1

**New Theories / Re: What exactly is gravity?**

« **on:**14/01/2021 17:26:01 »

SPACE TIME:

What bothers my mind is, about space time. What exactly is this space time and how masses curves this empty space. As per Minkowski space time is nothing or empty. As per Einstein space time near to the masses is curved. Gravitational lensing clearly tells us that curved space time near to the masses is not empty.

Of course it is not bending but curved space is dragging the light. In other words curved space is not stationary, it is rotating and causing the mass to move.

We are building beautiful space taking snap shots of different events and stacking up them to give us a three dimensional space time. Suppose if we take snap shots of Earth at the end of each quarter in a year at different places around the Earth, taking them as events and if we arrange them, we will get the feeling of three dimensional space time.

In ordinary space, a position is specified by three numbers, known as dimensions. In the Cartesian coordinate system, these are called x, y, and z. A position in spacetime is called an event, and requires four numbers to be specified: the three-dimensional location in space, plus the position in time.

Trampoline analogy:

“Consider a very large trampoline with nothing on the trampoline pad and trampoline pad remains flat and parallel to the ground. Now place a heavy bowling ball at the center of the trampoline pad. The center of the pad will sag downward. If we assume the analogy that the trampoline pad represents space-time, and the bowling ball a gravitating object, then the sagging of the trampoline represents the curvature of space time under the influence of gravity. We can now see that if we take a lighter ball, and place it at the edge of the trampoline pad, it will roll down toward the bowling ball. This attraction to the bowling ball is because the path toward the bowling ball through space is favorably curved”.

But is this picture right? Mariusz Wroblewski is skeptical, asking:

“I’d like somebody to finally acknowledge and admit that showing balls on a bed sheet doesn’t cut it as a picture of reality”.

I freely acknowledge and admit it. As ubiquitous as pictures of bent sheets or coordinate systems are, they aren’t exactly reflective of the reality we inhabit.

If you’ve ever seen a picture of a bent, two-dimensional grid with masses on it representing space, you’ll know this type of illustration is extremely common. It appears to depict the fabric of space as being curved by the presence of mass, and therefore, any other particle traveling along this fabric will have its path bent towards this gravitational source. But what would such a picture actually imply? If space is like a fabric, how does mass curve it?

Gravity simply is, and it’s merely that the equations that describe General Relativity are geometric in nature. The idea that mass-and-energy curves space can be right,.

The presence of matter and energy curved the very fabric of this spacetime, and that curved spacetime, in turn, dictated how matter moved.

Ok, let us imagine that: there are two key players, matter and energy. If the space is empty, how mass curved, or where from the energy is coming, source. In case if the source is mass itself, it will be different story.

The big question that bothers my mind, how a 2d space, when mass is placed converted into 3d space. 3d space implies that there is something, what is that?.

Maths is not everything, it is only an instrument or aid to help, have a better visualization of what you have said.

Yours

Psreddy

What bothers my mind is, about space time. What exactly is this space time and how masses curves this empty space. As per Minkowski space time is nothing or empty. As per Einstein space time near to the masses is curved. Gravitational lensing clearly tells us that curved space time near to the masses is not empty.

Of course it is not bending but curved space is dragging the light. In other words curved space is not stationary, it is rotating and causing the mass to move.

We are building beautiful space taking snap shots of different events and stacking up them to give us a three dimensional space time. Suppose if we take snap shots of Earth at the end of each quarter in a year at different places around the Earth, taking them as events and if we arrange them, we will get the feeling of three dimensional space time.

In ordinary space, a position is specified by three numbers, known as dimensions. In the Cartesian coordinate system, these are called x, y, and z. A position in spacetime is called an event, and requires four numbers to be specified: the three-dimensional location in space, plus the position in time.

Trampoline analogy:

“Consider a very large trampoline with nothing on the trampoline pad and trampoline pad remains flat and parallel to the ground. Now place a heavy bowling ball at the center of the trampoline pad. The center of the pad will sag downward. If we assume the analogy that the trampoline pad represents space-time, and the bowling ball a gravitating object, then the sagging of the trampoline represents the curvature of space time under the influence of gravity. We can now see that if we take a lighter ball, and place it at the edge of the trampoline pad, it will roll down toward the bowling ball. This attraction to the bowling ball is because the path toward the bowling ball through space is favorably curved”.

But is this picture right? Mariusz Wroblewski is skeptical, asking:

“I’d like somebody to finally acknowledge and admit that showing balls on a bed sheet doesn’t cut it as a picture of reality”.

I freely acknowledge and admit it. As ubiquitous as pictures of bent sheets or coordinate systems are, they aren’t exactly reflective of the reality we inhabit.

If you’ve ever seen a picture of a bent, two-dimensional grid with masses on it representing space, you’ll know this type of illustration is extremely common. It appears to depict the fabric of space as being curved by the presence of mass, and therefore, any other particle traveling along this fabric will have its path bent towards this gravitational source. But what would such a picture actually imply? If space is like a fabric, how does mass curve it?

Gravity simply is, and it’s merely that the equations that describe General Relativity are geometric in nature. The idea that mass-and-energy curves space can be right,.

The presence of matter and energy curved the very fabric of this spacetime, and that curved spacetime, in turn, dictated how matter moved.

Ok, let us imagine that: there are two key players, matter and energy. If the space is empty, how mass curved, or where from the energy is coming, source. In case if the source is mass itself, it will be different story.

The big question that bothers my mind, how a 2d space, when mass is placed converted into 3d space. 3d space implies that there is something, what is that?.

Maths is not everything, it is only an instrument or aid to help, have a better visualization of what you have said.

Yours

Psreddy