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.
Friday, July 20, 2012
Tuesday, July 10, 2012
The Overwhelming Probability of Life Elsewhere in the Universe
One of the greatest mysteries of the universe is whether or not there is life -- in particular, advanced forms such as ours -- elsewhere in the universe. The discovery of another planet with an advanced civilization on it would be the greatest discovery ever made on Earth. It would, in fact, be difficult to imagine what its consequences would be. This may not happen in the next few years but there's no doubt that it will eventually happen. (It will be difficult for us to communicate with them because of the tremendous distances involved.) The reason we are so sure of this comes from the data that the spacecraft Kepler has collected and is still collecting. It's object is to find Earth-sized planets around some of the nearby stars and determine as accurately as possible how many of the billions of stars in our galaxy may have Earth-like planets. And it has succeeded beyond our wildest dreams. As of January, 2012, it has discovered 2326 candidates, with 207 of them are similar to Earth in size.(There's no doubt that this is a monumental discovery.)
For life to arise on a planet we not only need a planet similar in size to Earth (mostly because of problems with gravity) but we also need the planet to be in the ecosphere or life-zone of the star. In addition, the star should be similar to our Sun. Of the 207 Earth-like planets discovered, 48 appear to be in the life-zone of their star.
It's important that the planet be in the life-zone because water would be in a liquid state most of the time in this zone -- and this is critical. There's no doubt that life needs water to survive. but would life form naturally if water was there? If there was an atmosphere composed of the proper chemicals it would (methane and ammonia would be needed, but they are very common). Scientists showed many years ago that with the proper atmosphere, proper temperatures and liquid water, a very elementary form of life would evolve naturally. From there it would no doubt evolve to a higher form of life. It would take a long time -- millions of years -- but there's no doubt that it would occur. After all, the universe has been around for billions of years.
With only 48 good candidates, you might think that the probability of it occurring in them is pretty low -- and indeed it is. But with the data that the Kepler team has, they have been able to show statistically that 5.4 % of all stars in our galaxy have Earth-sized planets. Furthermore, they showed that 17% of all stars have many planets orbiting them. And with over 200 billion stars in our galaxy that gives a lot of Earth-sized planets -- about 10 billion. For most people, 10 billion is hard to visualize so I'll give you a simple picture. It's about equal to all the grains of sand in all the beaches on Earth. I think that should convince you that it's a lot.
If only a tiny fraction of these planets -- say, one in hundreds of thousands -- had a planet similar to Earth -- we'd still have millions of planets out there like us.
And this isn't the end of it. So far I've only talked about our galaxy -- the Milky Way. It is only one of billions of galaxies in the overall universe. There are, in fact, galaxies as far as we can see, and we know we're not seeing the end of the universe. We may only be seeing a small fraction of it. So, needless to say, it's a big place with an incredible number of planets similar to Earth. On the basis of this, what's the chance we are the only advanced civilization in the universe? I would say it is zero, or very close to it. As hard as it may be to believe, there has to be millions (and possibly many more) of civilizations in the out there similar to us.
For life to arise on a planet we not only need a planet similar in size to Earth (mostly because of problems with gravity) but we also need the planet to be in the ecosphere or life-zone of the star. In addition, the star should be similar to our Sun. Of the 207 Earth-like planets discovered, 48 appear to be in the life-zone of their star.
It's important that the planet be in the life-zone because water would be in a liquid state most of the time in this zone -- and this is critical. There's no doubt that life needs water to survive. but would life form naturally if water was there? If there was an atmosphere composed of the proper chemicals it would (methane and ammonia would be needed, but they are very common). Scientists showed many years ago that with the proper atmosphere, proper temperatures and liquid water, a very elementary form of life would evolve naturally. From there it would no doubt evolve to a higher form of life. It would take a long time -- millions of years -- but there's no doubt that it would occur. After all, the universe has been around for billions of years.
With only 48 good candidates, you might think that the probability of it occurring in them is pretty low -- and indeed it is. But with the data that the Kepler team has, they have been able to show statistically that 5.4 % of all stars in our galaxy have Earth-sized planets. Furthermore, they showed that 17% of all stars have many planets orbiting them. And with over 200 billion stars in our galaxy that gives a lot of Earth-sized planets -- about 10 billion. For most people, 10 billion is hard to visualize so I'll give you a simple picture. It's about equal to all the grains of sand in all the beaches on Earth. I think that should convince you that it's a lot.
If only a tiny fraction of these planets -- say, one in hundreds of thousands -- had a planet similar to Earth -- we'd still have millions of planets out there like us.
And this isn't the end of it. So far I've only talked about our galaxy -- the Milky Way. It is only one of billions of galaxies in the overall universe. There are, in fact, galaxies as far as we can see, and we know we're not seeing the end of the universe. We may only be seeing a small fraction of it. So, needless to say, it's a big place with an incredible number of planets similar to Earth. On the basis of this, what's the chance we are the only advanced civilization in the universe? I would say it is zero, or very close to it. As hard as it may be to believe, there has to be millions (and possibly many more) of civilizations in the out there similar to us.
Monday, July 9, 2012
The Exercise "Miracle"
There are numerous benefits of exercise, but there's one that is so great that it can only be classified as a "miracle." Exercise breaks down cells in your body, which may seem like a bad thing, but it's not (it's actually a great thing). Your body clears out the broken down cells, and builds new one. And if you exercise, it senses that your muscles need to be be rebuilt stronger, and it makes them stronger. Exercise is therefore one of the best ways to build and maintain a stronger and healthier body.
It may seem strange, but your immune system is at the forefront in this change. You no doubt thought that your immune system's main job was to protect you from disease, and indeed it does, but it's also involved in muscle building. So let's begin by looking at your immune system. I'll try not to get too technical. It actually consists of two systems, referred to as the innate system and the adaptive system. The innate system gives the first line of defense against foreign invaders such as bacteria, viruses and so on. When it detects a foreign particle it swings into action, triggering inflammation that walls off the invaders. The adaptive system is a backup system. If the innate system fails to contain the invaders, it comes into play. It calls up white blood cells called B and T cells to attack the foreign particles. And one of the most amazing things about the B cells is that they have a memory. After the invaders have been overcome, they study them and learn how to deal with them the next time they invade. They're now ready for them; they know what they look like and can attack them immediately.
But let's go back to the innate system again. The two major particles of this system are called macrophages and dendritic cells. They secret tiny proteins call cytokines which play a vital role in the immune system. They are "messengers" that direct and oversee most of what goes on.
So how does all this relate to building better muscles? The answer is that exercise and body building stretches and tears muscle cells, breaking them down. They die and have to be replaced, and it's the cytokines that direct and control the reconstruction process. There are actually several types of cytokines; one of the largest group is known as interleukins.
Okay, let's go back and see exactly what happens when you exercise. With the accumulation of dead cells, one type of cytokines, called inflammation cytokines call in white blood cells to begin the demolition. During this stage the old cells are cleared out and everything is readied for the next stage. In this next stage another type of cytokine called growth cytokines go to work. They make the new muscle cells bigger and more powerful than the ones they are replacing. I'm assuming, of course, that your muscles were exercised relatively hard before all this began. How hard does this exercise have to be? I think it's safe to say that it has to make you huff and puff a little. In essence, you have to challenge your muscles. If you don't, your old, dead cells will be cleared out, but your new cells won't be build bigger and stronger.
So it's easy to see why exercise is so impotant.
It may seem strange, but your immune system is at the forefront in this change. You no doubt thought that your immune system's main job was to protect you from disease, and indeed it does, but it's also involved in muscle building. So let's begin by looking at your immune system. I'll try not to get too technical. It actually consists of two systems, referred to as the innate system and the adaptive system. The innate system gives the first line of defense against foreign invaders such as bacteria, viruses and so on. When it detects a foreign particle it swings into action, triggering inflammation that walls off the invaders. The adaptive system is a backup system. If the innate system fails to contain the invaders, it comes into play. It calls up white blood cells called B and T cells to attack the foreign particles. And one of the most amazing things about the B cells is that they have a memory. After the invaders have been overcome, they study them and learn how to deal with them the next time they invade. They're now ready for them; they know what they look like and can attack them immediately.
But let's go back to the innate system again. The two major particles of this system are called macrophages and dendritic cells. They secret tiny proteins call cytokines which play a vital role in the immune system. They are "messengers" that direct and oversee most of what goes on.
So how does all this relate to building better muscles? The answer is that exercise and body building stretches and tears muscle cells, breaking them down. They die and have to be replaced, and it's the cytokines that direct and control the reconstruction process. There are actually several types of cytokines; one of the largest group is known as interleukins.
Okay, let's go back and see exactly what happens when you exercise. With the accumulation of dead cells, one type of cytokines, called inflammation cytokines call in white blood cells to begin the demolition. During this stage the old cells are cleared out and everything is readied for the next stage. In this next stage another type of cytokine called growth cytokines go to work. They make the new muscle cells bigger and more powerful than the ones they are replacing. I'm assuming, of course, that your muscles were exercised relatively hard before all this began. How hard does this exercise have to be? I think it's safe to say that it has to make you huff and puff a little. In essence, you have to challenge your muscles. If you don't, your old, dead cells will be cleared out, but your new cells won't be build bigger and stronger.
So it's easy to see why exercise is so impotant.
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