Friday, March 21, 2014

Spacetime Curvature


According to General Relativity, gravity is caused by a curvature of spacetime. Earth’s mass distorts the spacetime surrounding it, causing objects to accelerate toward Earth. So if I’m holding an object in my hand and let it go, the curvature of spacetime between the object and the Earth causes the object to accelerate downward.
We’re all familiar with (I assume) the picture of Earth sitting at the center of a dip in a tablecloth or a grid or what have you, which is often used to illustrate how Earth warps spacetime.
Now, I have issues with this view of gravity, since some sort of force is still needed to send an object moving “down” the curvature toward Earth. Otherwise, if I let something go, as described previously, why does the object not just “sit” at a point on the curvature? What makes it go “rolling” down the curvature toward Earth, which we see as gravity? It seems to me that the standard relativistic explanation is no explanation at all, because you still need some sort of force to set the object “rolling” down the curvature.
Now think of this. The Earth is moving through space (allegedly). So theoretically, someone could say that that answers my question about the curvature. Earth moves toward the object I’ve just released, mimicking gravity. But again, this explanation is obviously flawed, since it then negates the need for spacetime curvature to explain gravity. Also, it only works for objects that are in “front” of the Earth, in its path. Objects “behind” Earth, when released, would recede from Earth, or rather Earth would recede from the object, giving the appearance of anti-gravity. Also, this attempted explanation doesn’t work because the object in question already shares the (alleged) motion of the Earth due to classical, Newtonian physics. So there’s not the slightest hope of an explanation here. Absent gravity, if I let go of an object, it will continue in motion with the Earth, appearing to hover next to my hand. Which is precisely my point with the spacetime curvature explanation as well. What makes the object accelerate “down” the curvature?
Anyway.
In General Relativity, the cause of gravity is attributed solely to spacetime curvature. Let’s ignore my question as to what causes an object to accelerate down the mass-induced curvature, and just accept that curvature somehow translates to acceleration, which we view as gravity, and that spacetime around Earth is curved.
And here is where I’ve been going with all the above:
Earth is allegedly in motion. This means, obviously, that the spacetime “dimple” in which the Earth sits is moving through spacetime as well. What this means is that the edge of the dimple in the direction of the Earth’s motion is sort of “bowing in,” for want of a better description, while the edge of the dimple “behind” Earth is “springing back” into its standard position.
In other words, if gravity is due to curvature of spacetime, and Earth is in motion, then, depending upon whether an object is fore or aft of the direction of Earth’s travel, the spacetime curvature between that object and Earth is warping in a different “direction.” On one side of the Earth, spacetime is warping, while on the other side, spacetime is unwarping.
See, the spacetime curvature around Earth is not static. For an object to the fore of Earth, the spacetime curvature between it and the Earth is warping “downward,” while for an object to the aft of Earth, the spacetime curvature between it and the Earth is warping “upward.”
As an analogy, think of two buoys in the water, with a wave moving past. The buoys will not bob up and down in tandem. First, one buoy will bob upward as it encounters the wave. When it reaches the crest, it will begin bobbing back down, even as the second buoy begins bobbing upward.
So at any given time, the spacetime curvature between objects ahead of Earth and behind it is not equivalent. To the fore of Earth, the curvature is “bobbing upward,” while to the aft of Earth, the curvature is “bobbing downward.” Or vice versa.
In a static model with a motionless Earth, the curvature would be equivalent all around Earth. But in a dynamic model, with a moving Earth, the curvature is not equivalent all around Earth. And it’s hard to believe that this lack of equivalence in curvature would not have some sort of noticeable, measurable effect on the force of gravity.
(I know, I know. Gravity is not a force, according to relativity, but rather a curvature).
What I take this to mean is that the force of gravity acting on an object to the aft of Earth will be weaker than the force of gravity on an object to the fore of Earth.
Of course, the Earth is allegedly rotating, which complicates the picture. But not beyond hope of reducing the “noise” to detect the difference due to Earth’s motion.
But I predict that a satellite in a stationary position in the direction of Earth’s alleged motion, not rotating with the Earth but traveling at the same speed, such that it maintains a constant distance from Earth while remaining within Earth’s path through space, will measure a slightly stronger force of gravity than will a satellite in a similar position trailing Earth through space.
Here is a more refined prediction: at any given location along the equator, the force of gravity will be strongest at local dawn, and weakest at local sunset. Or vice versa, depending upon whether an increasing warping of spacetime corresponds to increasing gravity or decreasing gravity.
Of course, this increasing or decreasing warping could manifest as some property of gravity other than strength or weakness. If what we experience as the “attractive force” of gravity is curvature or warpage, then a dynamically-changing warpage could be some other gravitic property that we haven’t yet discovered.
Anyway, moving on.
The view or model that I’ve put forth in the preceding is basically this: we have a spacetime Point A that lies ahead of Earth in its orbit. As Earth approaches this Point A, A will begin warping, curving. Point A’s warpage will increase until it reaches a maximum when it is aligned with the center of the Earth. Once Earth’s center begins moving past point A, point A’s warpage will begin decreasing, until it reaches its “default” warpage, i.e. it will return to the state it was in before Earth’s approach.
Now, the relativist will object that I’m taking an absolutist view of spacetime. The real model should be this: the spacetime Point A, rather than being embedded in an absolute space as I’ve described, is actually just a point which maintains a constant distance from Earth. Thus, all the way around Earth, we can imagine a variety of such points, whose curvature or warpage depends only upon their distance from the center of the Earth, which remains constant.
In this relativist view, if we adopt the perspective of an outside observer, say one attached to the Sun, we will see Earth moving through space enshrouded by a “cloud” of spacetime points which maintain a constant position relative to the Earth.
In other words, in my absolutist view, Point A is embedded in an absolute space, with a constantly changing position relative to the moving Earth, while in the relativist’s view, Point A moves along with the Earth, maintaining a constant position relative to the Earth.
In the relativist’s model, spacetime around the Earth will not be dynamic as I’ve described. It will be static. The relativist simply says that at any given distance from the Earth (or any massive object), each point in spacetime will have a slightly different degree of curvature, but the degree of curvature does not change, nor does the position of the spacetime points.
In my absolutist model, Earth (or any massive object) is moving against a backdrop of spacetime points, and the curvature of these points changes as Earth (or any massive object) moves past. Some points are warping, while others are unwarping.
So in the absolutist model, the position of spacetime points can change with respect to massive objects, while in the relativist model, the position of spacetime points cannot change with respect to massive objects. But both models agree that spacetime points can have differing degrees of curvature.
In effect, the absolutist model holds that gravity (spacetime curvature) is absolute, while the relativist model holds that gravity (spacetime curvature) is relative. In the latter model, spacetime curvature is relative to whatever massive object is under consideration.
These are the only two options I can see. Spacetime curvature is either static and carried along with an object and is not connected to anything external, or it is a dynamic effect in an elastic medium. Put another way, we can imagine a bunch of boats moving about on a lake, causing ripples in that lake as they move; or we can imagine a bunch of boats, each of which is surrounded by its own ripples, but there is no water and there is no lake.
But if we look at the usual descriptions or illustrations of curved spacetime as put forth by the relativists themselves, it is apparent that they’re looking at spacetime curvature from the absolutist viewpoint. In which case, there MUST be some difference in gravity depending upon whether gravity is measured in the direction of Earth’s motion, or opposite the direction of motion.
Of course, the relativist will say that there shouldn’t be a difference, since that would mean that we’ve detected absolute motion. In which case, they will be forced to abandon the standard illustrations of spacetime curvature, such as the oft-used illustration of Earth rolling across a flat, grid-lined surface, with the grid lines curving downward as Earth rolls across. You know the one I mean.
Adopting a relativist view of spacetime curvature also forces us to abandon the assertion that spacetime curvature is dynamic, or changing. Think about it. If the spacetime Point A remains at a constant distance from Earth, and curvature equals gravity, then in an absolutist model, the curvature of Point A cannot change, for if it did so, the gravity at a specific distance from Earth would be constantly increasing, and would soon reach infinity. In other words, a relativist view of spacetime curvature does not work. The only way a curved view of spacetime is feasible is if we allow that Point A changes its position relative to Earth, and its curvature either decreases or increases depending upon whether its distance from Earth is increasing or decreasing. The only way for gravity to stay the same at all points is if one point receives a certain degree of curvature, then moves aside and another takes its vacated position, receiving the same amount of curvature.
There must be a continual cycling of spacetime points, or else the strength of gravity at any given location will quickly spiral beyond all physical possibility.
So the standard relativistic explanation of gravity as spacetime curvature demands that we adopt my absolutist model, which leads us to the detection of absolute motion, which leads us to the destruction of relativity (special relativity, at least). 
So let’s say that we perform experiments and find that there is no difference in gravity when measured from the direction of Earth’s motion and the opposite direction. What would such lack of difference mean? It would mean that relativity is not a correct theory. And if such a difference were detected, it would mean that special relativity at least must be rejected, since absolute motion has been detected.
Either way, relativity is once again doomed.
OK. FORGET the part above about gravity constantly increasing and spiraling to infinity. I see my error there now. But this is exploratory writing, after all. I’m trying to clarify my thoughts here, and follow them to where they’re leading. But I’m leaving the error in case maybe later I decide I was right in the first place.
But - to continue - the spacetime curvature at Point A or any other point still cannot remain static. The curvature has to be able to change. For instance, let’s say we have a Mass B sitting at a distance from Earth, stationary relative to Earth. Ignoring the principle that the gravity of every object is felt throughout the entire universe, there is a point where Earth’s gravity is essentially negligible and Mass B will basically be in a non-gravitating, “ground” state where Earth has no influence on Mass B. For ease and the sake of this argument, we’re also pretending that all other nearby masses aren’t affecting Mass B. Now, unless we’re subscribing to the absolutist view that all spacetime points are embedded in an absolute sort of “gravitational” space, there should be no reason that Mass B will be gravitationally affected by the approach of Earth. For gravitic spaces cannot be contiguous in a relativist view of gravity, because if Earth’s Point A is somehow connected with a similar Point A of Mass B, then gravitational space once again becomes absolute. So the curvature of one mass’s spacetime should not be felt by another mass.
Therefore we’re forced back to my absolutist model of spacetime.
Back to my Mass B. If Earth approaches Mass B and gravity works, which it obviously does, then common sense says that the Point A associated with Mass B, provided it is between Earth and Mass B, will feel the effects of Earth’s gravity before Mass B does. In other words, the curvature of Mass B’s own Point A will change. And since Earth’s own Point A also lies between Earth and Mass B, then Mass B’s Point A is actually responding to the curvature of spacetime at Point A, rather than responding directly to the mass of Earth. Which will confirm that the two seemingly relative spacetimes are actually part of one absolute spacetime, which is the medium for gravity.
From this it follows that Earth’s own Point A, rather than remaining static, must constantly be changing due to the approach of Earth. Which itself means that Point A cannot be stationary relative to Earth, but rather is behaving exactly as I outlined in my absolutist model, namely that all points are stationary and embedded in a “gravitic” spacetime, and the curvature of each point changes according the approach or recession of any given mass.
Why do I say that this proves that Point A must be constantly changing due to the approach of Earth? Because since curvature, not just mass, obviously must be able to curve spacetime, and the outer edge of Earth’s curvature first affects the outer edge of the curvature around Mass B, this can only mean that the curvature caused by Earth is advancing ahead of the Earth, curving spacetime ahead of Earth. This means that Point A, if it is on the lip of Earth’s curvature, will “drag down” an uncurved point immediately in front of it, while Point A will be “dragged further down” by a point immediately behind it and closer to Earth. Ultimately this means that if spacetime curvature truly is seen by us as gravity, then it must work according to my absolutist model.
In other words, the fact that two masses can interact gravitationally proves that gravitational space must be absolute in the manner I’ve described. Masses can’t carry their own curvature around with them in the relativist fashion. If they did, gravity would not work. And since gravity obviously works, it must be absolute the way I’ve described.
I guess it’s a bit like a wave in water. The actual wave is an abstraction; it’s a sort of optical illusion. In reality, all that exists are individual water molecules moving up and down or forward and backward, within a limited range. A wave does not consist of a mass of water molecules being swept along for enormous distances. An ocean wave itself may travel hundreds or thousands of miles, but the individual water molecules comprising it merely briefly bob up and down or back and forth, within the space of a few inches or feet.
The relativist view of gravity pretends that the abstract wave in gravitational space is the reality, when in fact the opposite is true: a portion of gravitational space merely does the equivalent of bobbing up and down as a mass passes. Or, if the mass stays in one place, that portion of spacetime stays “depressed.” Once the mass moves away, that portion of spacetime “springs back” to its normal position.
Okay. That’s my initial writing on this subject. And it’s another disproof of relativity. Experiments will either show that gravity is different depending upon whether it’s measured along the direction, or opposite direction, of Earth’s motion, thereby detecting absolute motion and disproving special relativity. Or experiments will show no difference, thereby proving that gravity cannot work as Einstein theorized, thereby disproving general relativity.
Or…experiments will show no difference, providing support for the view that Earth is motionless at the center of the universe.
Either way, relativity is doomed.
Someone may still object that the degree of spacetime curvature all around the Earth is still the same, even if spacetime curvature works as in my absolutist model. The curvature will be the same regardless of whether one adopts an absolutist or a relativist model. This is true. But such an objection misses one of my main points: in the absolutist model, there’s a dynamic other than degree of curvature at work. In the absolutist model, there is an actual absolute Point A (many more than one point, of course) past which Earth is moving.* This Point A will gradually increase in curvature as Earth approaches, reaching a maximum when it coincides with Earth’s center. Then it will begin decreasing in curvature as Earth moves away from it. In essence, on one side of the Earth, we will find a stream of points increasing in curvature as they move toward Earth’s center, or at least toward a central plane perpendicular to the line of Earth’s motion, and then decreasing in curvature once they pass the center. There’s an asymmetry which should surely be manifesting as some detectable physical phenomenon.
* It’s important to note that this point is not some sort of particle; it is not accelerating as if drawn toward Earth by gravity; it is gravity itself, or curvature of spacetime. Let’s not confuse the two. I’m not postulating a new particle here. Strictly speaking, this wouldn’t even actually be a point; it would be a relatively large region of spacetime encircling the Earth. You know, like any point at a particular distance from the Earth (which distance would constantly be changing). The curvature of spacetime in this entire region would be changing mostly identically as we followed Earth’s journey through space.
Of course, all this brings up something for further consideration: people and things that are parallel to Earth’s direction of motion, or its opposite, will be passing through warping space that is descending on them from above, or receding upward from them, depending upon which side of the planet they’re on, while people and things that are perpendicular to the direction of motion, or its opposite, will be passing through warping space that is approaching or receding from the sides. So in addition to whatever sort of effects might arise from approaching or receding warpages, we also must consider from which and into which direction the warpages are approaching or receding. Simply put, in the absolutist model, the warpages would not all converge upon the center of the Earth, or whatever mass is being considered. This should be a clue that perhaps we aren’t looking for variations in the strength or weakness of gravity in a particular direction, but rather some other property of gravity.
What other properties of gravity are there?