Firstly, I am no physicist. I am just a web application programmer who has been contemplating the universe for about a week. I may be wrong about a lot of things here, but please try to look at the theory as a whole and fill in the science and physics that you know and see if they fit. I copied this from messages I composed to a friend this morning and I had new ideas as I progressed, so it might be a big mess. The core part of my theory is that buoyancy is not caused by gravity, but is instead gravity is a result of buoyancy, and that everything, even light, has even sometimes immeasurable amounts of mass and buoyancy. Edit: I'm having second thoughts about the buoyancy of energy, but I do believe that light does have a medium through which it travels, we just can't detect it unless you count gravity's effect on light as detecting it. Edit: For this theory to work, then the universe must be finite. I believe the theory that the universe is torus shaped (I previously mentioned this at the bottom of this post) to be correct and that everything in the universe is constantly moving towards the center in one direction forever to expand and contract. The contraction of the universe causes pressure as it moves toward the center and this is driving force of the buoyancy (for lack of a better word). Here is a great video illustrating this concept http://www.youtube.com/watch?v=EKtevjrZOGs This is pretty hard to explain, but think of a balloon that you blew up with helium last week. It is now on the floor and has no more helium inside because it escaped. Now think of that balloon as a structure containing dark matter. I wouldn't be able to contain it for long if it could at all. Dark matter particles are so small that they have no trouble permeating the balloon. Now think of a metal container like a gas can. It is able to hold it's shape because the pressure inside it and outside of it are equalized and it's structure allows it to hold it's shape. What happens when you quickly cool the air inside the can? It collapses because the pressure outside is greater than the pressure inside. What about if you put the same container in the vacuum of space with the lid open and then closed it? What is it filled with? Nothing that it can "contain", but instead its filled with radiation that permeates it (this is my guess). Now think of everything in the universe being filled with substances that are trying to escape and expand, causing an inequality in pressure that sometimes is greater than the force that enables an object to hold it's structure and causes it to collapse. This is observed as the force we call gravity. Now let me explain why I also think that reason gravity can slow time is that it makes space more dense. It's extremely hard for me to describe what I mean, but the illustrations that you find that depict how a planet warps the space around it with its gravity all show the space expanding, creating more distance between 2 points than there would be without the presence of gravity. I believe that instead of expanding space around it, a planet compresses space with its gravity, making it more dense. I we were using light to measure the effect of gravity, both theories would have the same effect on the length of time it would take for light to travel the same "distance". ----- Edit: I was thinking about the space warp illustrations this morning when I realized that they do illustrate an increase in density, they just try to illustrate it on 1 plane being stretched like in this image: Please Register or Log in to view the hidden image! I think that images like that one are very confusing to someone just learning about how gravity affects space-time because it looks as though distance is increased. None of the things I've read mention density change when it's obvious that's what is happening when we look at it from another angle. When viewed from above, that warp would look something like this: View attachment 6315 This video does a pretty great job of illustrating the warp of space in 3D: http://www.youtube.com/watch?v=a7uTKwbsFtg ------ This would also mean that light has density, but it is one of the least dense substances known to exist. Electrons would likely be even less dense, but I suppose they could have arguably the same density as a photon, but be smaller. There would need to exist at least 1 more substance that is less dense than a photon in order for my theory to be correct. The easiest way to visualize my theory is to think if a bottle filled with a few colored liquids of varying densities. The most dense would be at the bottom, the least dense at the top, and the other in between in order of density.(realize that there is more to it than that, but density is the primary reason) This would be how it works for everything in the universe. Now, that substance that is less dense than a photon needs a name. Lets call it Dark Matter Since the universe isn't layered like the bottle filled with liquids of varying densities when they have all settled, that means it's all mixed up. We can shake the bottle to simulate this. It will take time for the liquids to settle. During this time, the least dense liquid will be mixed around the with all of the other liquids, much like dark matter would be mixed in with the other substances in the universe. Each liquid will take a varying amount of time to settle based on their viscosity, which is governed by the strength of inter-molecular forces and the shape of their molecules. It is not only their viscosity that governs the time it takes for the liquids to settle, but also the amount of difference in the density between the liquids. Friction is also a factor Now, take this knowledge and apply it to the entire universe Dark matter would be like the lease dense liquid with the least viscosity. Light would be the 2nd. This would mean that dark matter can technically move faster than light This also means that the speed of light is limited to the speed at which it can permeate dark matter The more densely packed the dark matter is, the slower light (and everything else down to their smallest particles) can move That's why nothing we know of can travel faster than light and also why time dilation occurs Now I just need some physicists to use this idea to prove the other theories One thing that I think supports my theory very well is the theory that the universe is shaped like a doughnut. If my theory is correct, that would mean that the universe is contracting, not expanding (although both would appear to have the same effect). The center of the doughnut would very dense, while the outermost edge would be the least dense. If everything in our observable universe is moving towards the center of the donut, then everything would be getting more dense, supporting my theory that the universe is contracting. Edit: The half of the universe moving towards the center of the torus is contracting while the half moving away is expanding. It may be possible that the half that is moving away from the center experiences time increasing in speed. If so, then if we could shoot a light beam all the way around through the torus without its source moving while the light beam was traveling, would the light beam display any evidence of red or blue shift? What do you all think about this theory?