Physical Education

For as long as I can remember being interested in anything apart from food, toys, and fresh diapers, I’ve been interested in physics. I have almost zero interest in the math involved, and will, therefore, never actually understand any of it, but I still love trying to come to grips with the concepts … and not just the current state of the Science:  the history of nearly all branches of science interests me, none more than physics.  I love to see how ideas lead to experiments, experiments to further ideas, and how the study of one tiny facet of a problem can reveal the solution to the whole.

I must admit, I especially love it when one elegant experiment, or one original thinker, can turn previously set-in-concrete ideas totally topsy-turvy! The nature of discovery and innovation are fascinating in their own right – but the reactions of hide-bound conservatives, watching their long-cherished and comfortably well-explained universe be torn to shreds by some poor, brilliant, bastard that they’d spent months or years ridiculing … well, for me, it just doesn’t get any better than that!

Copernicus. Galileo. Kepler. Einstein. Plank. These are just the easiest to remember of the rebels against orthodoxy, who eventually got to have the last laugh (some of them posthumously, it’s true.) There are tons more, in every branch of science, from Galen (“Look, I just pulled this out of a human cadaver, and It has four lobes, not five!”), to Kaluza (“Wow, if I just add some extra dimensions, I can unify all of the forces!”.)  Each was a martyr, of one sort or another, to the idiocy and arrogance of people who are so certain they know everything, that they can’t even be bothered to look at evidence to the contrary, or listen to someone who’s got a different idea …

I am not a brilliant man – but I’m different from most people, and have been an outcast most of my life, so I feel a kinship with these explorers of truth, and I sympathize with the hardships they endured, and revel in the richly-merited comeuppance their detractors eventually get!  All the more so, that, in science, unlike philosophy and theology and political ideology, it is actually possible to prove that one version is right, and the other wrong!  There’s a delightful sense of closure that comes with being able to label a bunch of closed-minded jerks as Closed-Minded Jerks, and then point to proof – measurable, reproducible proof –that even the closed-minded jerks’ followers will have no choice but to accept!

Sadly, such a thing is impossible in politics:  there can be no meeting of the minds, not really.  Closed-minded jerks in the political arena can seldom be proven to be closed-minded jerks in such a way that they loose all backing and descend into the powerless obscurity that they damned well have coming … (Joe McCarthy and Richard Nixon are among the very few exceptions I can think of.)

In Physics, examples of such upheavals are plentiful, and the comeuppance of the Closed-Minded Jerks (hereinafter referred to as CMJ’s), is especially delicious!  Take, for example, the Case of Michaelson and Morely …

In the late 19th century, the debate as to whether Light consisted of particles, or waves, had seemingly been settled in favor of the latter. Unfortunately, there was a bit of a snag:  if light was a wave, something had to be waving!  A particle can travel through empty space, but not a wave:  all waves that had ever been observed, required a medium: be it air, water, or solid rock, there had to be something to oscillate and pass the energy on. It was essential. Experiments with refraction had proven that light can do things that waves can do, but a particle simply can’t … so light was a wave, and therefore, space, through which light is known to travel, absolutely couldn’t be the completely empty vacuum that it appeared to be – it simply had to be filled with a substance that the energy of light could cause to wave!

They called it the Luminiferous Aether, and began excitedly calculating what the characteristics of this substance must be, to account for all the various light-involving phenomena that had been observed, over the centuries. The harder they worked, the more freaking impossible this stuff turned out to be – but it simply had  to be there, so damn the calculations and full speed ahead!

It’s sort of appropriate that I appropriated a nautical expression to describe their attitudes, as it was a very nautical sort of phenomenon that was going to bring the entire thing down on their heads.

The stuff was everywhere, remember, and the Newtonian physics of the time embraced the concepts of absolute time, absolute motion, and a speed of light that varied like the speed of anything else. When these were factored into the mess, theory held that the Aether, permeating the universe, must be stationary, relative to everything else out there.  Just as a fish moves through the sea, the Earth must move through the Aether, and, that being so, it should be possible to measure the exact velocity of the Earth in this aether-filled universe – and that, in turn, would tell us all sorts of cool things to base more theories on!

Measuring it should be simple:  shoot a beam of light out in the direction of Earth’s apparent motion, and another in the opposite direction, then compare how long the reflected beams took to return to source – the beam shot out ahead of Earth should get back faster, because the Earth would overtake it, while the beam shot out behind would have to travel further to catch up with the speeding earth. All that remained was to find a method for precisely measuring the speed of light.  Various people tried it, all of them using methods that were either not sensitive enough for the task, or which had some other design flaw that rendered the results worthless. Until a pair of researchers, Michaelson and Morely, at what is now Case Western Reserve University, in Cleveland, Ohio, invented a device they called an ‘interferometer’.  The design was an elegant one, using the way in which light waves out of phase with one another could cancel each other out, in order to determine with very high precision, the velocity of light.  Further, just to be safe, they carried out their measurements at various points of the Earth’s rotation, and orbit, so as to get data on the speed of light in all orientations to the hypothetical Aether …

The trouble was, the speed of light didn’t seem to change, no matter what direction it was pointed.

I can picture the two men going over their results, and looking at one another with increasing desperation, as they looked for any sort of error, and found none …

“Oh, shit,” I can imagine one saying to the other, who must have nodded with melancholic numbness before replying “We are sooo screwed!”

While every scientist wants to eventually be a pioneer who is proven right, very few actually relish challenging the status quo:  it’s very much like deliberately trying to capsize your own boat in shark-infested waters. While bleeding profusely. To extend the metaphor, the more broadly fundamental the chalenge to orthodoxy was, the more sharks there’d be, and the more frenzied would be their attack …

The results of this experiment had incredibly far-reaching implications:  it could imply either that the calculated characteristics of the Aether were wrong, or that Newton’s absolute time and motion were wrong – which in turn would completely screw up all of Newtonian mechanics, and, damn it, it wasn’t good enough to prove that the world’s complete understanding of physics was wrong: someone was going to have to come up with theories that explained everything Newton’s did, AND explained these new facts, as well!

If you’ve never really learned much about Physics, it’s worth pointing out, at this juncture, that Newton virtually invented theoretical physics – virtually the entire science rested on the laws that Newton had devised:  gravitation, inertia, thermodynamics, motion, and most of the theories involved with time, space, and light.  And every single bit of it depended on the principles that Michaelson and Morely were about to prove flawed …

I feel fairly certain that both men updated their resumés.

When they published their paper, the academic world pretty much went berserk:  some vociferously claimed that the results were flawed, never mind that they couldn’t explain how they were flawed, but they simply had to be … others immediately set about adjusting their mathematics to explain how the results could be true, and yet not completely screw up everything they knew about physics (two of the nuttier of these proposed that everything could be explained if we just assumed that objects in motion shrank or expanded, depending on their velocity, so that a foot ruler moving in a particular manner would still seem to be a foot long while actually being a little shorter or longer than that – exactly enough shorter or longer to achieve the results everyone had expected in the first place! Weirdly, this would turn out to be true, but not for anything like the reasons it was postulated …)

Fortunately for everyone concerned, there was a weird little 26 year old mathematician, working for the Swiss Patent Office, who liked to spend his spare time just thinking about how stuff worked …

Einstein began with the assumption that what the experiment seemed to show, was, in fact, true:  there was no Aether, no absolute reference with regard to space, time, or motion, and the speed of light was a fixed constant. From those assumptions, he began to devise “thought experiments” just to see what the implications of these ideas were.  Then he began to describe these implications mathematically.  He found, with some careful thought, that they did not replace or destroy Newton’s models – they simply refined them: his refinements, referred to as the Special Theory of Relativity, worked out mathematically identical to Newton’s mechanics at the low velocities we encounter in our daily experience, but they yield very different results as one approaches the speed of light.  Violá:  a theoretical framework that explains everything Newtonian mechanics had explained AND the results of the Michaelson-Morely experiment … As an encore, he then went on to write an entirely new theory of Gravity, one that worked way better than Newton’s … that one was called General Relativity.

(What about the nature of light? If it wasn’t waving Aether, just what was going on? Well, it turns out that a whole ‘nother important theory came along about then: Quantum Theory which described light as discrete little packets of energy that oscillated according to the energy contained in the packet … essentially, light didn’t behave like a particle, or a wave, but borrowed characteristics of both. So, no Aether.)

(BTW, Einstein’s math did NOT, in fact, prove that nothing could exceed the speed of light: what it did prove was that any object possessing mass that somehow reached this speed couldn’t be described with valid mathematics – the terms begin to resolve into quantities that can’t be defined in terms of any math Einstein was familiar with.  In practical terms, as something approaches the speed of light, it becomes increasingly massive, making it cost more and more energy to accelerate it, while its length in the direction of motion shrinks, making it harder and harder to advance in that direction, and the passage of Time slows down … if one ignores practicality and just assumes the speed of light is reached, the equations begin to yield mathematically undefined results, involving infinite energy, infinite mass, infinite time, and zero length.  You can’t do useful math using these terms, in much the same way that you can’t do useful math if division by zero is allowed.)

(Somewhere out there, a future rebel is saying, “well, how come we can’t divide by zero??? Who made that the rule???”

Look, I sympathize, ok? But the rule is there because if you don’t apply it, that brand of math can show any number is equal to any other number, which makes that form of math completely useless in describing how stuff works … if you don’t believe me, google ‘division by zero’, and you’ll find explanations by people who, unlike me, actually understand mathematics.  If you like, you can then google ‘speed of light’, to check up on the other stuff I’ve been saying in this blog, and, if you still aren’t content, you can google ‘pain in the ass’, where you may very well find a biography of yourself, along with a mug-shot …)

(Another future rebel is, at this point, almost certainly saying “Well, ok, but that just means no one’s come up with a revolutionary new theory to replace the revolutionary old theory, that replaced the older revolutionary theory, that had replaced everything that went before it! Someone in the future could come up with a new theory and we’ll have starships and colonies and other cool shit like in Star Trek!”

Yes, technically, you are correct. But, future rebel, aka pain-in-the-ass, the revolutionary new shit still has to explain everything the revolutionary old shit explained, and, it would have to explain why every single experiment that’s been performed regarding relativistic changes in mass, length, and time, has so far resoundingly supported Relativity … all that having been said, a revolutionary new theory is needed, as you’ll see if you keep reading – I just don’t think it’ll prove what you want it to, however much we both want it to!)

This sort of brings me to the state of things, today … all that history I just made you read is relevant because A) it shows how any new theory has to meet and defeat the same challenges the old one had to, and B) it illustrates the way things get when something new is required – when things increasingly fail to be explained by the established ideas, or when the old ideas have to have all sorts of corrections and additions, and special cases applied, in order to continue making sense.  That sort of thing is going on right now:  the things Relativity, both Special and General, were devised to explain, they still explain extremely well – but there are other things that are not explained by Relativity at all, and for those things you need Quantum Theory. And the two don’t mix well. At all.

Relativity describes things at high speeds, and things that operate over great distances … Quantum Theory describes things that are ultra small, ultra short-lived, and ultra close to one another.  Relativity encompasses a majestic orderliness, while Quantum Theory describes an almost chaotic, near anarchy – one where chaotic functions themselves induce a strange kind of orderliness, like water rushing turbulently through a gorge:  the water chaotic but the course of the river stable and predictable …

Remember how, in order to make sense of the observed properties of light, physicists completely invented a theoretical substance that was not observable through any ordinary means? Well, they soon did it again …

In the 1930’s, studies of relative velocities of Galaxies, and the gravitational interactions those velocities implied, revealed a disturbing fact:  when you went about calculating how much mass there had to be to account for those interactions, the math didn’t work out. At all. I’m not talking about some piddling little discrepancy:  I’m saying fully 83% of the mass that should be there, simply wasn’t if one judged only by the matter that was detectable by telescopes of various sorts.  Stars, dust clouds, enormous stretches of hydrogen gas, and the galaxies and star clusters which were composed of these things, all had masses that could be calculated, in various proven ways – and when you added it all up, there simply wasn’t enough of it there, to make sense of the motions that were being detected and measured …

Well, hell, that won’t do at all. Something had to be done! 

So, like the phlogiston invented by chemists to explain combustion before they knew how it really worked, and the Luminiferous Aether invented to explain light’s wavelike properties, before they knew how that really worked, everything would be fine if they postulated something to explain all these weird galactic motions until such time as it gets figured out how that really works!

They invented a substance called “Dark Matter” … matter completely undetectable by any means other than gravitational interaction. Sound vaguely familiar?  The theory went that this Dark Matter, and the equally strange “Dark Energy” invented to explain certain other anomalies of a similar sort, made up an enormous percentage of all the matter in the Universe – enough that, depending on which measurements you accept, it could effect the long-term fate of the universe … if it were sufficiently massive, the expansion of the universe would eventually halt, perfectly balanced;  just a little bit more massive, and the whole thing will collapse in time into a “Big Crunch”; finally, if it’s less massive than either of those, the Universe will continue to fly apart forever, like a balloon that can be inflated indefinitely.

Here’s the thing:  every attempt to detect dark matter has fallen short of proving its existence. Just like attempts to detect the luminiferous aether.  That leads to one of very few possibilities:

– Have faith, the Dark Matter really is out there, we just need to find some other way of verifying it, OR

– Einstein’s Gravitation Theory, General Relativity, could be wrong. If so, as noted above, something will have to be proposed that explains everything General Relativity did, AND explains the discrepancy that Dark Matter was invented to account for. This would be a major pain in the ass. It would also force virtually every physicist out there to relearn everything they thought they knew, regarding gravity.

I said virtually every physicist out there:  the ones who won’t have to relearn everything are the ones trying to prove they already have an alternate theory.  These come in two flavors:  Modified Gravitation, and Quantum Gravity.

The modified gravitation guys contend that, rather than postulate an undetectable substance to account for the math not working out, we should alter the math to account for what’s been observed.  Instead of postulating a single unexplainable physical substance, these theories postulate a whole bunch of mathematical corrections, special cases, and jigger factors to make the math work.

To me, that seems like cheating. Remember how, in the wake of the Michaelson/Morely experiment, some physicists tried to make everything all better by playing bizarre games with the math? The Modified Gravity proposals strike me as much the same sort of legerdemain.  There’s a principle known as ‘symmetry’, which supports the idea that the more elegant and uncluttered the math associated with an idea is, the more likely that idea is to be correct.  It’s a sort of cosmic version of Occam’s razor, and, while it is in no way a rigorous test of scientific theories, it has, by and large proved true:  theories that explain a huge number of physical phenomena, tend to be extremely simple and elegant in their formulation.

That leaves us with the other main contender:  Quantum Gravity.  I mentioned earlier that Quantum theory and General Relativity don’t get along:  that’s so, because, when you try to use the equations of General Relativity to describe events at the atomic, and sub-atomic levels (remember back when you were told that an atom was a tiny little solar system?), the results come out as nonsense;  similarly when you apply Quantum theory to larger, grander structures, the results are inconsistent with those predicted by Relativity.  Einstein’s gravitation pictures the universe as an infinitely thin rubber sheet, that is bent, or warped, by the presence of matter.  No matter how closely you look at this space-time continuum of Einstein’s, it is universally smooth and shows no sign of any structure at all. Quantum Theory, in contrast, says that at extremely small levels, there is structure to the continuum:  what they refer to as Quantum Foam, a sub-atomic-scale, turbulent, chaotic froth of little blocks that underlie absolutely everything, and are susceptible to explanation only by the bizarre laws of Quantum Mechanics.  According to theory, these little things are so incredibly small (being the Plank Length, a term devised to describe the ultra-good-God-that’s-tiny distances used in Quantum calculations) that there is no conceivable way we could ever detect evidence of their existence (and, wow, isn’t THAT sounding like a broken record!)

About 15 years ago, however, one Giovanni Amelino-Camelia and his associates, figured out a method by which the foam could be detected:  it depended on detecting the manner in which photons interacted with the foam …

Great. All we have to do is find some photons that all left their source simultaneously, and at the same level of energy. Pointed at Earth. The we compare their energies and see which ones changed. Simple. (Note heavy use of sarcasm, for when I have to eat crow in the next paragraph …)

As it happens, there is a way to do all those things, making me, in this instance, one of the CMJ’s I mentioned back in the beginning of this long, drawn-out diatribe.

From time to time, extremely massive rotating stars collapse in on themselves, and release a freaking ginormous burst of Gamma Rays – highly energetic  photons. If you could detect a few in very close proximity to one another, they should all be of identical energy, since they would have been created in the same part of the event, at the same time.

NASA’s Fermi Gamma-Ray Telescope was put into orbit to detect exactly this sort of thing, along with a lot of other information that could be gained from studying Gamma-Ray emissions. Data from all sorts of Gamma Ray events are continuously recorded and downloaded – enough data that it often sits around waiting for someone to have the time, resources, and energy to examine it.

In May of 2009, the telescope recorded details of a Gamma-burst from a 7 Million year old collapsing star. Not long ago, researcher Robert Nemiroff and his colleagues at Michigan Tech finally had time to take a close look at the data.  He wasn’t specifically looking for this particular phenomenon – but he recognized it when he saw it:  3 photons, detected in close proximity, within 2 milliseconds of one another. Among the zillions of other photon strikes detected, Nemiroff had found 3 photons that could be shown to have formed nearly simultaneously, and in nearly the exact same place – which means they’d remained close together, undispersed, while traveling 7 million light years.  For seven million years these little packets of energy had been zipping through space towards us. All kinds of things could have spread them out;  according to theory, the Quantum Foam should have spread them out.

But nothing had. Nothing at all. Very bad news for the Quantum Foam guys, and yet another victory for Einstein.

It’s not proof that there’s no Quantum Foam – though it very strongly suggest that any foam there might be is way the heck smaller than the Plank Length, and all the guys whose calculations show that the Foam has to be at the Plank-Length scale need to redo their math. All of it.

That’s where we are today:  Quantum Theory and Relativity are locked in a death struggle which neither can win.  Why can’t we just accept that there’s one rule for big things, and another for ultra-small things? Well, remember the Symmetry principle I mentioned? The one that implies a true solution should be elegant and simple?  Two different laws running the universe is not elegant, and it is very far from simple! According to symmetry, there should be one single set of mathematical laws that explain absolutely EVERYTHING …

Einstein referred to it as a “Unified Field Theory” and spent the latter half of his life striving for it. Particle physicists are trying to locate particles that could get us a step closer to achieving it. Other theorists are out there working with equations that imply the Universe must have 10 or 11 dimensions, and that everything is made of of little strings that vibrate in different ways. No one has any real proof that their preferred way out of this dilemma is the one to save the day. Things are at about the same state of confusion as they were right before Einstein published his papers and changed everything.

We’re waiting for another Einstein to show up.  I hope it’s soon:  I can’t stand waiting to see how this will all turn out!

Advertisements

~ by dourscot on September 7, 2012.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

 
%d bloggers like this: