A Question for Curved Spacetime.

[NTuft]

32 minutes ago, J.Merrill said:

Every theory violates physical laws,

 

26 minutes ago, swansont said:

 

33 minutes ago, J.Merrill said:

Every theory violates physical laws

Bullshit. Back this up.

Are you persisting with "every", though?

[J.Merrill]

3 hours ago, NTuft said:

 

Are you persisting with "every", though?

If theories could only be Verified and never falsified they would not be theories would they. So yes with every.

[NTuft]

Every theory violates physical laws,
 

6 minutes ago, J.Merrill said:

If theories could only be Verified and never falsified they would not be theories would they. So yes with every.

Because they can be falsified does not mean they violate physical laws, rather if they're found to violate physical laws we consider them falsified? We are holding to theories that conform with physical laws, and so I do not think you can reasonably make that generalization, although I now see you declare that you're not going to go through all these theories, lucky you! 

 

Quote

The existence of matter tells space how to curve, and curved space tells matter how to move. This is layman's terms to basic principle Behind Einstein's Genius thinking and is the heart of Relativity. Einstein's successfully linked for the first time, the phenomenon of gravity with that of spacetime and relativity. If mass exist anywhere in the Universe ,spacetime around it will curve.  But depending on a few variables can affect how much. But if you take away the mass causing this Warped Spacetime, what causes the "Curved Fabric of Space"  return to its previous state,  into its unbent position?

But is the first sentence recursive?

Are you proposing that Spacetime has curvature independent of matter/gravity? That gravity is a sort of force acting on lines dictated by a dimensional geometry? Please clarify what is at issue between what you're proposing and the accepted theory foundation.

[J.Merrill]

3 hours ago, NTuft said:

Are you proposing that Spacetime has curvature independent of matter/gravity? That gravity is a sort of force acting on lines dictated by a dimensional geometry? Please clarify what is at issue between what you're proposing and the accepted theory foundation.

Gravity is not a force, all though the term Force follows gravity around through miss understanding. 

I am insinuating that Mass Causes a gradient in time. And this Curvature of time is Gravity.

 

[NTuft]

10 minutes ago, J.Merrill said:

Gravity is not a force, all though the term Force follows gravity around through miss understanding. 

I am insinuating that Mass Causes a gradient in time. And this Curvature of time is Gravity.

We are describing a force that acts on certain lines. 

42 minutes ago, NTuft said:

The existence of matter tells space how to curve, and curved space tells matter how to move.

Before you got to matter, now you are insinuating mass. Once extended into space dimension you have matter, you agree? How about extension into space imparts a curvature.

[J.Merrill]

3 hours ago, NTuft said:

We are describing a force that acts on certain lines. 

Before you got to matter, now you are insinuating mass. Once extended into space dimension you have matter, you agree? How about extension into space imparts a curvature.

I am not sure I follow, all forms of matter have mass? There are 3 physical states, Solid Liquid and Gas, all of which are matter, and can warp time and as a direct result be influenced by gravity. How do you think stars form? When temperatures are adequate things begin to take shape.

[studiot]

2 hours ago, J.Merrill said:

I'm not entirely sure how people take things so literal, the question I am proposing still stands and is still unanswered.

I think it is a very reasonable question that many don't think to ask, but I also think swansont's question was not only perfect physics, but just the question I was going to ask when he got in first.

Unfortunately I also think this thread has become rather hectic with a lot of extraneous off topic material being suddenly thrown in.
I have reversed one red mark and offer my expanded answer to your question, in exchange for your answer to one of my own.

Do you know what the moment of inertia and the product of inertia are in mechanics.

There is no catch, these provide an example of a simpler but similar mechanical effect.
GR itself is a mechanical theory.

The point is the the so called Field Equations of GR that make up GR do not only refer to a 'quantity of matter' in a local sense.
They are global equations that also refer to the distribution of that matter.

And the 'curvature' is determined by both the quantity and the distribution of the matter.

So if you 'take some matter away somewhere locally' you must move it somewhere else globally.

So the matter is then redistributed and the curvature reconforms itself to take this into account, according to the Field Equations.

 

Over to you for your reply.

 

[J.Merrill]

3 hours ago, studiot said:

The point is the the so called Field Equations of GR that make up GR do not only refer to a 'quantity of matter' in a local sense.
They are global equations that also refer to the distribution of that matter.

Sure a I would not disagree with this. 

 

In the simplest form of expression, it is described as follows.

Inertia is a measure of how difficult it is to change the velocity of an object by applying a force, and is usually expressed in terms of mass. The greater the inertia of an object for example the more mass an object has , the more difficult it is to change its velocity. Mass is different from weight though the two terms are often used interchangeably.

A more rigorous form and explanation. 

The ^MOI moment of inertia which is the amount of force needed to change the object's rotational velocity/rate.

 One could conclude that the greater the mass of the object and the larger distance from the axis, this would have a greater affect on the MOI?

The ^POI product of inertia of any object is 0 so long as the object is indeed symmetrical and the coordinate axis is also an axis of symmetry. In any case that the POI is not = to 0 the coordinate system can be adjust by rotating it until it is 0 in this case the new coordinates are referred to as the Principle axes.

Correct Me here if I am wrong please.

 

Lets make a small problem for this, lets hypothetically consider our first point mass m ( Base Ball ) which is rotating perfectly Parallel to the ground bellow it, at the distance of X from our given fixed pivot point. The MOI would be the point mass, our base Ball and this is a product of the mass and the  Distance X².  

I = mx²

If by chance there is more than one point object all rotating around the same pivot point but at different distances from the pivot. Then the total MOI of the system is the Sum of each individual MOI.

In this case I =  m_i . x_i ²

 

What if the object is something like a bat or large pole. This purposes a much more difficult problem to solve. However we could try to slice the long pole or bat into large sections each with its own incremental mass (dm) assuming each being located at a distance X from out pivot point. If we knew how the dm varied with each position we could just add them individually to obtain the total inertia of the bat or pole.

 

I = | x^2.dm

How ever not every one knows how to calculate the Mass Distribution Function dm, for any given baseball bat right off the top of their head and I'm not really sure i want to get into that here as its not needed. I have a grasp and understand as you do on how this works or at least I assume you do as well.

 

Maybe it is the context at which I choose to express things that throws people off?

For if I don't know or am unsure I can ask a question. But I do believe at this point even through the hectic topic this has formed into I have somewhat argued the same point as others, across a few topics including this one. It is never my intentions to come off as some strange individual who knows nothing at all. But it is in my nature as in most people here, to only keep questioning.

 

Back to you for your response!

Excuse any grammatic errors I am very tired here and it is late at this point will be off to sleep soon enough.

 

 

 

[Bufofrog]

5 hours ago, J.Merrill said:

The Big Bang

It violates the first law of thermodynamics, which says you can't create or destroy matter or energy. 

That is not what the first law says.  You can create and destroy matter, it happens all the time.

 

5 hours ago, J.Merrill said:

The first long-lived matter particles of any kind were protons and you guessed it neutrons. And together they make up the atomic nucleus. These came into existence around of 0.0001 a second after the Big Bang, Before that there was really no material in any familiar sense.

That of course does not violate the first law of thermodynamics.

[J.Merrill]

3 hours ago, Bufofrog said:

That is not what the first law says.  You can create and destroy matter, it happens all the time.

 

That of course does not violate the first law of thermodynamics.

What are you serious? Please read this.

The Conservation of Matter During Physical and Chemical Changes. Matter makes up all visible objects in the universe, and it can be neither created nor destroyed.

[Bufofrog]

16 minutes ago, J.Merrill said:

What are you serious? Please read this.

The Conservation of Matter During Physical and Chemical Changes. Matter makes up all visible objects in the universe, and it can be neither created nor destroyed.

That is incorrect. 

When a positron and an electron meet they are annihilated and 2 photons result from this annihilation.  The matter is destroyed.  A energetic photon can be converted into matter/anti-matter pair when in comes in close proximity to the nucleus of an atom, in other words matter is created.

[J.Merrill]

3 hours ago, Bufofrog said:

That is incorrect. 

When a positron and an electron meet they are annihilated and 2 photons result from this annihilation.  The matter is destroyed.  A energetic photon can be converted into matter/anti-matter pair when in comes in close proximity to the nucleus of an atom, in other words matter is created.

When a positron and an electron collide, they are annihilated  and two gamma photons of equal energy are emitted. You left this bit out and that has to do with energy conservation and The Conservation of Matter. You are taking things here out of context and are not fulling understanding things. You are purposing things based on an incorrect understanding of what you read.

 

Edited June 20, 2022 by J.Merrill

[MigL]

There is no such thing as a law of conservation of matter.
There is a law of conservation of energy, which holds llocally, but not globally.
It is a consequence of continuous time translation symmetry; see Noether's Theorem for details.

This provides the clue as to why energy conservation does not hold at t=0, the moment the Big Bang initiated.
Since all geodesics that make up space-time geometry initiate at t=0, time only has the forward direction, and there is no symmetry at that point, somewhat like the lines of longitude that cannot extend north of  the north pole.

[J.Merrill]

6 minutes ago, MigL said:

There is no such thing as a law of conservation of matter.
There is a law of conservation of energy, which holds llocally, but not globally.
It is a consequence of continuous time translation symmetry; see Noether's Theorem for details.

This provides the clue as to why energy conservation does not hold at t=0, the moment the Big Bang initiated.
Since all geodesics that make up space-time geometry initiate at t=0, time only has the forward direction, and there is no symmetry at that point, somewhat like the lines of longitude that cannot extend north of  the north pole.

Fair enough, and I see no reason to argue this any further. But how would you Interpret this then.

”In physics and chemistry, the law of conservation of mass or principle of mass conservation states that for any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as the system's mass cannot change, so quantity can neither be added nor be removed.” This applies heavily in GR.

 

[MigL]

Mass-energy equivalence.
Google that after you google Noether's Theorem.

[J.Merrill]

4 hours ago, MigL said:

Mass-energy equivalence.
Google that after you google Noether's Theorem.

Thank you for this.

[Markus Hanke]

5 hours ago, J.Merrill said:

Maybe it is the context at which I choose to express things that throws people off?

I just read through this entire thread, but I’m confused as to what your actual question really is. I think studiot provided a very good explanation above, though.

Could you perhaps explain again what the confusion is?

[studiot]

5 hours ago, Markus Hanke said:

I just read through this entire thread, but I’m confused as to what your actual question really is. I think studiot provided a very good explanation above, though.

Could you perhaps explain again what the confusion is?

I'm not suprised as there is far too much off topic material being introduced in this thread.  +1

 

12 hours ago, J.Merrill said:

I am not sure I follow, all forms of matter have mass? There are 3 physical states, Solid Liquid and Gas, all of which are matter, and can warp time and as a direct result be influenced by gravity. How do you think stars form? When temperatures are adequate things begin to take shape.

 

I don't see states of matter have to do with relativity?

In any even Physics recognises at least four states of matter and Chemistry several times that number.

 

13 hours ago, J.Merrill said:

It violates the first law of thermodynamics, which says you can't create or destroy matter or energy. 

 

Again I don't see any connection between Thermodynamics and Relativity.

Both Energy and Mass are frame dependent quantities.

Energy is also configuration dependent, as is mass to a lesser degree.

 

10 hours ago, J.Merrill said:

Sure a I would not disagree with this. 

So do I take the short response as meaning you have understood my answer to your title question and agree with it ?

 

10 hours ago, J.Merrill said:

In the simplest form of expression, it is described as follows.

Inertia is a measure of how difficult it is to change the velocity of an object by applying a force, and is usually expressed in terms of mass. The greater the inertia of an object for example the more mass an object has , the more difficult it is to change its velocity. Mass is different from weight though the two terms are often used interchangeably.

A more rigorous form and explanation. 

The ^MOI moment of inertia which is the amount of force needed to change the object's rotational velocity/rate.

 One could conclude that the greater the mass of the object and the larger distance from the axis, this would have a greater affect on the MOI?

The ^POI product of inertia of any object is 0 so long as the object is indeed symmetrical and the coordinate axis is also an axis of symmetry. In any case that the POI is not = to 0 the coordinate system can be adjust by rotating it until it is 0 in this case the new coordinates are referred to as the Principle axes.

Correct Me here if I am wrong please.

 

Lets make a small problem for this, lets hypothetically consider our first point mass m ( Base Ball ) which is rotating perfectly Parallel to the ground bellow it, at the distance of X from our given fixed pivot point. The MOI would be the point mass, our base Ball and this is a product of the mass and the  Distance X².  

I = mx²

If by chance there is more than one point object all rotating around the same pivot point but at different distances from the pivot. Then the total MOI of the system is the Sum of each individual MOI.

In this case I =  m_i . x_i ²

 

What if the object is something like a bat or large pole. This purposes a much more difficult problem to solve. However we could try to slice the long pole or bat into large sections each with its own incremental mass (dm) assuming each being located at a distance X from out pivot point. If we knew how the dm varied with each position we could just add them individually to obtain the total inertia of the bat or pole.

 

I = | x^2.dm

How ever not every one knows how to calculate the Mass Distribution Function dm, for any given baseball bat right off the top of their head and I'm not really sure i want to get into that here as its not needed. I have a grasp and understand as you do on how this works or at least I assume you do as well.

 

Maybe it is the context at which I choose to express things that throws people off?

For if I don't know or am unsure I can ask a question. But I do believe at this point even through the hectic topic this has formed into I have somewhat argued the same point as others, across a few topics including this one. It is never my intentions to come off as some strange individual who knows nothing at all. But it is in my nature as in most people here, to only keep questioning.

 

Back to you for your response!

 

Thank you for this lengthy response to my question.

Rather than jumping the gun a simple answer would have done.

I still do not know if you understand the difference between moment of inertia and product of inertia.

One point before I elaborate, both forms also apply to slight bending as opposed to spinning.
And surely we are talking about slight bending here rather than rotational dynamics.

Or are you of the opinion that space / spacetime is somehow spinning ?

For any given moment of inertia value there are an infinite count of configurations that possesses this value.
These are indistinguisable from the point of view of MOI.

The product of inertia contains the information of the distribution of the mass about the centre of rotation to achieve this value.
That is it selects a particular configuration.

In the 'Inertia Tensor' the product does this by including off diagonal elements, not present the the moment.

This is similar to the tensors in GR, but as I said much simplified since the coefficients in the GR tensors are themselves functions of the coordinates and not simple constants like inertia tensor.

These differences can also be show in matrix formulation, for those who, like me, prefer them.

Edited June 20, 2022 by studiot

[Bufofrog]

14 hours ago, J.Merrill said:

The Big Bang

It violates the first law of thermodynamics,

So now you see that your comment was not correct, so that's good. 

14 hours ago, J.Merrill said:

Every theory violates physical laws,

This more general statement you made is also obviously incorrect.  

[Eise]

20 hours ago, J.Merrill said:

But if you take away the mass causing this Warped Spacetime, what causes the "Curved Fabric of Space"  return to its previous state,  into its unbent position?

18 hours ago, J.Merrill said:

18 hours ago, Bufofrog said:

The answer is, that is not a physics question, that is a philosophy question.  Just like the question, "why does a positive charge attract a negative charge" is a philosophy question.

I disagree, physics derived from questioning things just like this, and to just shove aside questions like these in the physics community only shows the lack of answers.

If questions to unanswered problems is philosophy then what do we really understand, if every thing just creates another problem that cant be answered.

Where I do not quite agree with Bufofrog that philosophy is the trash can for all questions that sciences cannot answer, he definitely has a point. In philosophy, we say that your kind of question contains a category error. Causality can only meaningfully be defined in space and time. E.g. following statements should clarify this:

• a cause always precedes its effect
• Two events can only be directly causally related when they are in their immediate vicinity 

But such propositions only make sense in space and time, they are meaningless when talking about space and time. Causality does not apply to space and time themselves.

The relationship between spacetime, energy, and gravity is a conceptual one, not a causal one. By giving the conceptual relationships between these three, one could say that the job of the physicist is done. 

As a philosopher, of course one can ask all kind of petty questions ('is space really curved?';'What is ontologically first: gravity or time dilation?'). Physicists can do very well without such questions, and their possible answers. Some of these questions can be fascinating (e.g. PBS spacetime has an interesting episode about the latter question). Exactly these kind of questions show that 'causality' does not apply to spacetime itself.

[Bufofrog]

8 minutes ago, Eise said:

Where I do not quite agree with Bufofrog that philosophy is the trash can for all questions that sciences cannot answer

My comment was directed at J.Merrill's question, which was why does mass warp space.  IMO physics tries to answer how and philosophy would try to answer why.

[swansont]

16 hours ago, NTuft said:

Unclear distinction between fermions and baryons, from a short wikipedia expedition.

Fermions have half-integer spin

Baryons are made up of an odd number of quarks. Baryons are fermions. Not all fermions are baryons

10 hours ago, J.Merrill said:

What are you serious? Please read this.

The Conservation of Matter During Physical and Chemical Changes. Matter makes up all visible objects in the universe, and it can be neither created nor destroyed.

Writing something down doesn’t make it true. Did you get this somewhere? If so, cite your source.

Of course matter (and antimatter) can be created and destroyed.

9 hours ago, J.Merrill said:

When a positron and an electron collide, they are annihilated  and two gamma photons of equal energy are emitted. You left this bit out and that has to do with energy conservation and The Conservation of Matter.

You acknowledge annihilation but insist that matter is conserved…

[J.Merrill]

5 hours ago, swansont said:

Fermions have half-integer spin

Baryons are made up of an odd number of quarks. Baryons are fermions. Not all fermions are baryons

Writing something down doesn’t make it true. Did you get this somewhere? If so, cite your source.

Of course matter (and antimatter) can be created and destroyed.

You acknowledge annihilation but insist that matter is conserved…

If you would please re read the conversation. I acknowledged I was wrong in my understanding. And i thanked Migl for this insight. And I then asked a question regarding something I read, which I posted. And  frog responded accordingly I said and I quote “ I see no further reason to argue this any further “ this was my acknowledgment that I miss understood things and I thanked Migl later. I don’t feel the extra insight was needed at this point but thank you too.

 

7 hours ago, studiot said:

Or are you of the opinion that space / spacetime is somehow spinning ?

 

I think I understand what you ask here, and my answer this is no.

Although we couldn't completely dismiss the idea if someone could back it.

 

 

Edited June 20, 2022 by J.Merrill

[Bufofrog]

29 minutes ago, J.Merrill said:

If you would please re read the conversation. I acknowledged I was wrong in my understanding.

Do you now also realize that your statement that "every theory violates physical laws" is wrong.

[J.Merrill]

4 hours ago, Bufofrog said:

Do you now also realize that your statement that "every theory violates physical laws" is wrong.

Yes  recognize it as a mistake, and I can admit that, how ever it is true that every theory has its flaws and this was my point I was trying to make. 

Theories are verifiable and falsifiable.

Edited June 20, 2022 by J.Merrill