1. Originally Posted by hansda
Consider Newton's First Law of Motion , which explains inertia .

As per this law , a body(mass) in motion will remain in its state of uniform motion ; unless acted upon by some external force .

This Law holds true for a speed below relativistic speed . At relativistic speed this Law does not hold true , because frame-dragging effect will change that speed .
So you are saying free of external forces a space craft going through space at a so called Relativistic speed, it will require constant further boosting to keep the speed up.

Now this will need some evidence to support this. How did you work this out?
This would be an important factor in the science of space travel if true.

2. hansda:

Originally Posted by hansda
An experiment can be performed to find out , at what speed frame-dragging is starting to take place . Speeds greater than this speed can be considered as "relativistic speed" .
What was the result of the experiment?

Consider Newton's First Law of Motion , which explains inertia .

As per this law , a body(mass) in motion will remain in its state of uniform motion ; unless acted upon by some external force .

This Law holds true for a speed below relativistic speed . At relativistic speed this Law does not hold true , because frame-dragging effect will change that speed .
Why?

Please post the relevant mathematics so I can take a look.

3. I have searched several times to see if anyone knows whether the relativistic mass is affected by gravity, and it is difficult to find a clear concise answer to that question.

4. Originally Posted by Robittybob1
I have searched several times to see if anyone knows whether the relativistic mass is affected by gravity, and it is difficult to find a clear concise answer to that question.
Relativistic mass does not contribute to an object's gravitational field.

It would have an effect on the shape of the field, relative to the center of gravitational mass, since changes to the field propagate at $c$.

Gravitation is a function of an object's frame independent or rest mass. The following quote and reference may be of some help, in understanding the relationship and difference between mass and relitavistic mass. It does include some math but understanding what Okhum is saying does not depend on a full understanding of the math.

The Concept of Mass
... This choice is caused by the confusing terminology widely used in the popular science literature and in many textbooks. According to this terminology the body at rest has a "proper mass" or "rest mass" $m_o$ where as a body moving with velocity v has "relativistic mass" or "mass" m, given by

$m =\frac{E}{c^2}=\frac{m_o}{\sqrt{1-v^2/c^2}}$

Edit: I should have added; The whole paper is about six pages and the author's initial point is essentially that using the term " relativistic mass" is confusing and not often used except in lay publications, textbooks and some historical context.

5. Originally Posted by OnlyMe
Relativistic mass does not contribute to an object's gravitational field.

It would have an effect on the shape of the field, relative to the center of gravitational mass, since changes to the field propagate at $c$.

Gravitation is a function of an object's frame independent or rest mass. The following quote and reference may be of some help, in understanding the relationship and difference between mass and relitavistic mass. It does include some math but understanding what Okhum is saying does not depend on a full understanding of the math.

The Concept of Mass
... This choice is caused by the confusing terminology widely used in the popular science literature and in many textbooks. According to this terminology the body at rest has a "proper mass" or "rest mass" $m_o$ where as a body moving with velocity v has "relativistic mass" or "mass" m, given by

$m =\frac{E}{c^2}=\frac{m_o}{\sqrt{1-v^2/c^2}}$

Edit: I should have added; The whole paper is about six pages and the author's initial point is essentially that using the term " relativistic mass" is confusing and not often used except in lay publications, textbooks and some historical context.
That is interesting in that “m” is the relativistic mass.

So take a look at the gravitational attraction between the Sun and the Earth, and it is dependent on the mass of the Earth and the Sun. The Sun is thought of as being fixed, but the Earth is orbiting the Sun, it is never at rest. So is the mass used in the calculation already is a relativistic mass?
When calculating the Earth - Moon system where the Moon orbits the Earth, we use the same mass value for the Earth yet this time it is the Moon that is doing the orbiting. So that would mean to me at least that the relativistic mass is an actual mass and it has gravitational attraction.

You start off saying it is not involved but I could not see the reason you came to that conclusion. Sorry.

What would be the difference in mass of the Earth if the Earth was at rest?
http://en.wikipedia.org/wiki/Earth's_orbit
The orbital speed of the Earth around the Sun averages about 30 km/s (108,000 km/h)
Speed of light 300,000 km/s so if my math is right, that means the speed of Earth is 1/10 thousandths of the speed of light.
Plugging these into the above equation, where the calculated mass of the Earth = 5.9742 × 1024 kilograms
Gives Earth rest mass of 5.9739013E+24 kg
A difference of 2.9871747E+20 kg

6. Originally Posted by Robittybob1
That is interesting in that “m” is the relativistic mass.

So take a look at the gravitational attraction between the Sun and the Earth, and it is dependent on the mass of the Earth and the Sun. The Sun is thought of as being fixed, but the Earth is orbiting the Sun, it is never at rest. So is the mass used in the calculation already is a relativistic mass?
When calculating the Earth - Moon system where the Moon orbits the Earth, we use the same mass value for the Earth yet this time it is the Moon that is doing the orbiting. So that would mean to me at least that the relativistic mass is an actual mass and it has gravitational attraction.

You start off saying it is not involved but I could not see the reason you came to that conclusion. Sorry.

What would be the difference in mass of the Earth if the Earth was at rest?

Speed of light 300,000 km/s so if my math is right, that means the speed of Earth is 1/10 thousandths of the speed of light.
Plugging these into the above equation, where the calculated mass of the Earth = 5.9742 × 1024 kilograms
Gives Earth rest mass of 5.9739013E+24 kg
A difference of 2.9871747E+20 kg
I appologise, Robittybob1. I should have included the next paragraph from the reference in my last post. Which is and pay attention especially to the sentence in bold.

As I will show, this terminology had some historical justification at the beginning of our century, but it has no rational justification today. When doing relativistic physics (and often when teaching relativistic physics), particle physicists use only the term "mass." According to this rational terminology the terms "rest mass" and "relativistic mass" are redundant and misleading. There is only one mass in physics, m, which does not depend on the reference frame. As soon as you reject the "relativistic mass" there is no need to call the other mass the "rest mass" and to mark it with the index O.

The point is that there is only one real mass. The frame independent "rest mass" of matter. Note that when relativistic mass is defined as, $\frac{m_o}{\sqrt{1-v^2/c^2}}$, there is both a mass component and a velocity component. The only part of relativistic mass that, IS mass, is the rest mass.

Relativistic mass is a fancy way of describing momentum. It has nothing to do with gravity.

7. Originally Posted by OnlyMe
I appologise, Robittybob1. I should have included the next paragraph from the reference in my last post. Which is and pay attention especially to the sentence in bold.

As I will show, this terminology had some historical justification at the beginning of our century, but it has no rational justification today. When doing relativistic physics (and often when teaching relativistic physics), particle physicists use only the term "mass." According to this rational terminology the terms "rest mass" and "relativistic mass" are redundant and misleading. There is only one mass in physics, m, which does not depend on the reference frame. As soon as you reject the "relativistic mass" there is no need to call the other mass the "rest mass" and to mark it with the index O.

The point is that there is only one real mass. The frame independent "rest mass" of matter. Note that when relativistic mass is defined as, $\frac{m_o}{\sqrt{1-v^2/c^2}}$, there is both a mass component and a velocity component. The only part of relativistic mass that, IS mass, is the rest mass.

Relativistic mass is a fancy way of describing momentum. It has nothing to do with gravity.
But wasn't that what I was showing? There is only one mass for the Earth it's so called rest mass but there is no way to put it to rest, so whatever mass it has is called Rest mass, even though a component of that mass is Relativistic in origin.
We can't slow the Earth down or speed it up so its mass is its mass.
Well I'm going for this explanation until I see the results of an experiment that proves it otherwise.

8. Rest mass is not relativistic. Any 'relativistic mass', which is an outdated and dangerously ambiguous term, must be given relative to some other inertial frame.

Relativistic mass, and velocity have no meaning except as compared to something else..

9. Originally Posted by AlexG
Rest mass is not relativistic. Any 'relativistic mass', which is an outdated and dangerously ambiguous term, must be given relative to some other inertial frame.

Relativistic mass, and velocity have no meaning except as compared to something else..
When the Earth is orbiting the Sun it is relative to the Sun so that is where they get that velocity from. It does no stay in orbit unless it is going fast compared to the Sun. 108,000 km/hr is fair motoring and the energy had to come from somewhere.
Maybe there is some ambiguity when dealing with particles, for they are really only studied at rest one they smash into each other. That's more your field.

10. When the Earth is orbiting the Sun it is relative to the Sun so that is where they get that velocity from
But it means nothing in the frame of the earth and moon. That does not include the velocity of the sun relative to the galactic center. It also does not include the velocity of the sun relative to the Andromeda Galaxy. It also doesn't include the velocity of the local galactic cluster in the direction of Virgo.

Do you get the point? All velocity is relative. And that's why relativistic mass isn't really mass, it's relative momentum.

11. Originally Posted by AlexG
But it means nothing in the frame of the earth and moon. That does not include the velocity of the sun relative to the galactic center. It also does not include the velocity of the sun relative to the Andromeda Galaxy. It also doesn't include the velocity of the local galactic cluster in the direction of Virgo.

Do you get the point? All velocity is relative. And that's why relativistic mass isn't really mass, it's relative momentum.
What you don't run into problems with the "relative momentum" as you do with velocities and mass?

12. Originally Posted by James R
hansda:

What was the result of the experiment?
We know that , a ray of light bends due to the frame-dragging effect caused by the momentum of a mass .

To test this , a spinning mass can be kept in between a source of light and a screen where the shade of the spinning mass can be observed .

Gradually increase the spin and size of the shade is to be observed .

Till the time there is no frame-dragging ; the size of the shade should remain constant .

The moment frame-dragging takes place ; size of the shade will change .

So, from this we can make out at what speed or momentum ; the frame-dragging effect is being initiated .

Why?

Please post the relevant mathematics so I can take a look.
Consider the frame-dragging effect is taking place at distance 'x' between two masses m1 and m2 . Due to this frame-dragging there is a space-shift by the distance 'dx' .

At a distance x , the force F1 = G m1 m2 / x^2 .

At a distance x + dx , the force F2 = G m1 m2 / (x+dx)^2 .

This difference of force dF = F1 - F2 ; can be considered as the force generated due to the effect of frame-dragging .

13. Originally Posted by hansda
We know that , a ray of light bends due to the frame-dragging effect caused by the momentum of a mass .

To test this , a spinning mass can be kept in between a source of light and a screen where the shade of the spinning mass can be observed .

Gradually increase the spin and size of the shade is to be observed .

Till the time there is no frame-dragging ; the size of the shade should remain constant .

The moment frame-dragging takes place ; size of the shade will change .

So, from this we can make out at what speed or momentum ; the frame-dragging effect is being initiated .

Consider the frame-dragging effect is taking place at distance 'x' between two masses m1 and m2 . Due to this frame-dragging there is a space-shift by the distance 'dx' .

At a distance x , the force F1 = G m1 m2 / x^2 .

At a distance x + dx , the force F2 = G m1 m2 / (x+dx)^2 .

This difference of force dF = F1 - F2 ; can be considered as the force generated due to the effect of frame-dragging .
I doubt if that will work? Have you heard of it being tried?

The equations just show that Gravitational force varies with distance. It certaintly isn't going to show up frame dragging.

14. Originally Posted by hansda
To test this , a spinning mass can be kept in between a source of light and a screen where the shade of the spinning mass can be observed .

Gradually increase the spin and size of the shade is to be observed .

Till the time there is no frame-dragging ; the size of the shade should remain constant .

The moment frame-dragging takes place ; size of the shade will change .
According to general relativity, frame dragging occurs at any speed. What is this "the moment" you're talking about?

Also, you didn't answer my question. What speed was experimentally determined to be "relativistic"?

Is it your claim that relativistic effects suddenly switch on at some defined speed?

Consider the frame-dragging effect is taking place at distance 'x' between two masses m1 and m2 . Due to this frame-dragging there is a space-shift by the distance 'dx' .
What's a space shift?

This difference of force dF = F1 - F2 ; can be considered as the force generated due to the effect of frame-dragging .
In which direction does a frame-dragging force act?

15. Originally Posted by James R
According to general relativity, frame dragging occurs at any speed. What is this "the moment" you're talking about?

Also, you didn't answer my question. What speed was experimentally determined to be "relativistic"?

Is it your claim that relativistic effects suddenly switch on at some defined speed?

What's a space shift?

In which direction does a frame-dragging force act?
I think I get what he was meaning now. With frame dragging the lines along which distance is measured are no longer straight but curved and a curved line is longer than a straight one between the 2 points. Have I understood you correctly this time Hansda?

16. Originally Posted by James R
According to general relativity, frame dragging occurs at any speed.
I think bending of light due frame dragging occurs at a very high momentum . At any speed, light does not bend ; only curvature of spacetime occurs .

What is this "the moment" you're talking about?
"The moment" , I mean the moment at which a ray of light will bend due to the effect of 'frame-dragging' .

Also, you didn't answer my question. What speed was experimentally determined to be "relativistic"?
I did not carry out the experiment . I only had the idea of the experiment , through which the "relativistic" speed can be calculated .

Is it your claim that relativistic effects suddenly switch on at some defined speed?
This is not exactly my claim ; but my understanding that , there must be some speed or momentum where the behaviour of space will change .

What's a space shift?
'Space-shift' is physical movement of space . Space will either contract or expand .

In which direction does a frame-dragging force act?
This force should oppose the motion .

17. Originally Posted by Robittybob1
I think I get what he was meaning now. With frame dragging the lines along which distance is measured are no longer straight but curved and a curved line is longer than a straight one between the 2 points. Have I understood you correctly this time Hansda?
I was trying to predict the force for frame-dragging from 'Newtonian point of view' .

18. I think we all need to study the effects of Frame Dragging.

19. Originally Posted by Robittybob1
I think we all need to study the effects of Frame Dragging.
Frame-Dragging plays a very pivotal role in Physics ; which is not yet fully understood .

What is the cause of frame dragging ? How frame dragging happens ? What are the effects of frame dragging ? ... I think these are some of the questions for which definite answers to be found out .

What i understand is that , frame-dragging basically is space-shift ; either contraction or expansion of space .

The experiment which i suggested earlier , can give some relationship between space-shift and momentum .

20. Originally Posted by hansda
Frame-Dragging plays a very pivotal role in Physics ; which is not yet fully understood .

What is the cause of frame dragging ? How frame dragging happens ? What are the effects of frame dragging ? ... I think these are some of the questions for which definite answers to be found out .

What i understand is that , frame-dragging basically is space-shift ; either contraction or expansion of space .

The experiment which i suggested earlier , can give some relationship between space-shift and momentum .
I have a feeling it will go along way to explaining a lot of odd effects. Just a feeling, but I am going to summarise the findings so far.