Brent Clay

There are two gravitational conditions. First is the common notion of Relativistic gravitation, which tells us that gravity is a result of the curvature of spacetime caused by the presence of mass. This form of gravity is most familiar to us. When we look up at the night sky, we are peering at the stars from deep within the earth’s Gravity Well, which also happens to be fairly deep within the Sun’s Gravity Well. Kepler’s Laws of planetary motion, Einstein’s General Relativity, and even Newtonian Gravitation all provide good frameworks for understanding what we see in the skies, especially when it comes to the behavior of nearby celestial objects like the planets in our Solar System. However, applying what we have learned about gravitation to our observations of other galaxies, especially spiral galaxies, we find that they  do not  seem to behave as we expect. As we have discussed at length, there simply isn’t enough visible matter within them to account for their abil...

We should remember that in every scenario where a substance or object succumbs to stress in a way that changes its nature (as discussed in the previous post), the principles of mass/energy equivalence remain in play, as do those of mass/energy conservation. For instance, the sun’s nuclear furnace works by compressing hydrogen atoms into helium (although, not quite so directly), resulting in a loss of mass in the form of energy. But, using the handy equation,  E = mc 2 , we can account for the mass of the original hydrogen atoms even after this fusion takes place. It is important to understand something else about mass/energy equivalence too, which is that it does not imply that mass and energy can be converted between states in some trivial way; it says that the  mass of a body is a measure of its energy content . One way of thinking about this is to consider unit of measure conversions: one gallon of liquid is equal to 3.785 liters. Although this analogy is far from perfect...

In the previous post, I discussed some of the oddities revealed in the Hubble Ultra Deep Field Image. Specifically, the strange occurrence of what appear to be galaxies of vastly different ages occupying the same regions of space, within what is believed to be a snapshot of the early Universe itself (or, at least part of it). At the end of that post, I concluded that the most straightforward solution to this mystery lies in the likelihood that these galaxies formed in place (at their relative positions) as a result of something other than the Big Bang. The next question is, if the matter from which these galaxies were formed did not originate from the Big Bang, then where did it come from? And, what triggered their formation? Let us think about the rigidity of space and Universal expansion again. As we discussed in a prior post, spacetime is incredibly rigid, but it expands nonetheless. And, despite this unrelenting and ever-accelerating expansion, the matter within it condenses into...

If there isn't enough observable matter within a given galaxy to account for the fact that it does not simply fall apart, then what explanation (other than Dark Matter) is there for its formation? Is it possible that the galaxies formed in place, at their relative positions within the Universe, rather than being part of the debris field of some enormous explosion (the Big Bang)? It seems worth considering. Of course, if we do consider it, we must then ask where all the matter  did  come from. Indeed we do. For some, this question is enough in itself to dismiss any argument against the Big Bang altogether. Yet, I must hold out that to the open-minded, considering this question is no less sensible than believing that all the matter in the Universe originated from a singularity. Speculation like this leads to many valid questions, not the least of which being, "What about all the other supporting evidence for the Big Bang?" A fair question to be sure, but that's wh...

In actuality, speculation about the origins of the Universe is very often speculation about the origins of matter. The Big Bang tracks everything back to a  singularity  – a single theoretical point where everything that  is  today, at one time existed in a condensed, ethereal state, which eventually exploded and evolved into the Universe as it is now. Given our observations and reflections on the Universe, this theory seems almost, but not quite reasonable. First, the Big Bang is essentially targeted at two fundamental and hereto unexplained features of the Universe; 1) that it is expanding and 2) that there seems to be no other reasonable explanation of its origins. Beyond these two conditions, which the Big Bang seems particularly well suited to explain, are other observations that it doesn’t address quite so elegantly. One of the biggest problems with the Big Bang is the distribution of matter. Deep space astronomy has revealed that there is a remarkably even...

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...