What is time??

[hansda]

So you didn't actually read it then.
Try again.
But this time read the entire article, not just the bits you "agree" with.

The entire article explains about the mathematical model of spacetime . Nowhere it is mentioned that , curvature of spacetime generates force .

This is just specious uninformed double-talk to avoid realising that what you mean is spacetime is a reality.

I am not trying to talk here about spacetime , which is a mathematical model ; but i am trying to talk here about spacetime , which exists in nature and generates force .

 

[OnlyMe]

I am not trying to talk here about spacetime , which is a mathematical model ; but i am trying to talk here about spacetime , which exists in nature and generates force .

Newton described gravity as a FORCE acting between two objects.

Einstein when he introduced general relativity DISCARDED the idea that gravitation was a force and replaced it with the idea that the geometry of space results in what we experience as gravitation. Space and matter interact dynamically such that space is curved by the presence of matter. The curvature of space can also be described as the geometry of space.

This was a departure from the "flat" space and time of Newton and flat spacetime of special relativity. In a sense, the dynamic geometry of GR when mated with the Equivalence Principle, describes gravitation as essentially an inertial bias, evolving from the dynamic geometry of space. What we experience and describe as the force of gravitation is not a force, any more than coasting down a hill is a force.

The issue of space vs space + time vs spacetime, are different only if defined historically. Today they are all nothing more than different approaches and attempts to describe the same thing from different perspectives, our experience of the world around us and in the larger context of the universe as a whole.

We, almost all of us, continue to talk about gravity as a force. It is difficult to think of it differently, while we struggle against it in our everyday lives. In one sense gravitation is a ficticiuos force in a very similar way as centrifugal force is. The force of gravitation is a ficticiuos force, which can be described as an inertial bias resulting from the proximity of matter.

The difficulty in both cases, is that we have no clear definition of what causes what we experience as inertia. At least not one that is rigorously consistent with our theoretical understanding of the "forces", geometries, experimental observations and experience, that appear to be involved.

 

[hansda]

Newton described gravity as a FORCE acting between two objects.

Einstein when he introduced general relativity DISCARDED the idea that gravitation was a force and replaced it with the idea that the geometry of space results in what we experience as gravitation.

Space and matter interact dynamically such that space is curved by the presence of matter. The curvature of space can also be described as the geometry of space.

A static mass with relative to space , curves the space or not ? It is subject to force(gravity) or not ?

This was a departure from the "flat" space and time of Newton and flat spacetime of special relativity. In a sense, the dynamic geometry of GR when mated with the Equivalence Principle, describes gravitation as essentially an inertial bias, evolving from the dynamic geometry of space. What we experience and describe as the force of gravitation is not a force, any more than coasting down a hill is a force.

The issue of space vs space + time vs spacetime, are different only if defined historically. Today they are all nothing more than different approaches and attempts to describe the same thing from different perspectives, our experience of the world around us and in the larger context of the universe as a whole.

We, almost all of us, continue to talk about gravity as a force. It is difficult to think of it differently, while we struggle against it in our everyday lives. In one sense gravitation is a ficticiuos force in a very similar way as centrifugal force is. The force of gravitation is a ficticiuos force, which can be described as an inertial bias resulting from the proximity of matter.

The difficulty in both cases, is that we have no clear definition of what causes what we experience as inertia. At least not one that is rigorously consistent with our theoretical understanding of the "forces", geometries, experimental observations and experience, that appear to be involved.

 

[OnlyMe]

A static mass with relative to space , curves the space or not ? It is subject to force(gravity) or not ?

If by static you mean something like a planet or even asteroid, that has no angular or linear velocity, i.e. it is "stationary".., yes. But remember that there is no pratical way for any mass to be static or completely stationary. All objects in space have some motion when observed from other frames of reference.

The answer is yes, all objects involving mass also involve a curvature of space we experience as gravitation. They do not require motion to do so.

 

[hansda]

If by static you mean something like a planet or even asteroid, that has no angular or linear velocity, i.e. it is "stationary".., yes. But remember that there is no pratical way for any mass to be static or completely stationary. All objects in space have some motion when observed from other frames of reference.

Within the space of our earth , a mass can be at rest with relative to our earth's space .

The answer is yes, all objects involving mass also involve a curvature of space we experience as gravitation. They do not require motion to do so.

If curvature of space causes gravitation ; then what about light ?

 

[hansda]

Light doesnt bend around a static mass , which is static with relative to space .

 

[OnlyMe]

Light doesnt bend around a static mass , which is static with relative to space .

I am unaware of any proof of this. Please provide some reference.

 

[Pincho Paxton]

Light doesnt bend around a static mass , which is static with relative to space .

Is there an example of this anywhere?

 

[OnlyMe]

Within the space of our earth , a mass can be at rest with relative to our earth's space . If curvature of space causes gravitation ; then what about light ?

From the perspective of GR lght follows the geometry of space. The geometry of space near a significant mass is curved sufficiently that we are able to observe that curvature in the path of light. (Observed as gravitational lensing.)

When you specify relative to our Earth's space, you imply that our earth is "at rest" in space or spacetime. This is not an accurate statement. The earth has both an angular momentum and linear motion, in space. Due to the geometry of space around the sun, the Earth's linear motion is manefest as an orbit around the sun. The earth follows the geometry of space resulting from the dynamic interaction between the mass of the sun and space. (We call that geometric relatinship gravity.)

As to the concept of anything being at rest relative to earth while in space, here you would need to supply an example. It is possible to define something as at rest relative to the earth, if it is part of the earth or in direct contact with the Earth's surface and comoving with the Earth's motion. However, even the earth is in motion relative to "space", therefor nothing can be at rest relative to the space the earth is itself in motion relative to.

 

[Dywyddyr]

The entire article explains about the mathematical model of spacetime . Nowhere it is mentioned that , curvature of spacetime generates force .

Nothing to do with what you said.

I am not trying to talk here about spacetime , which is a mathematical model ; but i am trying to talk here about spacetime , which exists in nature and generates force .

Pardon?
You're not here to talk about spacetime but spacetime?

 

[hansda]

From the perspective of GR lght follows the geometry of space. The geometry of space near a significant mass is curved sufficiently that we are able to observe that curvature in the path of light. (Observed as gravitational lensing.)

When you specify relative to our Earth's space, you imply that our earth is "at rest" in space or spacetime. This is not an accurate statement.

Our earth moves with relative to the outer space . Our earth is surrounded by this outer space . Earth's space is within this outer space .Earth's space moves alongwith the earth . So, our earh's space is static with relative to our earth .

The earth has both an angular momentum and linear motion, in space. Due to the geometry of space around the sun, the Earth's linear motion is manefest as an orbit around the sun. The earth follows the geometry of space resulting from the dynamic interaction between the mass of the sun and space. (We call that geometric relatinship gravity.)

Do you mean to say that , space is the cause of force ?

As to the concept of anything being at rest relative to earth while in space, here you would need to supply an example. It is possible to define something as at rest relative to the earth, if it is part of the earth or in direct contact with the Earth's surface and comoving with the Earth's motion.

However, even the earth is in motion relative to "space",

Our earth is in motion relative to outer space but with relative to the earth's space , our earth is static .

therefor nothing can be at rest relative to the space the earth is itself in motion relative to.

With relative to outer space , no rest is possible ; but with relative to our earth's space , rest is possible .

 

[Pincho Paxton]

Our earth moves with relative to the outer space . Our earth is surrounded by this outer space . Earth's space is within this outer space .Earth's space moves alongwith the earth . So, our earh's space is static with relative to our earth . Do you mean to say that , space is the cause of force ? Our earth is in motion relative to outer space but with relative to the earth's space , our earth is static . With relative to outer space , no rest is possible ; but with relative to our earth's space , rest is possible .

The curve moves with us like the wake of a boat, but it isn't the same water.

 

[Dywyddyr]

OEarth's space moves alongwith the earth . So, our earh's space is static with relative to our earth

Pardon?
Evidence please.

but with relative to our earth's space , rest is possible .

What?

 

[hansda]

Pardon?
Evidence please.

There is a boundary between our earth's space and outer space . This is the boundary from where free fall towards earth's surface is possible. Beyond this boundary a mass will remain in outer space and no free-fall towards earth's surface is possible . This possibility of free-fall proves that , our earth's space is moving alongwith our earth . So earh's space is static with relative to our earth .

What?

Within this boundary of our earth's space with outer space ; if a mass is static with relative to our earth , that mass is also static with relative to our earth's space .

 

[Pincho Paxton]

There is a boundary between our earth's space and outer space . This is the boundary from where free fall towards earth's surface is possible. Beyond this boundary a mass will remain in outer space and no free-fall towards earth's surface is possible . This possibility of free-fall proves that , our earth's space is moving alongwith our earth . So earh's space is static with relative to our earth . Within this boundary of our earth's space with outer space ; if a mass is static with relative to our earth , that mass is also static with relative to our earth's space .

You mean if it circled the sun at the same speed, and we didn't spin?

 

[hansda]

You mean if it circled the sun at the same speed, and we didn't spin?

We are also spinning alongwith the earth . But relative to our earth we may be static or dynamic .

 

[Pincho Paxton]

We are also spinning alongwith the earth . But relative to our earth we may be static or dynamic .

We aren't in space though, it's different here, there is bonding, and such. In space you need a different type of bonding for drag etc.

 

[Dywyddyr]

There is a boundary between our earth's space and outer space . This is the boundary from where free fall towards earth's surface is possible. Beyond this boundary a mass will remain in outer space and no free-fall towards earth's surface is possible .

You're just making this up as you go along, aren't you?

This possibility of free-fall proves that , our earth's space is moving alongwith our earth

No it doesn't.

So earh's space is static with relative to our earth . Within this boundary of our earth's space with outer space ; if a mass is static with relative to our earth , that mass is also static with relative to our earth's space .

Did you ever have an education?


Where, exactly, would you place this "boundary"? How far away from the Earth?

 

[hansda]

You're just making this up as you go along, aren't you?


No it doesn't.


Did you ever have an education?


Where, exactly, would you place this "boundary"? How far away from the Earth?

This boundary can be related with 'escape velocity' .

 

[Dywyddyr]

This boundary can be related with 'escape velocity' .

Meaning what?
I'll ask again: where is this boundary?
If it's dependant solely on velocity then it's not exactly a "boundary" is it?
What speed do you think "space" is doing relative to Earth? How do you know?