Wednesday, September 29, 2004

The ghosts of physics

Newton – Coulomb – Faraday – Maxwell – Einstein – Q.M.

Ever since the heydays of relativity and quantum mechanics, we’ve been told to leave our common sense behind and get with it, and ever since then physics has been getting weirder and weirder. Although we shouldn’t be surprised, for when we evolved as a distinct branch of the primates, the appeal to our imagination was a necessary evil for the whole species to continue its evolution and bring about a long-term project called civilization. In spite of the beating-on-the-chest incantation by some members of our species that nature never promised to reveal its inner workings or that reality simply lies beyond our capabilities of understanding, nevertheless we have let our imagination soar to unbelievable heights just to prove these people wrong. In particular, physicists have undergone the grand project of laying down the blueprints that would accomplish just that: unravel the secrets of the universe. Even as distressful as quantum mechanics, which puts limits to our understanding, we nevertheless pulled our sleeves up and told ourselves, “Let’s get with it.” And soon we found ourselves talking about quantum teleportation, time traveling, alternate worlds, and a universe of ten, eleven or perhaps fifteen dimensions, depending on the weather of the day. I shred to think of what kind of frenzy the whole planet will throw itself into if dark matter or dark energy is ever discovered, after all, according to the latest calculations, 97 % of the universe swims into this exotic soup. We, of the ordinary-matter complexity on the other hand, only make up the feeble remaining 3 percent. On the downside, what a demotion since the times we believed we were right at the center of the universe. Are we getting, in a twisted way, what we deserve for our stubborn attempt to unravel the nature of reality? The cruel irony might turn up to be even crueler than we can imagine! Now, I’m not trying to diminish the accomplishments of physics, which are well known and would take a whole encyclopedia to enumerate them all. But throughout the ages, physics, in its dealings with Nature, had a way to fumble into an impasse. I will try to point out to the peculiar nature of how our brilliant minds pulled us from the quagmire, which in most cases, resulted in dragging us over into even more fragile territory.

Nietzsche had pointed out that to engage in any inquiry, we must inevitably be selective. In some arbitrary way, we assign a greater relative importance to some things, and still others we completely ignored. We do not, cannot, begin or end with all the data. Moreover, in particular in mathematics and to some extent in physics also, we begin with undefined elements, such as a point or a line. I shall refer to these things as black boxes, since we do not concern ourselves with the inner workings of these things. It’s pointless to ask ourselves what is a ‘point’ or a ‘line’ made of? I will also refer to these ‘black boxes’ as ‘ghosts’ for no more reason that the notion of a ghost carries a distinct appeal to the whimsical nature of our imagination.

Historically speaking, the first culprit – read: a brilliant mind who took us out of a quagmire into even more fragile territory – was Isaac Newton with his universal law of gravity. Now by today’s standard, this is a trivial matter, but we seem to forget into what kind of a mess Sir Newton brought us. Until then, we all knew that a force was transmitted through matter. I push on a wall, you pull on a rope. Horses used to pull carts ‘not at a distance’ but through the intermediary of ropes, knots and pulleys. And, have you ever try to row a boat in ‘empty space’? The insanity to propose that a force, gravity, could act at a distance through empty space was just that: insane. Or rather spooky. Hence, the notion of ‘black box’, or ‘ghost’ as I said earlier as a preferred choice of word. Nonetheless, this was a major departure from our common-sense ideas. Still, we had to get on with things, and we reassured ourselves that the bottle with the genie was well secured.

In Science Fiction, we are told that you are allowed one lie. If only physics had applied this timeless truth. In those days we knew certain phenomenon that fell into the category of like things repel and unlike things attract. So we came up with another black box called a ‘charge’. Ever wonder what is a charge made of? If the electron is the smallest entity that carries a unit of charge, why doesn’t it tear itself apart? What’s a quark doing with carrying one-third of that charge as if carrying some loosed change? But I digress. From a historical perspective, after Newton, here comes along Coulomb certifying the existence of the electric force, i.e. a ghost acting at a distance, because certain things had a charge, another eerie thing with a ghost-like nature. As if the nightmare wasn’t over, Faraday confounded our imagination by defining the electric field at a point in space as the force per unit charge. Notice: point = ghost, force = ghost and charge = ghost, therefore electric field = ghost to the third power. This will have grave consequences in the centuries to come. However, all was not desperate, we went on with things, and since we are copycats, we resorted to the same dubious, brilliant tricks in defining the magnetic field, another cubic ghost.

In the meantime, we enjoyed a wonderful time with such things as energy, entropy, sound and light. In fact we could devise the whole universe as being divided as energy transport either by particles or by waves. Another trivial thing to remind ourselves is the working of a wave. Just like force, we need matter, referred here as the medium, to transfer a wave. You tie one end of a rope to a wall, give it a kink on the other end, and the kink will travel through the rope, hit the wall, and bounce back. Water waves are even more fun, since you can surf on them. And sound can’t bring music to your ears without the presence of air molecules or some other medium. After Newton’s historical first tragedy, compounded over the years into the cubic ghosts of the electric and magnetic fields, there came the second historical tragedy with Maxwell, tragedy because of the brilliance of the man. The image is impinged on my mind forever. An oscillating electric field and, perpendicular to it, an oscillating magnetic field, the whole thing propagating at the speed of light like a train forever moving in search of the Holy Grail. In one stroke of genius, Maxwell tied up three branches of physics, namely electricity, magnetism and light, which later would make Einstein die of envy in trying to link these with gravity in his grand unified theory. It is so brilliant that one can forgive Maxwell for using in the first place cubic ghosts in his design. In fact, we were ready to live with that. Except for the Michaelson-Morley (M&M) experiment, which had the single effect of throwing a monkey wrench into the grand scheme. Well, if electromagnetic waves, as those ghostly creatures came to be known, which Marconi was going to demonstrate eventually, can travel from antenna to antenna, they should be propagating in some medium. After all, if there are made of waves, they can only travel in a medium. But the M&M experiment was going to deny us that last grip on reality. If they are wavering like water waves, there is no water; if they are kinks on a rope there is no rope; if they are air molecules transmitting sound, there are no air molecules! The electromagnetic waves simply whizzed by at the comfortable speed of light in pure, empty space, the electric field and its twin, the magnetic field, two ghosts oscillating in perfect harmony to give you the jitterbug. Or I should say the jitterbug to the electron, the one carrying the ghostly charge. But what is carrying this wiggling? Is space really empty? Does this question have anything to do with dark matter and dark energy, that ninety-seven percent part of the universe that refuses to give us any evidence it really exists? One thing is sure is that ‘empty’ space doesn’t mean ‘empty’ of properties, which definitely qualifies it as a ghost. Reviewing Faraday’s definition of the electric field, that makes it a ghost to the fourth power, or in physics parlance, a 4-dimensional ghost. Ditto for the magnetic field. And our electromagnetic wave is a lot more complicated that we had originally anticipated, and Maxwell can put the blame squarely on Newton, the original culprit who led us down the path of the spooky garden.

Of course, we really needed a brilliant, brilliant mind to lead us out of this horrendous quagmire into… even more fragile, horrendous territory. And yes, as you may have guessed, I’m talking about the one and only Albert Einstein, who doesn’t need any introduction. There are people when they see a good thing just know how to take advantage of it. Put Einstein on that list. His original idea can be simply stated as such: if anyone is going to be spooked out of his mind, and since the universe plays no favorite, then, no matter what inertial frame of reference, every other observer will be spooked equally. Actually this was a very noble attempt to put every one on an equal footing. The dreadfulness of this is that it had dire consequences. For one, there is an absolute speed that can’t be surpassed, the speed of light, which ever since has given headaches to science fiction writers. Second, time will slow down for anyone who wants a quick thrill by moving faster and faster, closing in on the speed of light. Therefore, time = ghost. At the same time, your body’s extension in the direction of motion will contract. There’s actually a debate as to whether your body contracts or is it space itself that really contracts, but the subtlety of this debate indisputably escapes me. Nevertheless that would make, according to our calculation, space = ghost to the second power, raising our electric field to the status of a 5-D ghost. Now we won’t delve into what Einstein did to gravity – it is well beyond the scope of this article – but suffice to say that he showed us that empty space is curved, an extraordinary feat of adding another ghostly dimension to it. And so our innocent electric field has transmogrified into a monstrous 6-D ghost.

And to be frank with you, in my student days, I was willing to live with this monster. I was willing to cozy up to it. I was even willing to sleep with the beast. Hey, after all, it gave us, physics students, an air of sophistication, and that was cool. No matter how hard to imagine this, nothing so far had prepared us for what was coming next. Now Quantum Mechanic is not only the flagship of physics but it is also the crown jewel of all science. In its claims, it is unsurpassed and unrivalled. It is the basis to explain the Periodic Table, the foundation of all chemistry and biology. It is the basis of solid-state physics, plasma physics and astrophysics. It can explain the specific heat of materials, the conductivity of conductors, insulators and semi-conductors, the basis of all electronics, TV sets and computers. It is the basis to explain the composition of stars, their birth, evolution and death. To enumerate all of its accomplishments would require a book the thickness of a New York’s phonebook. And yet, the fundamental idea of Q.M. is so simple that even a child can easily grasp it. Energy comes in bundles, like currency. If the penny is the lowest value in a currency, all other denominations are multiple of it. A nickel is five times that, a dime, ten times, a dollar, a hundred times, etc. You can’t pay a bill of a penny and a half or three-quarters of a dime. You have to round off the amount to the nearest penny, which will then become an integral multiple of a penny. Likewise, at the microscopic level, the level of atoms, energy is transferred only in bundles of a fundamental quantity called the Planck’s constant, in honor of the scientist who discovered it in 1900 when physics had finally caught up to the world of finance. However, once you accept this simple idea, then things get complicated. A consequence of Q.M., namely Heisenberg’s Uncertainty Principle, puts an undesirable damper on the grand scheme of unraveling the secrets of the universe. Also, there is nothing you can devise (i.e., come up with a different theory) to circumscribe the Uncertainty Principle. In the world of physics, this is known as the Copenhagen Interpretation, as it was proposed by Niels Bohr who did most of his research in that city. But this had the effect of sending shivers down the spines of great men, such as Albert Einstein who couldn’t accept Q.M.’s final verdict with his famous saying: ‘God doesn’t play dice with the universe’. He tried for long years to discredit its interpretations, and after his death, legions of physicists have carried his torch. We shall not explore this traditional debate that took place throughout the twentieth century. Suffice to say that, so far, this is the score: Q.M. a dozen or so points; opponents, a big fat zero.

Now the fact that our 6-d ghostly electric field turns out to be tied up to Q.M. can be considered as one of those freaky accidents of nature. It was definitely not the original intentions of the fathers of Q.M., who had no idea in those days that the electrical field was a 6-d ghostly creature. Until this disclosure, the electric field was considered as real as the mass of an electron, or the momentum of a bullet, or the Earth’s orbit around the Sun, etc. If you send an electromagnetic field and an electron feels its presence somewhere down the line, it will react. Hence, to the electron, this 6-d ghost is real, no question about it. The same thing if you jump out the window, you will crash on the ground. Don’t try it unless you’re wearing a parachute. The thing is that falling down is not spooky, but it demands an explanation. And gravity is a concept, albeit the best concept we have come up so far to explain this phenomenon but its definition has spooky elements in it. And so has the electric field. Now prior to Q.M., a wave was thought to describe real things, such as amplitude, wavelength, frequency, and velocity. Similarly, the electromagnetic waves, made up of an oscillating electric field and an oscillating magnetic field, in Maxwell’s equations were thought to represent something real, something an electron would answer to. But in Q.M., this same electric field turns out to represent a probability wave, one that tells you on the odds that a photon, i.e. a bundle of energy, is present in a given volume of space. The wave in Q.M. no longer represents anything real. In fact you have to make a measurement so that this probability wave will ‘collapse’ into something real that can be observed, often called an observable. The 6-dimensional ghost that has become a probability wave contains all the information that one can ever hope to extract about such a thing as an electron. It’s as if the electron has an identity crisis. It exists in the spectrum of all possibilities until you perform a measurement, and that’s when the observable under scrutiny will take on a specific value. In other words, in line with what is suggested here, Mother Nature needs your intervention to make the ghost collapse into a real thing! And only then will it appear as real! Now, if that hasn’t spooked you out, nothing ever will. Nevertheless, even though I am a skeptic, the amazing thing is that Q.M. really works. And as we have seen so far, and in fairness to Q.M., the physics prior to it, also called classical physics, was really built on ghosts, namely the 6-d ghostly electric field. That this turns out to play a crucial role in making Q.M. spooky should not surprise us anymore. After all, we get what we deserve. We were fooling around with ghosts, we should have expected at some point to be spooked out. Is it any wonder that physics ever since Newton has gotten weirder and weirder?

Time – Galileo – a universe of matter, space and motion – why you will never travel back in time to kill Hitler’s grandfather - the Big-Bang Theory.

It was precisely the law of inertia, which Galileo cleverly discovered, that set up physics on the right course to follow. Now lets take a second look at what was done then. Galileo had concluded from his slope experiments that if a body is set in constant motion along a straight line it will keep on moving constantly along that straight line, unless an unbalanced force compels it to do otherwise. How radical was that? Remember, until then, people believed that to keep on moving, one needed a force. Rowing a boat and pulling a cart with a horse were two examples everyone was familiar with. Galileo was stating something entirely different. If something stops moving, speeds up, or deviates from a straight line, it means that an unbalanced force is at play.

But more importantly, for this discussion, how do we know that this body is moving in a straight line with constant motion? It’s the part with the constant motion that I want to focus on. Now, deny this law and the whole of physics tumbles down. It is the cornerstone for both Newton and Einstein. So we are treading on dicey waters. When I do measure the velocity of a body, to determine whether it is constant or not, what is it that I am really doing? I need a clock, a measuring tape or ruler, and a body, or more precisely a body moving in space. But so is the ticking part of the clock, which is a body moving in space, without which I don’t have a clock. So basically, I’m comparing the motion of a body, the observed one, to the regular moving part inside the mechanism of the clock. In all this, to make quite sure that the body under observation is moving with constant velocity, and not cheating on us, the regular or cyclical motion of the moving parts of the clock must be, well, regular or cyclical. But how do I know this? The thing is I have to measure all my clocks against a standard, to make sure that they also don’t cheat on me. But against what do I measure the standard? There was a time that a second was defined as a fraction of a day. The main difficulty with this is that there is no guarantee that the Earth will take exactly the same time to complete a full revolution, say for the next five billion years. So now we define a second as 9,192,631,770 oscillations of the cesium atom. But that begs the question, are all nine billions plus oscillations equal at all times, under any given condition and how would I know this? The only thing that can be said is that this definition might be slightly better than the previous one, and one must make a leap of faith at this point. Regardless, suppose I have convinced myself that the ticking part of the clock is standardized. Still, determining whether or not the observed body is moving in a straight line with constant velocity means that I am comparing its motion with the motion of the ticking part of the clock. To declare that it is moving with constant velocity it is to declare that for every regular motion inside the clock, the tick, the body moves a constant distance, which can be measured with a ruler. I am making a one-to-one correspondence between the motion of the observed body to the motion of the ticking part of the clock, being itself regular or cyclical. And how de we define regular or cyclical? But whatever, on that ground, I can declare whether or not an unbalanced force is exerted on the observed body. As you can see the difficulty, and if we add on the difficulty of defining a straight line, one can only conclude that this is indeed a thought experiment, albeit a very important one.

Now, had we known from the beginning that when we were observing the motion of a body, or trying to measure it, we were actually comparing its motion to the moving part inside of a clock, it shouldn’t have come as a surprise when Einstein demonstrated that time is relative to the motion of the observer. Time is a by-product of matter moving in space, and motion is relative. Let us consider measuring the motion of a body with respect to a clock. In so many ticks, the body has moved from point A to point B. What I am basically doing is linking the motion of the body with the moving-part mechanism inside the clock, i.e. the ticking part of the clock. And what is that ticking part of the clock? Think of a pendulum clock, a water clock, an hourglass, or even the most sophisticated modern clock with its atomic motion. In all clocks, it is some matter moving in a regular, cyclic way. While this is no surprise, the implications are deep. Calling the moving process inside the clock, time, does not create some exotic reality in which it is possible to go back and forth (like in time traveling). Moving back the object from point B to point A accomplishes just that and nothing else. That is the very reason why motion must be given a direction so that we are not confused about what is happening. Historically speaking, people used the notion of time when in fact they were unwittingly referring to some celestial motion. It was due to our forefathers’ lack of knowledge in that area that led us astray. In an era when some believed that the Earth was flat and one could fall at the edge, a day, defined as sunrise to sunrise, or by any other variation, actually referred to one complete rotation of our planet on its own axis. Even today, it is much more convenient to say, ‘I’ll meet you in an hour’ rather than ‘I’ll meet you when the Earth has completed 1/24th of its rotation from now’. A year was observed through its regular cycle of spring, summer, fall and winter, along with the regular motion of some of the patterns of stars, which we ingenuously called constellations. It took thousands of years to understand that this was the result of the Earth orbiting around the sun. Even today, it is much more convenient to say that my doctor’s appointment is in a month, rather than in 1/12th of the Earth’s orbit around the sun. That 1/12th of the Earth’s orbit around the sun isn’t exactly one month is beside the point.

The point being made is this: what do I need to create a universe? For one, I need matter, hopefully of different flavors. A universe made solely of protons would be kind of ugly, if not useless. But add electrons to the mix and we get the chemistry of life. Also, we need different types of interactions: the gluon force to make different nuclei, the electromagnetic force to form different atoms and molecules, gravity to collect huge conglomerates of matter into solar systems. We also need motion for our chunks of matter, if we ever hope that they will interact, and space, if they are going to move from point A to point B. Although this picture is simplistic, nevertheless, we have the necessary ingredients to make a universe, that is, matter and its diverse interactions, motion and space. Hum, I did leave out time. Huh, I wonder why! Time is a by-product. It is the result of matter moving in space. To produce a clock, one needs the requirement that the motion of a chunk of matter be regular or cyclical. Only a conscious mind can do that. Monkeys and dolphins, although smart in their own ways, and maybe self-aware of their own individuality, are incapable to hold the very notion of time in their heads. An ancient philosopher once described time as a river flowing. Here, again, the analogy adequately uses chunks of matter moving in space, though with this analogy some people might get the idea that going against the current is tantamount to moving back in time. No such luck, all you would be accomplishing is reverse course in space. Remember that the universe does not deal with time but with matter in motion. In a universe without motion, if this were possible, time would not exist. Only humans can deal with the notion of time as described here -time is in a one-to-one correspondence with the regular cyclical motion of the moving parts of a clock - and we do it in order to make a worthwhile attempt to understand the complexities of our universe. But time traveling, although a fascinating subject, is a human fantasy. That’s why you will never go back in time to kill Hitler’s grandfather. However, to kill time, you can always speculate on it! And so this spells big problems for the Big-Bang Theory (BBT) since it goes over to discuss what happens to the universe when t=0. In any graph one shows two variables in one-to-one correspondence. The choice for one of those variables to be zero, in this case t=0, is an arbitrary choice. What the proponents of the BBT have done inadvertently is give an absolute character to t=0, which is an inconsistency. Recall that time itself is in a one-to-one correspondence with the regular cyclical motion of the moving parts of a clock. Its value, t=0, is completely arbitrary. Therefore the BBT would have to qualify as the weirdest of all the weird theories the human mind has produced so far.