Tuesday, September 16, 2014


Is Our World a "Fluke" of Nature?
One of the most important scientific questions that we have not yet answered is : Why are we here? Or of even more importance: how did we get here? And, indeed, if you delve very deeply into the question you soon find that the odds against us being here are incredibly large. One of the major things that showed us this is known as the anthropic principle. It was put forward by Brandon Carter in 1973, and it has continued to cause controversy and confusion amongst physicists and astronomers ever since. It is simply stated as: If the fundamental constants of the universe were different – even by an infinitesimal amount – we would not be here. The earth might exist (or it might not), but it wouldn’t support life as we know it.

What do we mean by fundamental constant? It turns out that our universe has several of them and they include the mass and charge of the electron, the gravitational force (referred to as G), and various ratios between them.

A few of the questions we cannot answer are: Why is the mass of the proton exactly 1,835.153 times the mass of the electron? Furthermore, why is the mass of the electron what it is? In addition, there is the charge of the electron; it’s exactly equal, but opposite to the charge of the proton. Why does it have this charge? And inside protons are particles called quarks. Why do they have charges of 1/3 and 2/3 that of the electron? And why is the gravitational constant exactly equal to 6.6738 ´ 10 ̄ ¹¹?

We can’t answer these questions, but what is more important is that the anthropic principle says that if they were different – even by an infinitesimal amount – life would not exist on Earth. Life, in effect, is tuned to them. At the present time we have no idea why this is true. A number of well-known physicists, however, have speculated that when we finally get a " Theory of Everything" we will know the answer. Some have suggested that all we really need is a quantum theory of gravity (at least it would be a first step). But things look pretty bleak at the present time that we’ll achieve such a theory. Most of the work in this direction at the present time is going towards what is called " String Theory." According to this theory the universe consists of many more dimensions than the usual four that we observe – possibly 10 or 11. And these extra dimensions are curled up so we can’t observe them. The biggest problem with string theory, however, is that, unlike most theories, it doesn’t make predictions that we can check. In addition, the strings themselves are so tiny we’ll never be able to observe them.

So there appears to be a quandary. The anthropic principle seems to show us that life on Earth is a fluke of nature; in short, it predicts that only one in hundreds of trillions of stars have a planet that could support intelligent life. This appears to indicate that we are the only planet that contains intelligent in our galaxy. Furthermore, we know that reserves on our planet will only allow us to exist for a few thousand years more (with luck maybe a little more) then there will be no intelligent life in our galaxy.

But for years we have assumed (and it appears to be true) that if the conditions are just right on a planet of the right size in regard to temperature, proper atmosphere, proper energy sources and so on, that life (and even intelligent life) should arise. Furthermore, in recent years we have discovered a large number of planets in our neighborhood of space, and some have relatively ideal conditions for life (not as good as Earth, but reasonable). What does this mean?

Monday, March 24, 2014

An Amazing New Discovery -- We Hope

It might seem strange that a number of fundamental ideas, or theories, about the universe have been around for many years, but still haven't been proved beyond a doubt. One of the major ones is the Big Bang theory, in other words the idea that the universe began as an explosion 13.8 billion years ago -- in particular, that it began as a tiny point that expanded very rapidly. Another fundamental prediction is that the universe is filled with gravitational waves -- waves that are emitted when matter is accelerated. It was predicted by Einstein many years ago. And in the 1980's an inflationary version of the Big Bang theory was put forward. It assumed that in the very early stages of its expansion the universe exceeded the speed of light.
     A team of researchers headed by John Kovac of the Harvard=Smithsonian Center for Astrophysics has recently made a discovery that could prove that all three of these ideas are indeed valid. Their experiment was set up at the south pole, and it consists of an instrument for measuring minute distortions in the cosmic background radiation that permeates the universe. And indeed they have found a small ripple that may have been produced in the early stages of inflation shortly after the Big bang began. If it is verified it will be a momentous discovery, and indeed several teams are now trying to repeat it.

Wednesday, August 1, 2012

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

Friday, July 20, 2012

Why is There So Much Excitement About the "God Particle"?

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.

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.

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.

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.