# What is gravity exactly?

I once asked for Quora English.I didn’t came out. He had to deal with the curvature of space they told me. At least it was not an energy, because then the earth would slowly radiate completely by its gravity. I hope that a physicist can really explain it to us and then immediately get magnetism.

**The force that is caused by the curvature of space time (metric).**

*This is quite a bit to explain in one answer in full, but* ** If you have any questions I like to hear it.**

**A short simplified explanation:**

Something with mass or plain mass has no attraction, but causes curved space time.This means that spatial coordinates and coordinates are stretched over time as it were; They come further from each other.

Space time is 4 dimensional and is therefore impossible to depict or visualize.

There is always 1 or 2 dimension missing. As in the picture.

But because of this curvature, everything a volume and mass (an object) has a difference in the forces that work on the object.And this starts to move the object. On one side of the object is more “pulled” than on the other side. On the one hand, the curvature (or slope for a possibly somewhat easier performance) is steeper than on the other side. These are called tidal forces.

Once something is moving, this follows the Geodets** **(**geodeet (mathematics)-Wikipedia****) **of the space time geometry.See image.

So it falls e.g.The rain down. **This is what we call gravity.**

*Anything that has no resting mass can not exist at rest and always moves with the cosmic speed limit C (the speed of light.*I would rather call it the speed of causality, but good). This also follows the geodesics of the space time geometry.

*The existence of tidal forces is also the reason that we see (now still) only one side of the moon.*

Hopefully another enlightening picture:

Left the tidal forces (difference in gravity is zero) where the arrows follow the geodesics of the space time.

Right the tidal forces (difference in gravity is not zero) in an object.

The confusion in the given (fine) answers already indicates it.

We do not know.

We know very accurately what the effect is, where it is caused by (stress energy tensor), the right side of the general relativity equation, say Mass, we also know what it does: the space time curves.Incidentally, there is quite a lot to look at, you need quite a bit of mass to get a noticeable curvature.

The staff were very friendly and helpful.What gravity is we do not know.

Carel

**I often find the answers of others better than my own contribution, which has a reasonable copy-paste content.**So that first read, damn! The gravimetric force of my contribution does not do justice to them.

What Gravity is?No one knows that, but we are fortunate to know quite a lot, where we can work both practically and theoretically. One is still working on the field theory of everything. The wet dream of every physicist.

*Simply put: This is a theory in which all known natural forces are described with a theory in which the basic quantities are fields, which live on a certain background.* Wikipedia

O. K, that’s a techno-chat that I barely understand myself.One simply wants to know how forces like O. A gravity and electro-magnetism relate to each other and the whole. How everything should fit together in one solid theory.

**Gravity is indirectly caused by mass.** Those causes curvature in the space time.This curvature creates tidal forces which is a change of gravity from place to place.

This is relatively small compared to e.g. electro-magnetic forces.Furthermore, we are also busy studying gravitational waves and the theory of Gravitones, which gives each particle gravity, or in other words:

*The graviton is a hypothetical elemental particle that conveys gravity in most quantum gravity systems.*To do this, gravitones must always attract and attract over every distance. So far, gravitones have not been observed. Wikipedia

The special thing about gravity is that all particles (including photons and antiparticles) exert a pulling force that is proportional to their mass (= energy) regardless of their structure, there is no negative ‘ gravitation charge ‘, there is only one Kind of charge.This unlike electricity, there are two types, + and-loads that attract and neutralize each other, all particles with + (or-) charge repel each other. Or strong interaction, there are three types of charge which is indicated by ‘ color ‘, three particles of different color neutralize each other.

But now continue with gravity.Gravitation is independent of the nature of the mass and the acceleration by gravity is indiscriminate from acceleration by exercising any other force (equivalence principle). This together with the special relativity theory led Einstein to the conclusion that mass deforms the space itself and resulted in its field equations.

From the fact that in the universe not all matter is on a job, you have to conclude that gravitation has a dynamic counterpart.That counterpart is the expansion of space. At the beginning of the universe, this expansion was very strong during the inflation era. The Einstein field equations can easily be adjusted by adding a ‘ cosmological constant ‘.

Best, I will do my utmost to explain this matter as well as possible.

Gravity is the first to do with the mass V/d planet you are on.And the mass is that the space-time “curves distorted” if you as an example truss a cloth (is supposedly the space) on the Four Corners and you do a round weight in it will bend the cloth down and in the middle, let us say that this is the sun , another weight B. V, the earth will roll down to the other weight the sun. (gravitational force or attraction) Now I’m going to do a second force, the Force V/d centrifugal force.

The one force wants to fall to the center of the Sun, the other force wants to leave the space. These two forces make sure that the object does not choose either, and keeps turning nicely around the sun.And this law is valid throughout the universe.

If you ever see images of the astronauts in the space station I. S, then people often say that are not floating, this is not right, those astronauts are in free fall just as their space station is in free fall and also all loose parts , and water always forms a spherical shape.More importantly all the weight is now zero, also the mass, but not on weft, but here I do not go into it now.

Now back to space-time, this is to say that space is distorted by mass but also time, by Einstein’s laws we know by measurements with Atom clocks that also time is influenced by the curvature V/D space.As a test, two Atom clocks are synchronized (so set to zero) the Atom clock 1 stays on the earth, Atom clock 2 goes high in space as one 20,000 meters high in an airplane that rotates laps for a certain time, as the plane lands with Atom clock 2 Being compared to the Atom clock 1 that has remained on earth (at sea level) and what turns out the Atom clock 1 lags behind and Atom clock 2 runs before, so the farther your V/d earth is gone the younger that you stay. (These are nanosecond, 1 billionth of a second, this is on a lifetime nothing) Einstein had already calculated and predicted this, which again was a testament to the genius he was.

Gravitational attraction are basically the same.

Weight and mass is actually also the same.Weight is mainly used in the popularly.

The scientific expression for weight is mass, both mass and weight are often expressed in kilograms.

Gravity is the force exerted on every object on Earth in the direction of the core of the Earth (thus actually the attraction between two objects) This ensures that we do not come in free.

In everyday life mass and weight are used interchangeably, but this is from a scientific point of view incorrect.

Massa is a physical greatness and indicates a property of matter, with Gram as a unit.

Gravity is a pulling force that two masses exert on each other.

Because of the large mass of the Earth (gravity increases with a larger mass), everything on Earth is drawn to the center of gravity of the Earth this is the acceleration of the trap.

The acceleration in Vacum is 9.81 meters/second squared.

If an object in vacuum is released from standstill, it has a speed of 9.81 m/s after 1 second, after another second 19.62 m/s, etc.

Furthermore, also due to the rotation of the Earth, there is a corioliskracht, which ensures deflection if the trap is not purely vertical. The Corioliskracht is always perpendicular to the speed and is directly proportional to its size.

This effect is accurately demonstrated with Foucault’s pendulum.

It is seen in the University of Koblenz and in the pantheon of Paris.

As well as the centrifugal force and gravity, the Corioliskracht is proportional to the mass.

In other celestial bodies, there are totally different values for the acceleration of the trap.

For example on our sun is the fall velocity 274 m/s2 and the escape speed 619.3 km/s

I think I’ve let myself go….

Greetings, Ronny

To be short, gravity is the attraction between massive objects.It is one of the four fundamental forces of nature.

The longer version is evenly also a lot more complex.The best theory we have so far for gravity is that of Einstein, the general theory of relativity. This actually suggests that gravity comes through an apparent acceleration in 3D space as projection of 4D space time (this is, according to the equivalence principle, indeed equal to a gravity ‘ force ‘). That acceleration comes through curvature in the 4D space time which in turn comes again due to the presence of masses.

To go Short has a straight line in that 4D space time than a curved projection in 3D space, whereby for example photons do not go into a straight line in 3D space in the presence of masses (think gravitational lensing).

Thought experiment: Think of an elevator that accelerates up.In that system, a photon will not go horizontally from wall to wall, but deflect down. Because of the equivalence principle, we can conclude that the same thing is done by gravity, and so that space time is bent by mass. Then it follows a complex distraction for the actual gravity that is experienced, but it is very complex. I will probably come across this in the third year of my study.

Mr.A. Einstein has given the best description to date along with some predictions of some experiments that turned out to be correct. It is realized that there is still some to manked but so far no one has managed to give a better description with predictions of results of certain experiments.

Attraction of the mass of bodies (objects) on **each other**.

You draw exactly as Earth as the Earth draws to you.By difference in size you notice the one more than of the other.