Brent Clay

So we see that space (the actual spacetime fabric itself) is enormously stiff (or enormously fluid, but that discussion will come later), but that's not all that's strange about it. It is also expanding. This seems a rather odd coupling of characteristics. Anything that is rigid resists bending or flexing in any way, yet the Universe is clearly expanding at an enormous rate. This forces us to wonder about the nature of that expansion. When we look to the heavens and see that all of the visible galaxies appear to be moving away from us (regardless of where in the sky we look), it begs the question of  how  they are moving. This may seem to be yet another odd question. If something is moving away from us, does it really matter  how  it is moving? In fact, it does. The question boils down to this: Are galaxies moving through space like cars on an interstate, or are they being carried away like suitcases on an enormous, invisible conveyor belt? This difference is a...

Note that this post makes reference to a scale-model Solar System, which was introduced in a prior post. What does this have to do with the rigidity of space? Think of a location that is about 40 miles from where you are at this moment. Even if there is interstate highway between you and this location, it would still take quite a drive to get there - 40 miles is a fair distance. Now, imagine that the entire region around you is covered with a layer of insulating foam, which is 50 feet thick (think of something you might find in the cushions of a sofa). If you were to set a golf ball on the foam in front of you, it would have no reason to roll in any particular direction (for this example, assume that you are somehow hovering above the foam, and that there is nothing else nearby to disrupt its smooth, flat surface). Now, let's say that 40 miles away there is an enormous floating crane, which is holding a scale model of the sun (a spheroid, 36 feet in diameter) suspended in the...

Let us now perform another level-set. So far, we recognize and accept the obvious existence of matter within the Universe. Furthermore, as  E=mc 2  tells us, whether any unit of matter happens to take the form of energy or mass does not subtract from its overall qualification (or quantification) as matter. In other words, mass and energy are interchangeable; they are only different  forms  of matter. Of course, this is not to suggest that switching between these two states is a trivial thing - far from it, but that is a topic for another day. Next, we know that empty space isn't exactly empty. Meaning, in a very real sense, there is a spacetime fabric that can be coerced into forming gravity wells, or producing other observable effects such as gravitational lensing. Gravity wells then, are constructed of spacetime itself; they do not fall within the realms of matter, but have identifiable characteristics nonetheless. General Relativity actually predicts  Emb...

Once we begin considering the possibility that galactic gravity wells could somehow be independent of the matter within them, a few more questions immediately surface. Could gravity wells predate the matter within them? Why does matter seem to always  live  in these gravity wells rather than more evenly cover the emptiness of intergalactic space? Why do they rotate? And of course, what causes them? Surprisingly, none of these questions are difficult to answer within the context of our current line of reasoning. There are in fact, agreeable, and what seem to be quite plausible answers to all of them.  Note that I will not get to all of these questions within this particular post, but will eventually address each of them within this Dark Matter series . In terms of the Big Bang, all the matter in the Universe is nothing more than a debris field. On first glance, this debris appears to be remarkably evenly distributed. But on closer inspection we find that although ...

To this point we have not discussed anything new; only clarified the importance of thinking of gravity in the correct context. Rather than visualizing gravity as the attraction of two bodies, we are now thinking of bodies such as stars and planets traveling along the inside of Gravity Wells - a well-known concept. This means, we have only restated the problem in less abstract, less obscure terms. It turns out that this analogy holds up remarkably well; like rolling a marble along the inner surface of a physical bowl, it will travel around the bowl until it eventually loses momentum and settles to the bottom, or if it is tossed too hard, roll over the edge of the bowl and escape it altogether. If the marble could somehow be rolled with just the right force (momentarily overlooking friction), it could settle into a point of equilibrium, having just the right amount of angular velocity to maintain a constant distance from the bottom of the bowl and its outer edge. This perfect velocit...

These depressions in space (gravity wells) express the classical understanding of gravitation (Relativistic, not Newtonian), which suggests that gravity is not a measure of the force of attraction between two bodies, it is instead a measure of the force with which two bodies fall into the larger gravity well produced by the overlapping of their two individual gravity wells. This means that we could essentially describe the riddle of Dark Matter in another way, by simply saying that we cannot explain how the gravity depressions in which galaxies exist can be deep enough to prevent the spinning matter within them from over-spilling their boundaries. So, before tackling the question of how these depressions can exist at all, we should first ask an even more basic question. If we concede that such depressions  do  exist, then perhaps we can first attempt to understand whether the matter within galaxies behaves according to our understanding of gravitation. In other words, start ...

The paradox of Dark Matter leads unavoidably to a few questions. The first and most obvious has to do with galaxy structure. How can galaxies behave as though they contain 70% more mass than they appear to have? What keeps them from simply flying apart? But these questions quickly lead to the even more intriguing question of how they ever formed at all. Understanding the riddle of Dark Matter requires rewinding the clock all the way back to the Big Bang. Like so many other questions in physics, it can seem odd that two seemingly disconnected topics can end up having such direct bearing on one another. But in the end, unexpected connections like this often end up being a good thing; they are signals, hints that we may have tapped into a fundamental aspect of the Universe that once understood, could help resolve other mysteries as well. First, what of galaxy structure and rotation? Here the problem is that we cannot detect enough matter to account for the gravity that we know  mu...

Dark Matter is a special form of matter that is hypothesized to explain certain anomalies in the formation and behavior of galaxies, which has been the subject of a great deal of attention and debate in the areas of physics and astronomy over recent years. Over the next few weeks I plan to publish a series of posts on the subject, and along the way, propose a possible alternative to current, and prevailing thinking on the matter. The concept of Dark Matter was first put forward as a possible explanation for some of the odd characteristics of galaxies that cannot be fully explained based on current notions of gravitation. In a nutshell, it is presumed that gravity is the only binding agent that holds galaxies together. Based on this simple and reasonable assumption, it seems obvious that there must then be enough matter in any given galaxy to account for the fact that it is able to hold its shape. The problem is that given the rotation of most galaxies (maybe all), there does not se...