Ultimate Questions About the Universe

I was watching a program about String Theory on Nova the other night, and it made me think about my views on it. It is the present attempt to bring all of physics together into a unified theory, and it still has some serious problems. I'll get to them later, but first let's look at where the real problems in relation to the universe are. As you would expect, they are with the very largest things in the universe (or, in essence, the universe itself) and the smallest things.
     The largest things center on the overall structure of the universe and its beginning. the biggest problem here is the immensity of the universe. Where does it end? How big is it? And there's the age old problem that if you say that you have determined where it ends, someone is always going to ask what is on the other side of the "end." Einstein solved this problem to some degree by showing that space is curved (by the matter in it) and therefore it has no end. It would be great if this was all there was to it, but we know the universe is also expanding -- all the galaxies are moving away from one another -- so the universe is also getting bigger. But what is it expanding into -- empty space? This, of course, doesn't make any sense. The answer is that its the space between the galaxies that is expanding, and the galaxies themselves are not expanding.
     This still doesn't answer the question: Where is the end of the universe? Does it go on forever? What, in fact, does "forever" mean?
     One answer is that because of the finite speed of light, as we look out into the universe we are looking back in time. We therefore do not see distant galaxies are they are now; we see them as they were many years ago, and the further you look out, the "younger" they appear. And since we have considerable evidence that the explosion that created the universe took place at a specific time -- namely, about 20 billion years ago (there's still lots of controversy about its true age). This means that if you look 20 billion years back in time you will see the "beginning," or in essence, the  Big Bang. And since nothing existed before this time, we will see "nothing" past it. So far, it doesn't seem like we are "seeing" this point in the universe, even with our largest telescopes.
     What does this mean? We're not sure, but it is obvious that there's still a lot we don't know about the universe. And we certainly don't have a theory that explains everything, and somehow I'm a little leery about whether we will ever discover a real, ultimate, theory of everything.
     Anyway, let's turn to the other end of the scale, namely, to the smallest things in the universe, and it's pretty obvious we have an equally serious problem here. There's no doubt that we have learned a tremendous amount in the last few years, but we still haven't answered the question: What is the "ultimate" building block of the universe? In other words, what is the smallest unit that is not composed of some other kind of sub-particle? At one time we thought atoms were the smallest unit, then we discovered they were made up of electrons, protons and neutrons. Then things got even more complicated: we discovered that protons and neutrons were made up of quarks. This was a good discovery, however, because it made things a lot simpler. So many new particles were being discovered that scientists had no idea how they "fit together" or were related. Things didn't make a lot of sense. Quarks changed this, and made a lot more sense of things.
     But there was another problem: most particles interacted. In other words, there were forces between them. Then physicists noticed that these forces were actually due to the exchange of particles between particles, and this gave us a few new particles which we called gluons, photons and gravitons. And again we have a problem that is similar to the one we mentioned about the universe,namely, when you have any type of particle you can always ask what it is composed of. We do, however, have something that helps here; it's called the "Uncertainty Principle." It tells us that as we go to smaller and smaller distances we eventually reach a region that is "fuzzy." In a sense, everything goes out of focus and we can see no further.
    Let's go back to String Theory now. It assumes the basic unit of the universe is a tiny, tiny string that forms a loop. These strings are billions of times smaller than the smallest particles we can see, or even test indirectly. And the problem with this is that we are dealing with things on such a small scale when we talk about strings, we will never be able to test the theory. It's out of our range, and always will be. And therefore there's nothing we can ever do to prove t right or wrong. We have to ask therefore if it's really a "theory" in the usual sense, or is it just a "philosophy." It is, indeed an very elegant piece of mathematics, but does elegance make it right?  I don't think so