More gravity...

[Eprom]

Firstly hello,

 

It is my first time posting here so hopefully I don't make too many mistakes. I have also many, many questions to ask and it is difficult to know where to start. Two particular problems have been puzzling me for quite a while.

 

The first...

Two particles of equal mass each travelling at the same near relativistic speed with one following the other and for this problem, in relatively close proximity, should also accelerate towards each other due to the 'force' of gravity. The rate of acceleration should be higher than if the two masses were travelling at non relativistic speeds. In other words the gravitational attraction between the two particles is greater at near relativistic velocities.

 

I would be interested in anything than can either prove or disprove this.

 

The second problem relates to (and possibly is part of the reasoning for the first question) the missing works describing the rate of change of space in the presence of mass. More specifically, I am able to find works related to the curvature of space-time in the presence of mass but I am unable to find any theories or examples describing or even taking into account the rate at which curvature occurs in the sudden appearance or disappearance of mass. To imply that mass curves space instantaneously and carries this unblemished curve along with it at any velocity seems absurd. To imply that on the sudden disappearence of mass that space-time curvature remains is also absurb, as is an instantaneous return to non-curved space. It would seem logical that time is involved and what ever the return rate is, it quite naturally is limited to and possible is the speed of light. To return at all implies that space-time curvature is the natural reaction to and exact balance of the presence of mass rather than a direct feature of mass. If this is true, gravitional attraction really would be a convenient twist of mathematics.

 

 

 

 

[wholloway]

The first part of this question is new to me. I would think that if gravity can travel at the speed of light then it would follow the same laws of relative motion. Wether the two bodies are at rest or moving at a high rate of speed the attraction between the two would be the same. But what if the objects are approaching the speed of light, would the gravity field start to deflect from center? If this is true then maybe you would see a diffrence. Then again maybe not. You would think both fields would deflect the same amount.

 

The second question I have been thinking about for awhile now. I think if a mass would suddenly disapear, then the gravity field would collapse at the speed of light. For a moment, until the field totally collasped, you could witness gravity reverse it self. Objects left behind would be pulled away from the center of the vanishing object.

 

Let me know what you think.

[LJG]

Interesting theory but seems unlikely. Based on my understanding of the universal state, masses and particles of matter tend to and are moving away from each other to a state of zero energy. Gravity is preventing it from accellerating at the speed of light (although this condition will end with the "big rip" ). A previous hypography "arrow of time" covered this in a reference from Devin Harris. His work has surfaced recently with the new notions about time (which are not really new, just said differently.) See http://www.everythingforever.com/index.html

 

"In science, there is a known but not fully understood point of absolute zero that is common to all physical properties. This ultimate point in nature is a zero mass, zero temperature, zero curvature (flat space), and a zero time. As I shall explain, this zero is the great attractor that begins and ends time. Essentially I explain distinctions between what I call Grouping Order and Symmetry Order. The surprising recognition is that the order of each increases in opposite directions, and thus the order of one is the disorder of the other. Consequently it becomes necessary to divide what we ordinarily consider to be simply order into two distinct contrasting types or directions. This I insist is a good hard scientific law which has a great impact on our present comprehension of nature." Devin Harris

Linda

[wholloway]

I know it seem strange, but think about what would happen if our sun suddenly vanished. If gravity does travel at the speed of light, then we wouldn't loose it's gravitational pull for eight minutes. It's my personal theory that gravity is not a wave, but a displacement of space time. I then thought that if the displacement travels at the speed of light, the moment at which we feel the affects of our vanishing sun there would be more displacment away from the center of the solor system than towards it. In this sense gravity would pull outward until the displacement settled down.

What do you think?

[Eprom]

I agree with the consideration that deflection would occur on both particles to the same extent on the proviso that the particles create the gravitational field.

 

Consider this hypothetical model:

 

Space is the hardest substance known. Although we can push things through it easily, the hardness comes from it's reluctance to allow space-time curvature. A better statement would be that space is rigid. Space-time curvature is abnormal and, according to space's simple operating principle, so is anything that causes this to occur. The most natural and comfortable state for space is total emptiness. This is in accordance with entropy. Now, if space-time is a displacement it is locally large in the presence of mass, proportional to the mass and reduces by the square of the distance from the mass - gravity. Nothing new here yet, until you attribute the effect to space itself rather than the mass. In other words to displace space requires energy - the creation of mass itself being the source. The displacement is time dependent and the rate at which displacement can occur is limited by the speed of light or perhaps more controversially, the speed of light is limited by the rate at which space can be displaced. Either way, to displace anything at all in this way implies that space can have potential energy and if it can oscillate or move, kinetic energy. If the mass could instantaneouly disappear, it would be similar to chopping the legs of a table - the table would fall. This is not so different from a collapsing eletromagentic field. In effect, shock waves would be produced, theoretically travelling either at the speed of light or the speed of gravity, the latter to include the revelation whilst writing this that they may be different aspects of same phenomena. In this way you have two distinct aspects of gravity. The potential energy in the precence of mass and the kinetic energy caused by change of mass or change of gravitional field.

 

The interesting part of this model is that it relates absolute space to local space-time. The speed of 'energy' through absolute space is constant and due to the effect of local space-time cannot be measured as different in any direction or at any velocity. The constant 'c' is determined by the rate at which absolute space can be deformed rather than determing this factor. Even if absolute space is expanding and 'c' were to change accordingly, it would still be measurable as the same constant value. Possibly this is related to the total mass-space-density.

 

In essence, this model suggests that 'space' is active, it squeezes back on mass. The model does not dissallow entropy or suggest it would squeeze all mass into the same point. It suggest to me that the properties of space are determined by the total mass distributed throughout space and the mass density in local space. Specifically, the total mass determines the total 'strain' of space and local mass density determines the 'local strain'. Gravity is endowed on space by mass and space then transfers it as 'space strain' to other masses at a constant rate.

 

Acceleration due to gravity is then an aspect of 3 dimensional strain. Transfer of energy through space could then be no more than a complex oscillating strain of various frequencies and planes of oscillation on top of a relatively static gravity strain.

 

 

 

 

Regards

I.S.

[wholloway]

I like your "squeeze" model of space time, it makes sense. If I understand it, if an object is alone in space time, the squeeze would be equall on all sides. As soon as two object come within range of each other the displaced fields would reduce the squeeze in the direction of the other object. At that point the force acting on the objects would be unequal. The objects would start to drift towards each other. The closer they get, the greater the force. Also displaced space time explains why light is affected by gravity. It's not the gravity thats acting on the light, but the fact light has to pass through a dense patch of space time. Because the speed of light is limited it takes longer to pass through compressed space. If a beam of light passes by a large mass, it forces it to curve. Like driving the right half of a car through mud. It tends to pull you in.

[Roberto]

Eprom,

 

You'd be surprised how close to the true idea of General Relativity you have gone. Indeed, in GR gravity is the curbature of spacetime due to the energy density in some region. The more the energy density in some place, more the spacetime is curved around it. But I'm afraid that your claim that a sudden disappearance of a mass body would cause an anti-gravitational pull is wrong. What would happen is that spacetime would become again flat (no gravity at all) but this change would propagate at the speed of light.

[wholloway]

Eventually there would be zero gravity, but what happens while the field is collapsing. If a mass suddenly vanished would the gravity field collapse like a magnetic field or would the field disapate from the center out. If the sun suddenly disapeared the lights wouldn't go out for eight minutes. Also we would still feel its gravity for eight minutes. What happens at the instant the field passes you by. On the side towards the sun you have zero gravity, on the side away from the sun you still have a gravity field. Does this field pull you toward it?

[Roberto]

Your sudden collapse would have a wavefront of approximately spherical shape. Every point outside this sphere would feel the gravity field as if the star were still there, every point inside would simply feel no gravity pull. There is no extra pull. If you fix something in that point of space with a nail, while it is in the outside region it feels the normal gravitational pull of the star, and when the wave front reach it and pass it, it will simply feel released from this pull.

[Aki]

I know it seem strange, but think about what would happen if our sun suddenly vanished. If gravity does travel at the speed of light, then we wouldn't loose it's gravitational pull for eight minutes. It's my personal theory that gravity is not a wave, but a displacement of space time. I then thought that if the displacement travels at the speed of light, the moment at which we feel the affects of our vanishing sun there would be more displacment away from the center of the solor system than towards it. In this sense gravity would pull outward until the displacement settled down.

What do you think?

 

I think it was from Greene's video on the Elegant Universe. It talks about if the sun vanishes, we would still see it light for another 8 minutes, however at the instant it vanishes, the earth would not be orbiting as it used to do.

[alexander]

I think it was from Greene's video on the Elegant Universe. It talks about if the sun vanishes, we would still see it light for another 8 minutes, however at the instant it vanishes, the earth would not be orbiting as it used to do.

and i think i brought it up once or twice throughout my answers here and there...

I would think that if gravity can travel at the speed of light then it would follow the same laws of relative motion.

what are you talking about? Speed of gravity is the speed of interaction between two massive objects, and by no means is it the speed of light, the estimates speed of gravity is 2x10^10 c well according to http://www.ldolphin.org/vanFlandern/gravityspeed.html research anyhow...

 

I'm actually surprised that freethinker hasn't said anything yet, but beware, he is outhere as well as Gahd...

 

I'm not that knowledgeble on gravity Tormod, Uncle, Freethinker and Gahd would be the guys to see, but this model you present seems to touch basis on general relativity and Einsteins space-time continuum theory in the curvature of space. As it says, space/time continuum curves around massive (meaning objects that have mass) objects and everything travels through it (the continuum), be that light or an asteroid.

 

Eventually there would be zero gravity, but what happens while the field is collapsing. If a mass suddenly vanished would the gravity field collapse like a magnetic field or would the field disapate from the center out. If the sun suddenly disapeared the lights wouldn't go out for eight minutes. Also we would still feel its gravity for eight minutes. What happens at the instant the field passes you by. On the side towards the sun you have zero gravity, on the side away from the sun you still have a gravity field. Does this field pull you toward it?

Well, and i think this has been said, nothing could possibly just disappear, energy remains constant, it can be transformed from one type of energy to another, but it can not just disapear...

No we will not feel its gravity for eight minutes, not even for a second...

Zero gravity? What about all that gravity that is "created" by the little, but existant mass of the Earth? What about the moon gravitational field? What will happen is the moon will crash into earth in a couple of hours(maybe more) while earth is on its way out of this system followed by a whole bunch of asteroids from the belt. To visualize, think about you swinging (or spinning in circle rather) a weight at the end of the rope, sun disappearing = you letting go.

 

I think it was from Greene's video on the Elegant Universe. It talks about if the sun vanishes, we would still see it light for another 8 minutes, however at the instant it vanishes, the earth would not be orbiting as it used to do.

 

I read about it, but dint see the video, i know that there was research done to figure out the speed of particle interaction

[Aki]

Well here's the link to the video, it's worth watching, and I find it easier to understand with visuals

http://www.pbs.org/wgbh/nova/elegant/program.html

[alexander]

Thanks Aki, I will definately take a look. I think that the link was posted on the forum already a little while ago, my problem is that Linux Firefox still doesnt have a plugin for it, or I cant find one forit anyways... But I'll try to figure something out.

[lindagarrette]

and i think i brought it up once or twice throughout my answers here and there...

 

what are you talking about? Speed of gravity is the speed of interaction between two massive objects, and by no means is it the speed of light, the estimates speed of gravity is 2x10^10 c well according to http://www.ldolphin.org/vanFlandern/gravityspeed.html research anyhow...

 

Then there is this story published five years later:::eek:

 

First speed of gravity measurement revealed

 

20:30 07 January 03 NewScientist.com news service

 

The speed of gravity has been measured for the first time. The landmark experiment shows that it travels at the speed of light, meaning that Einstein's general theory of relativity has passed another test with flying colours.

[gpdone]

Then there is this story published five years later:::eek:

 

First speed of gravity measurement revealed

 

20:30 07 January 03 NewScientist.com news service

 

The speed of gravity has been measured for the first time. The landmark experiment shows that it travels at the speed of light, meaning that Einstein's general theory of relativity has passed another test with flying colours.

 

 

This is a GOOD example of BAD science. All they proved is that a phenomenon that is the result of light speed dynamics travels at the speed of light. Big surprise! In 1915 the scientists of the time gave zero consideration to atmospheric (optical) effects. Space at that time was assumed to be a true vacuum. My FTL demo in the Science Projects forum demonstrates an effect that occurs well before optical sunrise/set and can only be a gravity effect. Modern orbital dynamics already counters such claims of light speed gravity by the popular press and the researches that allow such claims to stand.

 

Lee

[BlameTheEx]

Then there is this story published five years later:::eek:

 

First speed of gravity measurement revealed

 

20:30 07 January 03 NewScientist.com news service

 

The speed of gravity has been measured for the first time. The landmark experiment shows that it travels at the speed of light, meaning that Einstein's general theory of relativity has passed another test with flying colours.

 

 

Any chance of a link, or a quote of the whole article?

[gpdone]

Voilla!

 

http://www.newscientist.com/news/news.jsp?id=ns99993232