the problems without making them too complicated. So speed is distance divided by duration. You will tell me; It's okay, we understand! This is a measure of space that separates 2 points. It is a measure of time between two events. Thus, speed is related to space and time.

In the middle of the van we put the throwers. Both balls make their respective trips at the same speed. They are launched simultaneously. For me, who is on a train, this means that the train is stationary compared to me. Two balls with the same speed, moving at the same distance, it is easy to understand that the duration of their stroke is the same and that the two balls will reach their respective wall at the same time, therefore at the same time. What happens to someone who sees events from the pier? The train is moving in relation to it.

The subtraction must be done since the ball is pointing away from the direction of the train. In fact, for those on the platform, this ball will travel a shorter route, but at a lower speed. Let's say the length of the car is 120 kilometers. So, each ball, at the beginning, is located 60 kilometers from their respective wall. Thus, this ball will move 10 kilometers per hour. For one who is on the platform, like one on a train, the two balls will reach their respective walls within one hour, and the two events will be simultaneous for one observer and for the other.

If speed is distance divided by duration, this means that both speeds and distances must be converted to find the same duration. In the example above, the speeds were not the same, neither were the distances, but the duration was the same for each observer.

In other words, time is universal and passes at the same rate for every observer. Time is separated from space; it exists independently of space. Time, that is, duration, measured in the Andromeda galaxy, two million and a half light years, remains the same in the galaxy that inhabits us, Milky Way. This is what was considered to be the theory of limited relativity. Because such measures taken in the above example are wrong. It was assumed that the distances and times measured in the carriage and on the pier should be the same.