## What is gravitation? How is it formed? How does it attract? - by Talay Pembeci - Quora Question Review

This document contains a review of the answer by Talay Pembeci on the question in Quora: "What is gravitation? How is it formed? How does it attract?"
• The text in italics is copied from the article.
• Immediate followed by some comments

### Reflection

This question has actually been tried to be answered for hundreds of years and as a result, there are many theories as to “what is it”? Though, the theories of Albert Einstein, a German theoretical physicist of Jewish descent, seems to give the most accurate results.
why seems?
Simply put, according to Einstein, gravity is a curvature of spacetime caused because of the presence of mass and/or energy, which, as stated in another theory of Einstein, is a combination of the concepts of “space” and “time”. But, that isn’t what we should be worried about now.
I don't understand
We can better understand Einstein’s theory when we think about an example…
Okay
Let’s imagine a fabric (spacetime) which is opened and one that is stretched above the ground.
I'm lost. This is not clear.
Now, I ask you, what would happen if we put a ball on that fabric? Well, the answer is that the fabric (spacetime) would be curved towards the ball.
Sorry, but all of that is not clear.
It would look a little like this:
(It is actually to note that if we placed a particle which does not have any mass, but rather, one that is entirely composed of energy, such as an EM Wave, the fabric would be still curved.)
I don't understand this sentence. It is not clear.
Though, in the universe, the curving of spacetime is not in only one dimension (which, in the image, is the vertical dimension), but in all three dimensions of space and one dimension of time. In all these dimensions, the ball curves spacetime towards itself. This, as you can see, is a little bit (!) hard to visualize and I’m sorry to say that I don’t have an example in mind which could make it easier to do so.
If it is so difficult to explain, than TP does not understand it.
The point is, that the force of gravity, does not act instantantaneous. That means that every object at present, is not influenced by the present position of all the objects considered, but by the positions of these objects in the past. How far in the past depends about the distance and the speed of gravitation.
Thus, gravitation is the curving of spacetime which is caused by the presence of mass and/or energy.
How is it formed?
The force of gravity, the idea that all objects are attracted towards each other, is an inherent part of the objects in the universe. The same with the concept time. Both concept are inherent linked to the existance of the Universe.
Simply put, we have no idea.
In fact the question is not realistic and cannot be answered.
How does it attract?
To answer this question, let’s recall our example regarding the fabric and the ball. Now, I ask you, what would happen if we placed a marble in the region of the fabric that is curved towards the ball? Well, the marble would accelerate towards the ball and if it had no initial speed, it would collide with the ball. On the other hand, if we gave it some initial speed after we placed it, it could either revolve around the ball or escape from the ball.
as what Newton would give, except he would not mention the concepts fabric (spacetime) and curved.
Newton would also mention that the ball needs a certain speed and that the ball also 'collides' with the marble.
It looks a little bit like this:
What the picture shows is a yellow object at rest, with a small object moving through space in an ellipse. At the higest point, the furthest away, the marble moves the slowest. At the lowest point, the closest, the marble moves the fastest.
(Where the yellow object is the ball and the blue object is the marble…) This is what happens in spacetime: objects of either mass or energy curve spacetime and attract objects in it towards themselves.
The question in this picture
For instance, the Sun curves spacetime towards it and causes the planets to revolve around it, whilst the Earth curves spacetime towards it and causes the Moon to revolve around it.
But what happens when you have a cluster of stars? Each star curves spacetime and causes some stars the revolve around them, but other stars maybe not.
Hope that helps!
No it does not. The picture is too simple.
Any way, why does TP write this? Is there doubt? IMO our solar system is too simple. A better system to study are the stars around Sagittarius A*.
Source:
Relativity’s Long String of Successful Predictions/Discovery Magazine
Relativity GIFS/ Tenor

### Reflection 1 - Question Review

The answer on the 3 questions: "What is gravitation? How is it formed? How does it attract?" is in all cases more or less the same:
Take a marble, pick it up, lift it up end let it loose. The marble will drop or fall on the floor and come to rest as of nothing has happened before.
This resembles a circular process. Some one has to pick up the marble and something else causes the marble to fall. This cause is called the force of gravitation. That is all there is too understand.
However there is something more. This force is part ot the earth and in the marble. Infact it is part of every object. That means the earth attracts the marble and the marble attracts the earth (how strange that may sound).

The answer on the question follows a different route. It starts from something that is flat and this resembles a horizontal sheet. Next you place a round object on this sheet and now this sheet will be bended or curved (picture #1) . The question is why is this?

Now study the case (picture #2) with the yellow (large) ball and the blue (small) marble. What is 'strange' that the large object does not move but only the small object.
Study the same case with the yellow (large) ball and the blue (small) marble but in the slightly different configuration: both the yellow ball are of the same seize (have the same mass) and both move in a horizontal plane. The question is how do you draw the movement of both objects in óne picture of what you call space-time. IMO that is very difficult.
Considering Newton he clearly made a distinction between space and time. That means at every instant all the objects have a distinct position.

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Created: 1 June 2023

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