0. Today, dear YaPovchane, we will continue our pseudo-narrative that is equally annoying sorts of freaks and boring uporotyh labor physicists. On the explicit request of workers and other mid-level loafers (with which we ourselves are) today, we will be told what's going on with this strange gravity. There are, as usual, at least text, stupid pictures from google, epic generalizations and silence mathematical proofs.
Welcome to the area know-alls! What is gravity or why an apple falls!
1. People do not inquire in our enlightened time, why an apple falls, almost any wagged his finger to his temple and say, "Duc, it's this ... power! Attraction! .. In! .. ".
And it will be wrong. As shown and proved a famous guy named Albert, the force of attraction does not exist as a fact. And he opened it in 1916.
It all started with the fact that he invented the theory of relativity the speed of light, time dilation, non-simultaneity of two events, etc. It was very good, but just refused to work when it came to the force of gravity. And to be precise - in the presence of large masses of space, such as stars and planets.
For example, if the photon has no mass, why is a beam of light a distant star, passing by our Sun, distorted, and thus we see stars that are hiding behind the solar disk?
2. Even in the classical theory of the forces of attraction was a problem that no one could explain. That is why, for example, apple and stokilogrammovye weight fall to the ground with the same acceleration - 9, 8 m / s2? After all the calculations of Newton's force of attraction depends on the mass of the attracting body, but in practice it turns out that the free fall mass of not being. This oddity of mathematics then gracefully walked in formulas, but osadochek something left.
By the way, all the "oprovergateli" general theory of relativity actually incredible in their calculations are stuck on this point. They believe that disprove Einstein, but really talk about insolvency trials of Galileo, who was experimentally proved and that the bodies of different mass fall down with the same acceleration.
(explanation of the picture: in fact, Galileo was not dropped from the Leaning Tower of Pisa is nothing but a legend and a true popular paraphrases the essence).
3. So all Einstein did not like it. Yes, and weighing everything was very unclear. Classical physics are already two body weight: gravity (the one that we call at home weight arising from the force of gravity) and inert (the mass that we are trying to move when the body is at rest, and to devote to this effect).
Einstein loved all sorts of unusual and suggested little idea: what if the mass is actually one? The gravitational mass and inertial mass are one and the same! But what follows from this and how it explains gravity?
4. The following is a famous thought experiment with an elevator. Opponents of the theory of relativity still gloat that thought experiment, not knowing that the experiments carried out for a long time under different circumstances.
In general, the meaning is. You put in a box and asked, do you think that it is outside of the box? You definitely feel where the floor of the box, but where the ceiling to the floor because you are drawn by gravity.
You answer: box is in the world, morons! ..
And here and there - I tell you - at the moment you are flying in space with an acceleration of 9, 8 m / s2 "ceiling" box forward.
That's the whole experiment with a lift. It turns out that no experiments can not determine whether you are moving with acceleration or under the influence of gravity. Not, of course, you can make a hole in a box and see what happens, but it is not scientific. Without peeping you never absolutely prove it, you are flying or resting on the surface of the planet.
Similarly, you can not tell: Did you fall on the ground or fly in zero gravity evenly.
5. And then Einstein, have to think about the fact that the mass of only one, gave another brilliant question. What if there is no gravity?
What if the force of gravity is also the same acceleration. What if, when we jump from the second floor of the hostel, we will not fall to the ground because of gravity and fly with an acceleration towards the earth?
The question remains - why are we going and let the acceleration, but the Earth?
6. Then it will be difficult. Hold your breath, says Zadornov.
Even troechnik knows that if the body is moving along a curved path, it does not move uniformly, and with acceleration. That is, you are traveling on a straight road lisaped evenly and then toured the huge pothole on the roads of the United Russia (something we did not go skidding). Once you make the arc in order to avoid pothole, your uniform motion ceases to be uniform, and the movement of the arc you get acceleration is called centripetal.
So what we do. Falling body is not attracted by any force, but flies with acceleration. Yes, even towards the ground. If you close your eyes to the fact that there are no bumps in the path of a falling body is not present, then theoretically it appears that a falling body is really just flying in a curve trajectory.
7. Einstein thought ten years. And we have one message to tell what's what. In short, the trajectory of the falling body actually curve. It is not only the curve in three-dimensional space. A four-dimensional space, where the fourth coordinate - time.
Curves also make four-dimensional space objects have mass. The greater the mass of an object and the closer the distance to this mass, the more distorted time and space around it.
How to imagine a curved four-dimensional space? Let us remember that recently mankind believed that the earth was flat. And if you go to lisaped from Moscow to Vladivostok, never deviating, our path will seem to us a straight line. But we do not move on the plane, and the surface of the globe. What we see as a line in the plane, in space (with altitude) will look like the arc.
Old good example of geography. The shortest distance on the globe is not a straight line and an arc:
8. And in the four-dimensional space. It flies a comet in space, no one touches. But passing by the star, she falls into a curved space, and although "it believes" it continues to fly straight, however, the "curved" space leads it toward the star. If the speed of a comet (its energy) will be enough to overcome the "bias", it will fly farther. And if he was worth not enough, the comet will move on "hollow", which creates around itself in time-space, massive star. Flying very close to the star, the path of the comet and does intersect with a star and a comet will crash it. Do not forget that all this is happening in a four-dimensional space where an object has the coordinates of length, width, height and time.
9. Now let's briefly explain itself from a scientific point of view, why an apple falls.
So. Apple hanging on an apple. Sprig dries up, and the apple off the tree. What happens next?
Apple and the planets move in space (relative to the sun, the universe and all that we do not see and believe that apple is resting on the ground), and most importantly - time. Land and apple constantly moving forward. Their movement in space and time, we can say, going along parallel lines.
But regardless of the apple was an apple-tree. No force was applied to apples (no one has cast), so, in fact, it should not fly anywhere. If the Earth would not have weight, the apple would just hung in the air around the branches and is still moving in space and time along with the planet.
But the laws of our world is very strange. Our world has 4 dimensions - three spatial and one - time. If space-time there is a large mass, the space-time around this mass of deformed, distorted. As if on a flat surface of the surface of the water and threw cobblestones were waves.
The Earth has a very large mass, so the distortion of space and time is essential. And our apple continues its movement is not a straight line in a 4-hmernyh space and on curved line acceleration. And Apple is no longer flying on a parallel line, and on this line, which is due to the curvature of space leads to a collision with the Earth.
So there is a falling apple. There is no gravity, and gravity - it's just a movement along the curve path in four-dimensional space-time.
10. So much for the theory.
To date, it has been confirmed in many experiments.
Some very clever readers will ask, if gravity is a distortion of space, then why all the rush with gravitons - the particles that carry the gravity?
Despite the fact that the gravity we have explained, is still not clear why the mass distorts space. So the hypothetical culprit strain and is that the graviton, which everyone is looking for and can not find.
Gravity waves also apply not instantaneously but at a finite speed - the speed of light. If our sun suddenly disappeared, the Earth will fly along the curved space of another 8 minutes, until the disappearance of the Sun did not show up and the space is level. And then our planet will go into outer space at a tangent to its orbit.
Physicists are looking for the graviton and compose the wildest theories to justify its existence.
11. General relativity is confirmed until now experimentally and with high precision - to doubt it very rash.
Also gravity slows down the passage of time - this is also proved experimentally - the closer to the center of mass, the slower time passes. Working on the hundredth floor of aging slower than working in the mine, however, at trillionth of a second.
A fall into a black hole would look like from the infinite, because there the space is distorted so that there is hard to digest for physics state of matter known as a "singularity».
General relativity is not very friendly with quantum physics, because the use of both theories leads immediately to mutually exclusive outcomes. Someone who can reconcile the two theories, Einstein clearly become steeper and all all all. While only Hawking with his evaporating black holes showed how you can make friends in the principle of quantum physics and the theory of relativity.
That's all. Read intelligent books, including textbooks. Less politics - more science, and before you know it, after fifty years, we will have to conquer the Alpha Centauri.