With the recent announcement that the "God particle" (which physicists refer to as the Higgs particle) has been discovered, people around the world have wondered what is going on. Scientist say it's a tremendous discovery. So, how important is it? It appears to be a significant breakthrough, but there's no doubt the discovery will be difficult for the average person to comprehend, and it's not likely to have any serious effect on their life (like the discovery of a new vaccine for cancer). But it is important in our understanding of the universe. Let's look at why this is so.
It's best to start with what we know about the universe. Basically, it consists of particles -- electrons, protons, neutrons and so on -- that are held together by various forces. There are, in fact, four of these forces, and you're likely familiar with at least three of them. They are: the gravitational force, the electromagnetic force, the strong nuclear force and the weak nuclear force. The gravitational force holds material bodies such as yours and the Earth together; in other words it stops you from flying off into space. And it also holds the moon in orbit around the Earth. In the same way, the electromagnetic force holds atoms together -- it holds the electrons in orbit around the nucleus. Without it, all atoms would fly apart and we wouldn't be around.
The third of the forces is the strong nuclear force. It holds the particles of the nucleus, namely protons and neutrons, together. This brings us to the fourth force, the weak nuclear force, and it's likely the one you are most unfamiliar with. Furthermore, it's more difficult to explain. The best way to do this is say that it is the force that is responsible for radioactive decay, but it also plays an important role in the universe in relation to such things as supernova explosions.
In addition to the four forces of nature we have dozens of particles, and it's the combination of particles and forces that makes the world, and the universe, go around. They are, in fact, the two basic components of it. If you can explain everything about them you know everything about the universe. I won't try to describe all the particles in detail as there are too many. Some of the major ones, however, are: electrons, protons, neutrons, quarks and photons. What physicists want to know is how all these particles and forces fit together. They would like a theory that would explain everything, and this theory would, of course, have to explain both the tiniest things in the universe and the largest (such as the overall structure of the universe).
There is, unfortunately, a serious problem at the present time. We have an excellent theory of the tiniest objects in the universe (and how they interact); it's called quantum mechanics. And we have an excellent theory of the very large things in the universe; it's called general relativity. The problem is that the two theories have almost nothing in common. Scientists would prefer a theory -- one simple theory -- that covered everything from the very smallest to the largest: a theory of everything.
So far, the best they have been able to do is what is called the "Standard Model." It explains most of what is not covered by general relativity, and it does a fairly good job. In essence it covers everything except gravity. But the Standard model has problems. One of the most serious is that all the particles described by the theory have to have mass (we know they have mass -- we can measure it). Actually, there's one particle that doesn't -- it's called the photon and it's the particle of light. To get around this problem, a "special particle" was invented, and with it everything within the Standard model was great; in other words, there were no problems. The particle that gave all these other particles mass was suggested by Peter Higgs in 1964 so it was called the Higgs particle, or more exactly, the Higgs boson. So, if the Standard model was to be an acceptable model, the Higgs boson had to exist. All scientist had to do was find it. But again there was a problem. It's predicted mass was so great, there was no way with the accelerators of the day that it could be created. As time passed, however, larger and larger accelerators were build, until finally they got up to the required energy (or mass). And finally in July, 2012, Gianotti, Heuer, and Incandela of Australia (using the huge accelerator called the Large Hadron Collider at CERN) announced that they had found the elusive particle.
Is it definitely the Higgs boson? Further work will no doubt be needed to prove it, but most physicists are confident. Then, of course, we still have the even greater step: bringing gravity into the theory.
Showing posts with label A Theory of the Universe. Show all posts
Showing posts with label A Theory of the Universe. Show all posts
Friday, July 20, 2012
Tuesday, November 8, 2011
A Theory of Everything: Is it Possible?
I was watching a program on Nova (TV) the other day about the universe, and it made me think again about how vast and complex our universe really is. There seems to be no end to it -- at least we can't find an end. And even "empty space" is much more complex than we thought. It's certainly not empty and we're still not sure what all it contains in the way of "strange" particles.
Einstein showed us that space is curved by matter and that helped clear up a few problems. But it also created a few new ones. Are we ever going to be able to completely explain everything about the universe? It always seems that when we finally explain something that has puzzled us for years, the solution creates more problems. Somehow I think this will continue on indefinitely. I'm convinced, in fact, that we'll never be able to explain everything. We may come close, and things will no doubt continue to get more and more complicated, but there will always be problems left to solve. In a sense it would be a shame if we did discover a theory that explained everything. It would mean we would have no new problems to work on. Somehow I don't think we'll ever have to worry about this; I don't believe it will every happen.
Furthermore, I'm just as convinced that there is other life in the universe beyond Earth -- in fact, I'm also convinced that much of this life is advanced (as advanced as we are). We are finding large numbers of planets around nearby stars, and with 200 billion stars in our galaxy, there has to be millions and likely billions of planets out there. And beyond our galaxy there are hundreds of billions of other galaxies with just as many stars as our galaxy. The probablity that some of them have advanced life in them is overwheming. After all, all you need is the proper conditions for life to form; they include water in liquid form, a satisfactory atmosphere and moderate temperatures. If I had to guess I'd say there are millions of advanced civilizations out there somewhere. Anyway, it's interesting to think about.
Einstein showed us that space is curved by matter and that helped clear up a few problems. But it also created a few new ones. Are we ever going to be able to completely explain everything about the universe? It always seems that when we finally explain something that has puzzled us for years, the solution creates more problems. Somehow I think this will continue on indefinitely. I'm convinced, in fact, that we'll never be able to explain everything. We may come close, and things will no doubt continue to get more and more complicated, but there will always be problems left to solve. In a sense it would be a shame if we did discover a theory that explained everything. It would mean we would have no new problems to work on. Somehow I don't think we'll ever have to worry about this; I don't believe it will every happen.
Furthermore, I'm just as convinced that there is other life in the universe beyond Earth -- in fact, I'm also convinced that much of this life is advanced (as advanced as we are). We are finding large numbers of planets around nearby stars, and with 200 billion stars in our galaxy, there has to be millions and likely billions of planets out there. And beyond our galaxy there are hundreds of billions of other galaxies with just as many stars as our galaxy. The probablity that some of them have advanced life in them is overwheming. After all, all you need is the proper conditions for life to form; they include water in liquid form, a satisfactory atmosphere and moderate temperatures. If I had to guess I'd say there are millions of advanced civilizations out there somewhere. Anyway, it's interesting to think about.
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