McGuireville Arizona

McGuireville Arizona

There is nothing here in McGuireville except Arizona, and if you don't like that, then you should stay home. I just had a month long journey along the Pacific Coast and down the Rocky Mountains which was pretty amazing thing for most people, but I did it without really thinking too much about it.

Remembering how cold it was in some places is interesting. The coldest place along the early trip was Spokane where there just didn't seem to be any warmth in anything or anyone, it seemed colder than a night I spent in Central Oregon where it got below freezing. The next place it seemed kind of cold was up in the Yellowstone Park. Butte and Bozeman didn't seem that cold, and in fact Bozeman is one of the loveliest small college towns you will ever find.

But Yellowstone was cold, and the Grand Tetons were not. Glenwood Canyon was not cold, but those Colorado people are busy busy busy, and not really friendly. I liked Glenwood Springs downtown a lot, and those hot spring pools sure look nice. It was cold again going over the Tennessee Pass at 10 thousand feet, and I sang in the car to make my lungs work so that I wouldn't get nauseaus like I used to do at high altitude. Down in Salida it was warm again, and on a Sunday noon, the local police were on the ball, noticing me coming into town the back way and so on.

From there I got into Taos, and it was cold both nights at the rest stop by the bridge. There was a guy living in one of the shelters with his motorcycle, I don't know where he went during the day. But it was sure cold at night. On the second day in Taos I got a shower and a short swim at the city pool, feeling the 7 thousand feet and taking it really easy. Boy the water in the pool felt clean, I wonder if it has anything to do with air pressure and the way the air can't hold up the dust particles up there. The water was really clean, and felt like glycerine.

Those were the cold places, Spokane, Yellowstone, the Pass, Taos at night. CouerdAlene was warm, so was Medford and Bend, and Butte, and Missoula. and Bozeman. The pass down into Sante Fe was fantastic in fall colors along the river, but Poajoque was grim and dusty, and Sante Fe was not exactly cheery. Albuquerque seemed a little gay, I dunno just the people in on some private joke. In Gallup its better, they smile and are relaxed and pay attention to strangers, and in Flagstaff its fine, people are enjoying life.

Where I left off last time was with Harry Potter waving a dowel rod. The spell he might be casting is whether it is going to rain or not. If the barometer falls, the weather is likely to turn bad. If the barometer is stable, then no change. So if you were a Connecticut Yankee in King Arthur's Court, you should be able to use a stick to predict rain, and people will think you are a witch.

But its worth a discussion of what might be happening to the air molecules when you wave the stick. In dry air when we hit the molecules with the stick the nitrogens are likely to have a high angular momentum, but the stick is overwhelming. So the nitrogens get kicked pretty far, and since they are rotating, they precess when they hit other things. This is turbulence. The oxygens behave similarly but with less angular momentum they get bounced around, and they don't precess, so the overall effect is diffusion. You could do a statistical analysis and predict the turbulence in a statistically predicable way, if this model is close to what actually happens.

Another thing to consider, before adding the water, is local changes in the number of molecules (changes in pressure). If the nitrogen goes pretty far there might be local change in pressure near the stick - that is low pressure - as in a wing. It seems likely that the nitrogen vacates the area faster than the oxygen. The oxygen then is in a region where collisions are less likely. The oxygen expands to fill this gap, absorbing heat, and cooling its environment.

This is a pretty far fetched description of waving a stick, but it might be close to what is going on. You bash the air with a stick, and the nitrogen and oxygen behave in somewhat different ways, causing turbulent flow. Once I worked out a similar model for the expansion of gas. In this model, when the air goes through the nozzle, the oxygen expands somewhat explosively compared to the stubborn nitrogen. In this model I imagined that the oxygen expansion forces the nitrogen away, forcing the translation explosively and leading to precession and turbulence.

But these two motions are fundamentally different, bashing the air and expanding the air, although both result in turbulence. It may be that there are two different kinds of turbulence, one from an overwhelming collision with a stick, and one from expansion as from a nozzle. There may be two kinds, but even if that is so, the model to predict the turbulence may be the same for either realm, with slightly different initial conditions.

What happens in turbulence has been a hot topic in the journals. Heisenberg had some reason to comment on turbulence back in the pre-war days. He wrote a mysterious paper in German which I tried to read once, and von Karman (who as Hungarian) was offended and wrote an angry reply. The debate continued in a not very gentlemanly way, and I think von Karman was offended that Heisenberg would dare to comment on something so far from his field. But maybe it was part of Heisenberg's field, he had to deal with diffusion and so on of moving particles, just as air is moving particles.

What the result was I don't understand. I am not sure what von Karman and Heisenberg thought about turbulence. Clearly Heisenberg's atomic particles were moving in a very different environment, but the concepts should be general enough that one model would describe all motions.

To confuse the issue even more, the contemporary mathematician Mandelbrot also weighed in on turbulence, providing some very simple statistical models based on complex functions that produce maps very similar to the development of turbulence. When considering the von Karman/Heisenberg feud, it is interesting that the only other similar feud that I am aware of is the Mandelbrot/Herbert Simon feud concerning probabilities in natural language.

Either way the turbulence problem is interesting, and the addition of water to the air adds another molecule, one that includes an ionic attraction, and the likelihood of condensing at low pressures. The motion is complicated, the likelihood of condensation is even more complicated, there is probably a statistical likelihood that some water condenses no matter what you do, but all of these reactions can be modelled for the gas in a statistical way so that the system can be fully described.

But the important thing to know about fluids that have magnetic and electric properties is that they swirl when moving through magnetic fields. This is why the water in your sink swirls the way it does. Now, when there water in the air it is natural for it to form swirling patterns, and when the amount of water increases it is probable that the swirls will become larger in diameter. GK Bachelor's book covers the theory that there are various values of atmospheric swirling that are stable, and that the system will seek one of the stable patterns of rotation.

In the case of our atmosphere filling with water due to warming, the larger diameter swirls are predictable. Under these swirls the arctic zones get a regular dose of warm weather and there is a danger of the icepack melting. But what seems to be happening these days is that the atmosphere is filling with water, and when it is generally "full" it is dumping ALL of the water as rain, flushing the land and cleaning it. If I am not mistaken this is the same phenomenon that people wrote about in 1810 just after the Battle of Tippecanoe. There was an earthquake, the river ran north, and it rained for thirty days.

The whole thing might be caused by the reversal of the planet's magnetic poles, something that might have been triggered by a nuclear explosion or bomb. It has happened before, and is probably not serious enough to require new fangled high tech vehicles populated by healthy young men and busty young women looking for a place to settle down. its not as serious as the reversal of the earth's poles. "Oh, the magnetic poles reversing. Nevermind."

Fish Creek

Fish Creek Idaho

Sometimes it seems like you have to go a long way to get back to some wilderness. But when you do, it sure is a sight to look at. When I get to wilderness my eyes just go Ahhh! when I look at the trees changing color, the brown moss in the river, the silvered decaying tree trunks, and the white light bouncing off the ripples in the water. It is a sight, some places better than others, but when you know you are in a place that has never really been disturbed, you can take a look and try to memorize it. Last place I was at that made me feel this way was in New Mexico, a place where folks said "there are elk back here, if you look, over the top of the scrub, back behind where the farm is, over toward the mountains" And I replied, well I saw an elk once, and it was like nothing else, but for me it is enough to see the red light from the setting sun hitting the tops of the mountain, and lighting up the snow. The folks both looked, and we didnt say anything more.

Well the last time I wrote was pretty upsetting, the Salinas Creek entry was written about four days after the hurricane hit New Orleans. Way back in my life I was a hydrology simulation computer programmer for flooding on the Mississippi. I didn't know much but I learned about what they call rain graphs, hyetographs, and how the government engineers decide which projects are the most important to do for flood prevention. After the government engineer prioritizes, Congress and the President approve the projects, and it usually doesn't have anything to do with what the engineer said, so I eventually gave up on that career.

But I did learn enough to know for sure that New Orleans was likely to flood, and it turns out that the encylopedia that ships on Apple Computers also mentions that it is below sea level. So it seems like pretty common knowledge that it would flood, its in the encyclopedia. Look it up in your Funk and Wagnalls. So the day I was writing in Salinas was the day that Matt Lauer kept saying over and over that no one imagined it would flood, and it was more obvious than usual but Matt didn't know beans about floods. That was the days when the TV was filled with images of people near despair because they had been trapped by flood waters for three days and there was no sign that they were about to be rescued, or given any water, and meanwhile the commentaters on TV were eternally damning them for reports of lawlessness and looting.

Because I knew for damn sure that FEMA was supposed to be there after an emergency, because the local government was gone, it was unable to cope, and where was FEMA? It had to be deliberate that FEMA was not there, there are too many dedicated career professionals for this to be a random fuck up. The whole organization fucked up at once, systematically. And the only reason I could think of for FEMA not to be there is the President didn't know it was going to flood, he thought it was only going to be an average emergency, and he wanted the locals and the Red Cross to handle it, so he could say we don't need FEMA. But how do you prove that? I guess I don't know how.

So I think if you read the Salinas entry you can tell I was upset, just from the grammar, and the continuity, I edited some stuff out badly.

Anyway, I said I wanted to talk about magnetically aligned fluids, which I do, but in thinking about it I realized there is just a heck of a lot of stuff I need to go into first. I need to talk about vortexes, and how there is a speed at which the dimple forms - such as when you stir the coffee with a spoon. I need to talk about Kutta-Joukouski transformations, which are a fancy mathematical way of transforming the shape of a wing into the shape of whats called a "hodograph" - or a graph of Navier Stokes pressures that will be generated by the wing. All this stuff is covered in the Milne-Thompson book on aerodynamics and the neat things are that you can make a hodograph, and if you do a complex transformation on it you get a nice shape that looks like a wing crossection. The vortex is important in wings because you can model the flow over the wing crossection as two vortexes, a large one and a little one, do the hodographs and check the pressures, adjust it, and convert back.

In the old days it was the only way to go, and time consuming to try to optimize your wing. I have seen some recent work and it seems like what they do now is finite point analysis without the hodograph conversion, because digital computers can do the grunt work, but they can't do the complex transformations as easily. I guess it probably used to take a few days to analyze a hodograph and convert it to a wing shape, and then you generate some approximate vortexes and try to minimize the size of the smaller one.

In a wing the wasted energy is in the wake. The equations for wake vortices were worked out by von Karman, and these are the nastiest equations I ever saw, including some equations worked out by Nernst for the solution of electrolysis problems. The von Karman equations are nearly impossible to visualize but if you can minimize the wake turbulence you can optimize your wing. And most of the wake turbulence is in the wingtip vortices.

Now one of the things about vortexes is that there is an angular speed beyond which "flow cannot be contemplated." Milne-Thomson has some nice equations for this, and a diagram, and the coffee cup is the most comfortable example for most people. It also is the subject of a 1914 paper by August Betz about how to create a vortex in an inviscid fluid. The idea here is that without viscosity you can't generate continuously differentiable flow velocities throughout the fluid. You can't make a vortex. Betz uses the coffee cup as an example. The cup, not the saucer.

In hydraulics they talk about cavitation in a fluid, where an object moves so rapidly through the fluid that the fluid cannot move quickly enough to fill in the space behind the object. As Ogata says: "When the velocity of the liquid flow is increased locally and the liquid flows into a region where the pressure is reduced to vapor pressure, it boils, and vapor pockets develop...the vapor bubbles are carried along with the liquid until a region of higher pressure is reached and they suddenly collapse." The collapse causes the noise and vibration.

Now if you are a nice swimmer doing a crawl, and you stroke your hand straight into the water you might push an air bubble or two under your fingernail. But if you do it just right you can see air bubbles continuously forming during the downstoke into the water. Its continuous, its only under the longest finger, and as the bubbles peel off only one or two of them (out of a half dozen) reach the surface. You are cavitating!

This illustrates that these kind of effects are fairly common. Another example that might make you think is streamlining of a car. I have a van, and I just measured that it reaches its maximum height of 6.5 feet at a distance of 5 feet from the front bumper. It is not very streamlined compared to a sportscar that might be no more than four feet high. If I approximate the front end of my van as a 6.5 foot circle, then the center of the circle would be at ground level about 1.5 feet behind my front wheel, just under the door handle.

So now if I look at the air flowing past my car as air moving past a non rotating disk I find something interesting. The angular acceleration is a function of the velocity squared, over the radius. The critical acceleration would be the one that accelerates some molecules up to the speed of sound. For my van this works out to be 58.9 MPH - the same speed at which the air over the van starts to whistle and whine.

Now for the sports car, so low to the ground that it is approximately a 50 meter radius, with the center being 49 meters below ground, the critical acceleration, when all the air whistles, occurs at about 292 MPH. It is quiet, the air almost never whistles like a truck, or a van, or an RV.

Similarly I once worked out that a baseball generated accelerations over 2600 MPH, or Mach 3.5. Talk about heat! And curveballs, at 1800RPM are Mach 5 in acceleration, high enough that some O2 molecules might dissociate.

Finally, if you take a foot long dowel rod you can tell how humid it is by swishing it through the air like Harry Potter. On a dry day you can make it whistle holding it in the middle. On a wet day, when air pressure is lower, you have to hold the rod by the end to make it move fast enough to whistle.

So here we have some examples of cavitation, streamlining, and accelerations that are as fast as sound, not by creating high speed air flows, but by making the fluid change direction through various means. We still don't know how everyone in FEMA screwed up at the same time, and we still don't know why the new FEMA manager came on board and said, as if he were Matt Lauer, that the hurricane caused "unimaginable" damage. Because it was imaginable, and every disaster plan imagined it, and every flooding expert in every water district in the whole country knows it.

Salinas

Salinas River

Up in Salinas there is a tiny state park along the coast. There is hardly anyone around, and its a good place to go for secluded shoreline, with a few fisherman around to remind you of whats good for you.

While I was talking about Feynman I was thinking about a professor of mine that had a great influence on my thinking. He was part of an interesting experiment back in the 1970's where engineering students got trained in thinking about things as systems. Kantor had been a physicist, but he got involved in the "Save Lake Erie" project in the 1960s, and after they saved it, he stayed involved in teaching the interdisciplinary approach.

So I took his introductory classes as a freshman, and he had some very good material that he introduced to me and a bunch of other students from a lot of different disciplines. I was very interested in his class, and found the material and the presentation more interesting than any of my other work.

Now by the time I should have graduated this curriculum had developed even further, but the students were no longer interested, and the complex systems department was cancelled. Kantor stayed around for awhile and was quoted in the student newspaper as wondering why the program had been cancelled, and saying he still had the class notes for the classes he used to teach.

Now thirty years have gone by and I have an impression about the question as to whether complex systems was worth it. As a freshman engineering student it was a dangerous thing to teach me how to think. Up to the 1960's and through the JFK shooting/war years engineering schools had developed an approach of "damn the torpedoes, teach the kids the fundamentals of science" Kantor's approach was somewhat contrary: "teach the kids how to think and how to apply concepts across disciplinary lines" This is working against the engineering deans who are trying to cram as much stuff into the student's head in the four short years that they have him.

Now which one is better I don't know, there is simply way too much basic engineering to learn in only four years, and so much specialization that every engineering school is required to teach a specialty on top of the basics.

So when I was in school they were still cramming the stuff in as fast as they could, hoping to familiarize the students with all the basics. And what happened to me was that I got the reputation for understanding things, being able to apply the time lags and dynamic responses from electronic circuit theory to my daily life - such as how long I had to study something to retain it until the day after the test.

This was not especially good for my grades, as I was distracted by it, and so I was behind on a lot of classes. The best classes that I could have benefited from were thermo, fields, and linear algebra, and since those are essentials, you can say that I never got the basic engineering education. But Kantor taught me how to think, so maybe I learned as much as the others and then some. They never recovered from cramming, but they are more familiar with it if they need it. Me on the other hand, I dropped out mainly because I had been taught to think, and I can still think. Thermo and fields don't seem that hard to me, but the homeworks seem redundant and boring for what I want, but I never got that good degree. Seven years as a sophomore, down the drain.

So I think Kantor's stuff is incompatible with engineering the way it was taught in 1978. But it's good stuff! As interesting as a taped Feynman lecture! And what good are a bunch of educated engineers if they can't think. They get to be like the NASA guys, who are commonly described as being on happy pills. The things they say and do are so incompatible with reality, and so much under the microscope, that they seem high.

Anyway all this talk about alternative approaches to the problem - what IS the problem anyway? - reminds me of something I read a few years ago in some old papers that came out of Germany. Written during the war these papers did not get published at all until the early 1950's and never got the widespread distribution that they would have gotten if they were published in Journal of Fluids.

But one particular paper stands out as a direct contrast with the important work by Kantrowitz that I talked about earlier. This work casts new light on his little known work, work that I said was never famous in the first place. German science had faced a similar problem with combustion calculations and had tried to solve it using electron spectroscopy to find out what was happening with the atoms. The paper I read had a different focus - the particular problem to be solved was to find out how much vibrational heat different molecules could absorb.

The German approach began by talking about electron shapes, vibrations, and molal heat absorption rates, and so on. Its a pretty big contrast with Kantrowitz and I think it is a demonstration of the American approach to problems: fiddle with it. American engineers have inherited techniques from Yankee tinkerers so that from Edison to the Wright Brothers, to Hewlett and Packard, and Jobs and Wozniak, our development comes from tinkering in the garage.

The apocryphal story is that Edison found thousands of ways not to make a light bulb, but on the other hand when the German Nernst invented neon, he did some math, said to himself "this ought to work" and went out in the lab and built it. It worked the first time. To finish off this good story about American tinkering there is a good argument to be made for the fact that tinkering with Model T trucks and cars gave the Americans a huge edge over Germany during the war - we had thousands of men who were able to tinker with a two and a half ton truck and keep it running, and the Germans did not have anything like that. On the other hand, they had some pretty fantastic technology at wars end including rockets and jet planes, and guided missiles.

If you watch the movie "Where Eagles Dare" they also had a helicopter and some little cars that were very light weight and ran on electricity, if you listen to the engines whine. Now if you want to know why I think they were light weight (no batteries) then just watch them when they flip over. I'm sure the director put in those scenes with the lightweight cars flipping over in order to show that they didn't have any heavy batteries. Either they had a superconducting inductor to store the power, or they had some kind of electric grid intercepting neutrons from a radioactive source the way that a solar panel intercepts photons to make power. Since the war was "almost over", it didn't matter if some soldiers got exposed briefly to high amounts of radioactivity. The war was almost over, and had been since 1940.

Here is one thing the German wartime scientist Shaefer said while discussing his study on the vibrations of atoms:

"an investigation by Kneser on the acoustic absorption and dispersion in gaseous Nitrogen Oxide between frequencies of 300 to 3000 cycles per second was made for determining the speed at which the excited state above the basic state of the NO was formed. This excited state differs from the basic state merely by a changed spin adjustment and furnishes a noticable contribution to the molal heat in the temperature range at and below room temperature."

This kind of talk is quite a contrast with Kantrowitz's unsupported speculation that vibration rates might have something to do with his combustion problem. In addition it raises the interesting speculation that music that resonates on 300 to 3000 Herz will also warm up the molal heat of the air in a room, through spin. I think this is so, my experience is that music warms up a room, and I also think that the photons in sunlight also contribute to the molal heat of a gas through spin. The photons make the N2 molecule spin. In my opinion these are the reasons why the Hopi character called Kokopelli is generally shown playing a flute while making some soup in the sun. The soup pot is generally mounted on a flexible leather blanket so that it can more easily be made to vibrate. Kokopelli was right - cooking is better when done to music while out in the sun.

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PS What Shaefer was doing was measuring the atomic vibration characteristics and their ability to absorb energy during short periods. They were studying the heat characteristics of the atoms in order to support studies of the Raman effect - the way atoms diffuse light. They found that molecules were more likely to accept heat from translational collisions with other molecules, rather that from the unlikely vibrational collisions. In addition the German scientists found that the more complicated longer molecules or angular molecules did not generally maintain a symmetric form, but varied their forms in a statistical way depending on the rotation of their various molecular components. They speculated that it was possible to align the angular molecules using magnetic fields, a topic I want to talk about tomorrow.

San Simeon

San Simeon

San Simeon is nice when Southern California is just too hot. I have been up the central coast a few times, and I think the next time I go this way I am going to stop at San Simeon for a few days, and then turn around back to Morro Bay and get on the freeway there. The coast highway used to always be packed bumper to bumper. It is not that way anymore, but it is so long to drive and is so often socked in, that I don't want to go.

One thing that my writing subject reminds me of is listening to the Feynman lectures from Cal Tech. Richard Feynman was one of the mathmaticians who got involved in Manhattan project, and in the early 1960's he gave a series of lectures at Cal Tech which were tape recorded.

Now Feynman is a very interesting guy, his books are terrific, and reading his books makes science pretty enjoyable to learn about. It is all the more true when you listen to the audio tapes of his lectures. Remember that in 1961 America was still pretty aggressive about schooling of engineers and scientists. The Kennedy assassination had not happened yet, so the country still had a single mindedness about what it meant to be American.

Anyway for the recording of the crowd during Feynman's lectures I got a sense that the social expectations of the students was completely different from what I experienced or my what the older draft dodging seniors experienced. In addition to the serious and competitive students, Feynman himself is interesting to listen to, he has a Brooklyn accent, and he was not accustomed to lecturing with sound amplification equipment. So what you get is someone who sounds like Groucho Marx yelling at you about muons and atomic spin, and that kind of talk, and you just about expect him to tell a Groucho Marx joke.

But he doesn't tell the jokes, and the fact is nuclear physics is not funny, its just not funny, even though listening to Feynman you expect to be laughing any minute. What you do get from Feynman is the repeated warning that nuclear physics is simply not like anything that people have ever experienced, so when people give physical analogies from our own experience, Feynman reminds us over and over that it is really not like that. The analogy might be helpful temporarily, but in the end the analogy is likely to leave a more people confused than it actually helped.

So yesterday when I gave my analogy of nitrogen tennis balls, and oxygen windmills, that is not really what it is like, and the analogy may be helpful to some people for a while, but it is likely to be confusing to more people in the long run. Things that happen in the scale and time of nuclear particles or molecules simply are not like things we experience in every day life. And that was the most important lesson I got from listening to Feynman, that and the realization that the social expectations of American nerds was quite a bit different in 1961 than it was when I went to school.

Feynman's idea that things are not the same at the molecular atomic or nuclear scale is important. For an illustration let us take the concept of entropy and enthalpy. People will talk about entropy, how the amount of organization or energy in a system tends to run out. People talk about systems running out of energy and give examples from the physical world like erosion, or food chains, and human beings being highly organized organisms and stuff like that.

But realistically we know that the things that have the most energy are photons. These are massless things which are pure energy, in contrast to a hydrogen molecule which has a great deal of energy stored as mass. If E=MC^^2, then you have to realize that something with mass is actually a low energy thing, the energy has congealed down into mass. If it was more energetic, it would still be photons and nuetrinos, but it has experienced entropy, it is all run-down, and is now a physical thing with mass.

Similarly, with time, the photon is a thing that cruises along with Mass=neglible and speed equal to the speed of light. Time has practically stopped for the photon, time is something that is not a meaningful variable for photons. If you were a photon doing laboratory experiments time is not a part of the external environment that would interest you. You would not have to account for time, or for any method of keeping time constant - if you were a photon there would be no time. As a photon you have to lose a lot of energy to become interested in time, you have to become some low energy thing with mass before time becomes a factor.

So for this reason, in the old Star Trek, they always measured time in terms of Star Dates. Because the stars all had a large amount of mass, they had the most consistent and regular amounts of time. Measuring time in terms of the time experienced by stars makes the most sense, even when compared to time on earth, where the earth is moving pretty rapidly around its star, and has a different density. Because of this, "earth time" or "time as experienced by a planet" does not make as much sense as "Star Date"

So how should we look at the arguments people make about entropy? Well the ideal state is to be photons. The least organized, most entropy, things are heavy metals. Human beings are somewhere in between there, some improbably complicated collection of DNA proteins and amino acids that is really quite low on the cosmic scale of entropy. Like the curlicues and gnomes on Gothic Cathedrals, they are striking, but they are representive of a low state of things, even though the complex nature of the heavy atoms seems quite unexpected and interesting. Diffraction patterns of waves through a pattern of slits is also interesting for the same reasons of complexity. But low energy - high entropy!

Anyway, Star Dates are because that is the only "time" that is constant for both starships and for people on earth. And nuclear and atomic things cannot be explained using "real world" analogies, because they are not "real world" And life forms represent an oddity in the entropy enthalpy scheme of things, an interesting oddity, but an oddity none the less.

La Jolla

La Jolla California

La Jolla is fun, its a bit more uptown than Mission Beach. Here the surf is about perfect for learners, all day long the waves run two to three feet, with a nice break all up and down the beach. A few hundred yards north of here is the Scripps Oceanography Institute. They take in a lot of ocean water all the time for their laboratory experiments and there is an outfall up there that dumps their used water onto the beach, 24 hours a day. If you go up on the cliff and look, you can see the different colored water from the outfall trailing away out to sea, drifting south and west until it gets beyond sight down near LaJolla point.

There are a few interesting stories about how some rivers and streams do not mingle their waters when they meet a tributary, and this is similar to that. I have sometimes wondered if the Scripps water floating on the surface somehow makes the surfing waves more stable and consistent. I suppose that the Scripps water is warmer, from being in their buildings, but maybe it also has a lighter density from less salt, or ionic differences or something.

One thing is clear from looking at the ocean and that is that an offshore kelp bed can make the water more glassy when it gets to breaking on the beach, and maybe the Scripps water helps do this too. Its an interesting question, and as I sometimes say, there might be some small value in looking for the answer, but I am not going to look for it today. But the thing to do if you look at waves is do some Fourier transforms in your head, and try to identify how many wavelengths you can see in the waves. The highest frequency is the ripples caused by the wind, generally when talking about wind you have to include turbulent eddys or "breezes". So there are probably two frequencies of ripples in the water caused by wind.

Then there are the big ripples caused by the surfers or by sea lions, take your pick. These are quite a bit slower than the wind ripples, but are single point sources, and the waves are dampened out by viscosity after only a few inches. Say these are one tenth the frequency of the ripples. Then you have your chop from the ocean, little garbage waves created due to constructive or destructive interference from a multitude of waves. These things must chop along at some natural frequency of the water since by definition they never got dampened. It might be right to assign them a frequency another order of magnitude slower than the sea lion waves. Another order of magnitude gets you to the swell that causes the breaker, and swells come in sets of 4 to 6 waves in between lulls of 4 to 6 non-waves, so sets have a frequency that is another order of magnitude less. Then you have an occasional swell that comes in from another direction. The swell itself has a frequency equal to what the surfers are using, but it disappears for long periods, another order of magnitude slower.

Summing up the Fourier parts, assigning each a frequency that is an order of magnitude different:
ripples caused by breezes,
normal wind ripples,
mammal ripples
chop,
swell,
set,
cross set

The timing between swells is available from the lifeguards, and so from there you can make a pretty nice model of the waves in the ocean. Then you can try to predict what a kelp bed will do, or what different quality water will do, or the Scripps outfall, to make things glassy. If you want glassy. Note that this is not a surf predictor model. There are plenty of those, and they work pretty good, mostly depending on surf measurement and reporting stations in order to keep themselves calibrated.

And I am at the beach now, and as a segue into what I wanted to talk about, let me tell you that when someone says "have a good day" what that means to me is involuntary memories of long summer days in the blue Pacific, whitewater waves falling down, the back pull of the ocean just before a wave picks you up and sends you ashore, boogie board surfing with my friends, and laughter and a little bit of yahoo yelling. I once heard a hardboard stand up surfer describe what it's like to be in a tube of water with the tube closing in, and water spraying all around you and a deafening noise. Have a good day really means something to me. I try not to think about getting tumbled over while out of breath and underwater or getting my skin thrashed against the broken seashells on the beach when a wave threw me up there before I was ready to go.

What I wanted to talk about instead was imperfect gases and something important that a brilliant scientist named Kantrowitz found during the war. It was classified at the time, so it never made headlines, and if you think about it, even Einstein did not really get famous for about 40 years after his two most important papers. I like the other one the most, the one about magnetism.

Anyway Kantrowitz was trying to get the most combustion out of turbines, and what he found was that nitrogen was a little slow in expanding, compared to the rest of the air, the rest is mostly oxygen, but nitrogen was slow. I say nitrogen is "stubborn" and what Kantrowitz measured was that different shaped nozzles helped the nitrogen expand faster or slower which affects the amount of combustion, more or less of it. He was trying to find an extra ten percent of engine power that the math models predicted would be there, but was not actually there when they built the first jet turbines.

But the critical result was the simple observation that under his conditions the air was not an ideal gas. The nitrogen behaved differently than the theoretical models and it affected the observable performance of the turbine system he was working on. You would think there is other evidence of observable differences in air that show it is not an ideal gas. One of these instances of non-ideal behavior might occur near Mach 1. Pilots report an increase in buffeting starting around .94 Mach, or within 6 percent of the speed of sound.

This buffeting could very well be the result of something that is common to all gaseous fluids, but that seems unlikely. It seems more likely that the buffeting is caused by the variations in the gases in the air, some effect that is similar to the Kantrowitz observation that nitrogen is stubborn when pushed under pressure through a nozzle.

It seems like Kantrowitz observed an imperfect behavior of expansion, and the test pilots observed an imperfect behavior of incompressibility. Are these the result of the same imperfect properties in the air? In the nitrogen? One approach to that question would be to ask what kind of observable imperfect behaviors can there be? And to look at that you would start to look at phase changes for each gas, and look at parametric charts of the gas phase behavior under different pressures and temperatures. Langmuir had his people doing things like this, notably Kurt Vonnegut's brother, who identified twelve or eighteen different types of ice, with the ninth type being wholly theoretical and unable to create in the laboratory.

Parametric phase charts would be a productive way to look at the problem, but another approach is whether there are some fundamental properties of the individual molecules that makes a gas behave in an imperfect way. This approach appeals to me a great deal, frankly my attitude has a lot to do with why I never finished my engineering degree, but it appeals to me and that is what I want to talk about today.

I've spent the last couple of years thinking about this, after reading Kantrowitz' paper back in about 2000 or 2001. After about two years I wrote a paper on smartgroups.com/hilsch about how the Kantrowitz behavior is probably responsible for devices that create a temperature difference in air. My position is that the temperature difference is created during the time the nitrogen is too stubborn to expand. During this time the oxygen has to do all the expanding, absorbing all the heat, and making its surroundings colder, the same way the coolant in your air conditioner keeps you cool.

Anyway the oxygen gets hot, and so the nitrogen gets cold, and according to Kantrowitz you have up to about 5 milliseconds to separate them and get a cold flow and a hot flow. After 5 ms all things reach equilibrium - the temperature difference is gone. One way to separate them is with a centrifuge, or spinning them inside a tube, and another way seems to be to vibrate them with sound.

Two or three of my contributions to the smartgroups/hilsch forum are worth reading, and there are a number of interesting papers describing the centrifuge technique which has been known for ninety years or longer. I can never keep it straight in my head but it seems to me that the heavier oxygen molecules (the warm ones) get forced to the outer layer, and the lighter nitrogen (the colder ones) stay in the center of the vortex. It could be wrong, maybe the low density hot oxygen molecules stay in the center. Maybe there is a critical speed where the system flip-flops. I don't care today.

The question I want to know is why the nitrogen is stubborn. Why is it that Kantrowitz found that water vapor or dust made the nitrogen more willing to play ball? Which gas causes the buffeting at .94 Mach? Why?

To answer these questions I think you should ask questions like what shape is the molecule, what is the weight, how does the molecule behave under pressure or temperature changes. You need to consider atomic weights and theory of s p f electron shells, think about ionic potential, electric conductivity or resistance, whether there is gravity or weightlessness, and always remember that the magnetic moment of an electron is 1000 times greater than the magnetic moment of a proton. Heavy things have higher magnetic fields. There are other things to think about too, that are probably outside the environment that normal air works in, such as oxidation, or fission, and others I have never dreamed of. But at some point I am going to want to talk about what happens at hypersonic speeds like Mach 5 or 6, which is dissociation, and at about Mach 8 which is the ionization of molecules.

For now let's stick to gases behaving in the sonic and transonic regions. What I want to consider first is the bi-atomic molecules N2 and O2. Both of them are molecules made up of two atoms, and the theory says that the molecules are probably symmetrical with respect to electric/magnetic fields, and symmetrical when expressing their observable energy through vibrating or translating. In fact you can work out a table showing the different ways a two atom molecule can translate while vibrating, either along the axis, or against the axis. And curiously this makes you wonder if the two atoms are rotating around each other, and if they are is that something that we can measure.

My thoughts on this are that rotation is something that we can not measure, we can't observe it. I suppose that rotation is not something that is expressed by the PV=kRT equation, and wonder where that takes me. The first thing I do is assume that the molecules all rotate at some equal energy level, and that they also vibrate and translate while the neutrons orbit each other. If you look at the periodic table the oxygen atom is heavier, so the oxygen molecule will spin slower and wider, following Kepler, and the nitrogen molecule will be smaller and spinning faster. The angular momentum is the same, but the kinetic energy of the nitrogen is much greater, proportional to the square of the velocity.

So what happens if you picture a chain-link-fence like lattice of nitrogen and oxygen molecules spinning against one another? The big slow oxygen molecules are like 3 foot windmills getting bombarded by tennis balls. Four tennis balls for every windmill. Pretty soon the oxygen stops spinning. The little nitrogen guys are spinning around like crazy bumping into each other, and every so often clobbering up against some big dumb oxygen molecule. When they hit they might roll off, or they might skid up against it depending on their rotation, or they might hit along their axis and just bump off. But the result after a suitable time delay for equilibrium is a gas where the oxygen gets bumped around all day long by energetically spinning nitrogen molecules, nitrogen molecules spinning more or less energetically depending on their last few collisions with other molecules. Quite an exciting game of molecular billiards.

Does the imagined system match the observed performance? Yes. First, what about the case of rapid expansion in a nozzle? Can this model predict what Kantrowitz observed? Yes. Under expansion our model predicts that the oxygen has a very low angular momentum and can easily change its vibration rate to expand rapidly. The nitrogen has a comparatively large angular momentum and cannot readily change its vibrational energy. Its stubborn.

Kantrowitz observation about water and dust could possibly be due to the irregular shapes of these molecules (dust being a suspended solid molecule). The irregular shapes knock the spin out of the nitrogen so that it is not stubborn.

Second, what about the case of Mach .94 buffeting? Does this model handle that? Yes. It could be that starting at about .94 Mach we have reached the sonic speed of some or all of the nitrogen. It can no longer accept vibration as an input to its molecular energy. It behaves like an incompressible gas while the oxygen is still able to absorb energy. Six percent faster and the oxygen is also no longer able to accept the vibration as an input. This is Mach 1. The nitrogen sonic speed, for the spinning nitrogen molecules, has already been reached. At Mach 1, both gases pass along the momentous push of the aircraft like a liquid would, as sound, a sonic boom.

Now oddly, as a final question. Take the familiar curved shape of a Bernoulli wing as perfected by Wilber and Orville and imagine the airflow across it. This wing compresses and then expands the flow across it, creating a boundary layer and a smooth transition in air velocity until the boundary layer separates above or behind the wing. Behind the wing the fast moving low pressure air joins with the slower moving higher pressure air from below the wing, combining turbulently and creating wake vortices and wingtip vortices whose equations were worked out by von Karman.

What do you see? I see the wing as half a nozzle. If you took another wing, inverted it and placed it above the boundary layer, you would have two wings forming one nozzle. The wing and the nozzle are equivalent. The effect observed by Kantrowitz should be observable in wings. It turns out that it is. While working for Langmuir, Schaefer and Vonnegut tested the wing ice found on airplanes. There are gas molecules embedded in wing ice, proving that the air over the wing was cold, colder than the wing itself. It was the air that froze. The converse question is whether the .94 Mach buffeting of an aircraft is observable in a nozzle.

But you can prove the cooling thing for yourself. Drive down the highway on a warm summmer evening. Put your hand out the window just so! The flow from under the side mirror hits your wrist. The fastest part of the flow is cold, colder than the surrounding air. The blood coursing through your hand will get cool, in a few minutes it will be cooling off your whole body. Turn off your A/C! Save on gas! Breathe in the air.

Mission Point

Mission Point Beach, California

Mission Beach is a lot of fun especially in August. Here you can laze around all day reading and so on, and the whole place is crowded with athletic young people having a good time exercising and socializing. You can see surfers going into the water and chatting on their way in and out. Waxing their boards or showering off at the public showers, chatting about the waves, and the last time they saw or talked to so-and-so, or what did they do last Friday night.

Wednesdays is an especially good day for watching aspiring volleyball players. Get to the beach early and watch them drill with their coach, hitting volleyballs while un-self-consciously wearing their bikini. At around 10 AM the late comers arrive and pretty soon you can watch some pretty lively volleyball games between some very talented and good looking volleyball players. You can see the men can bash the volleyball around too, if thats the kind of game you want to see.

All of them are pretty smart people, probably attending UC San Diego or one of the other colleges. The especially talented athletes probably get some kind of scholarship, and pro volleyball has become a pretty good career for more than a few young people, mostly the men.

The whole thing is a little like the paradise in one of the old James Bond films where good looking young people cavort in the sun, playing athletic games and admiring each others bodies while socializing and just generally living the kind of life that everyone would lead if this were some kind of James Bond utopia, without anyone like Dr Evil to contend with.

But Mission Beach is fun, and definitely a beautiful side of our society, even if gambling, drugs, cable television, adult movies and liquor is a big part of their lives. It works for them, at least for now!

Anyway I have been coming down here occasionally for about 20 years, and when I do it often seems that I will see a formation flight of F-14's taking off from Miramar and heading out over the ocean. Presumably the flight leader is taking the other crew out to practice carrier landings somewhere out at sea, but you never know, and it doesn't take more than a minute for them to get too small to see, and only a few more seconds for them to be beyond the horizon, which is also out of radar range.

But I don't have any radar and I am left here on the beach thinking about the people I used to work with who were military pilots, including several Vietnam veterans, an A6 pilot, an F-4 Marine pilot who was shot down and evaded capture despite the cracked vertebrae caused by his ejection, and another F-4 pilot who was just on the edge of being crazy, but was employed along with the rest of us as computer engineers and flight planning experts.

The guy who was shot down told me the story about it, he ordered his rear seat radar operator to eject, but there is some stigma about ejections, ejection is just not something any real aviator wants to do. So the RIO, or radar intercept officer, was reluctant to bail out first, which would have been safer, and when the pilot finally bailed them both out, the RIO was somehow killed. This is not that unusual, as it is generally fatal to eject from a 400 or 500 mile per hour or faster airplane, or to eject at higher than about 15,000 feet unless you have bottled oxygen and an electrically heated suit. Francis Gary Powers did not have anything like that, and supposedly above 25,000 feet you are going to black out for a while, just from rapid acceleration. You have to hope you come to before it is time to pull the ripcord. But whatever you do when ejecting the explosive ejection is going to break your back in at least one place, destroy a multi million dollar airplane, and is very likely to kill your RIO if it doesn't kill you both.

But my friend at worked bailed out, and evaded, and his crew man died. He looked me right in the eye when he told me this story, so there is no bullshit here - if they would have stayed they would have died, and it is not like there is any doubt as to whether ejection was the right thing to do.

Anyway the almost crazy F-4 Air Force pilot used to walk around the office talking about different aircraft, and fast cars or fast computers and stuff like that, and he always commented about whether something was a hummer or not. I took it that a hummer was an especially fast plane or car, or girl, and being a hummer seemed to me to mean that the sound barrier was involved. I wondered if maybe things hummed when you broke the sound barrier, or if they put some kind of oscillating device in the F-4 to make it hum, thinking that would make it easier for it to get past the sound barrier.

Years later I met a guy who flew test flights on the first F-4s for the Air Force, and he told me that he took his plane up to Mach 2.26, and as high as 70,000 feet, where it gets dark, and you can see electrical sprites. Well 2.26 is almost as fast as the Concorde can go, a plane that is a much different design than the F-4. Concorde's supersonic design is to F-4s, what the F-4 is to the Cessna, and what the Cessna is to Orville and WIlburs motorized glider. Its just a different design and the idea that a plane that was designed to be faster than Mach 1 could actually go over twice that fast is pretty amazing.

So it made me wonder a bit about what it meant to go Mach 1, and whether the plane actually started humming, and whether it might help reduce "sound friction" if the plane itself could be made to hum. An extension of that is the idea that maybe making the plane electrically charged might help repel air molecules - or something - and reduce drag in that way.

But I didn't know much about it, and then finally after many years I was semi-retired and reading in the library all the things I wished I had time to read when I was 20. It turned out there were some old ideas about slats and spoilers and suction and so on that related to delaying the separation of the boundary layer over the wing. Suction involved a vacuum pump that drew off the air from the top of the wing, sometimes using it as high pressure intake air for the turbines. There seemed to be a lot of confused ideas about it, except that about that time I was on a L-1011 that had holes in the slats, and holes was one way that the old-timers had tried to use to create suction and relieve the boundary layer.

When I worked with the Vietnam veterans I was so confused that I didn't have any questions, and now I was pretty clear on what it was that I did not know. I guess I had always had the questions, I just didn't know what they were yet, to quote one of my old engineering complex math professors.

What is really going on in the boundary layer that makes it such a good thing?
Would it help get past Mach 1 if you were vibrating?
What kinds of things are useful in delaying boundary layer separation?
What is happening after boundary layer separation and can I minimize it?
What is happening to the boundary layer above Mach 1?

It was not an obvious thing, the fact that at Mach 1 you no longer have any boundary layer. You are not born knowing this. There are some excellent diagrams in a paper by von Karman that show the Mach effect as a perspective of pilot's speed. These diagrams let you picture that flying close to Mach 1 is like flying into a tunnel of incompressible air.

Faster than Mach 1 you are past the air before it has time to compress or expand. There are no aerodynamic forces acting on the aircraft. In fact the aircraft is flying through a fluid that is no longer compressible, as if it were water. There are photographs of aircraft flying into a wall of water, or trailing a wall of water behind them. This is best explained by saying that the plane is moving too fast for the air molecules to move out of the way. They can't move, the only thing they can do is pass a sound, a sonic boom, like clapping your hand onto the water at the pool. When the aircraft moves through the air this fast the air molecules suddenly behave as though they were incompressible, and there are air temperature changes involved with becoming incompressible. If there is water vapor present it will all come out, squeezed out, creating the wall of water effect - the contrail.

Picture the air as a wet chain link fence composed of oxygen and nitrogen. A backstop at the ballpark is a good example. The first time the catcher runs back to field a foul ball he jumps up on the fence and all the water shakes off of it. The next time he runs back there the water is gone, he jumps up on the fence and no water comes off. It is the same with incompressible Mach 1 air. The first plane knocks the water out of the air, when the second plane flies through there is no water left.

There are three things that can happen to the water vapor after the first plane flies into it. It can create a fog that is suspended water molecules, it can create a rain or mist that falls down toward the ground, or it can re-evaporate.

As an aside, and as something to think about, let me point out Langmuir's conjecture that water never condenses unless it condenses on something solid. And when water does condense, it gives up its excess of energy in the form of both heat and kinetic energy, adding both heat and movement to the solid thing it condensed on. If anyone has any thoughts - like about how Mach 1 makes the air seem solid to the water molecule, or how condensation can lead to tornadoes, I would like to hear them.

Savannah

Savannah Georgia

Savannah is a really neat little town. There are two interesting aspects to this town from a city planning point of view, and of course the place has a lot of history. One of the historical aspects to the town is that after Cump Sherman besieged and conquered it at the end of "Sherman's March to the Sea", he gave all the land south of Savannah, all the way to Florida, to the Africans. There is some nice land in there, and a lot of really pretty coastal waters. If I am not mistaken John Kennedy Jr got married at one of those islands, and the great lacrosse and football player Jim Brown was born and raised back there.

From a city planning point of view, the interesting thing is that the town was never levelled as part of the 1960's "Urban Renewal" program. All of the houses and businesses are in old buildings dating back to the 1840's. The layout of larger homes include slave quarters, and the town itself was laid out with a large number of parks - every two blocks there is a park. This let in fresh air and sunlight back in the day when everyone burned wood for heat and cooking.

The other interesting thing is that the freeways end here - as originally envisioned by Eisenhower all freeways ended at city limits. They weren't supposed to go through, and one result of the change was that lots of inner city neighborhoods were gutted when freeways were built. Since the government wanted to save money freeways were generally built on inner city land that was the cheapest - the black neighborhoods. So the real result was that up until the 1960s there were a lot of long-established family owned businesses in central cities, and the freeways put an end to that.

When I was in school the example that was used was Knoxville, but today you can go to a lot of cities and find a re-development district near a freeway, and you can bet it used to be a street full of black owned businesses. If you cross under the freeway you will likely find a neighborhood that has always been populated by blacks. So much for the legacy of Cump Sherman!

I have been talking to a lot of people around here about heat, and what it means and how PV=kRT is just the observable thing about heat. And it is not wholly accurate, or else people wouldn't try to invent "wind chill" or "real feal" numbers by including other variables such as humidity and so on.

But one interesting thing came up when I was reading a book by Tim Kantor. Kantor's father was on B-17's and one observation that everyone made on B-17s was that smells propagated faster at altitude. Now once I sat down and computed that if air molecules were vibrating at (as I recall) 4x10^9 vibrations per second, and if the molecules were (I forget) about 400 Angstroms, then the speed of propagation of larger molecules, such as scent bearing oils, would be about 20 meters per second, or 44 miles per hour.

People tell you its a sixth sense when the pretty girl looks up just as you start to gaze at her, but it is not. Its pheromones, and it takes about half a second for your skin temperature to rise, releasing pheromones at 45 MPH, so that she notices you looking almost right away. Now the thing to do to test this is to try staring through windows, or try staring at a cute girl who is 50 meters away. I think you will find I am right about the 20 m/s.

But it is faster at altitude, and I am open to anyones suggestions about why. Speaking of altitude, in Savannah they have a great Army Air Force Museum which includes a display that talks about the missions that Joe Kennedy Jr flew and was killed in. The heroism of this family is a big contrast with the President's family. The Bush family includes Prescott Bush, famous for writing a wholly fictitious account of his heroism for the hometown paper, and George Sr, who is famous for jumping out of perfectly good airplanes, and George Jr who is famous for being absent.

Senator Kerry of course is famous for actually being in battle, and actually taking lead, and if you believe the papers, that makes him a coward. What's up is down. Can you tell a green field from a cold steel rail?

Everglades

Mitchell's Landing Florida

Mitchell's landing is a narrow spot at the end of the road where you can put an airboat or a canoe in. You can also register for a permit to camp in some cleared patches along the road. They have trash cans and two portable toilets, and a dozen circles of broken limestone if you want to pick one out for a fire pit. Its drained swamp and hammocks, with a canal running along the main road, full of fish. You ought to see the heron over in Mitchell's Landing.

I learned just a little bit about teaching once, some concept called building bridges and digging tunnels. Its all about building new knowledge on top of old and showing how things interconnect. I don't know much about lecturing, except that when I was in school there were some really bad examples, and one really good one - my electronics teacher gave a lecture that was absorbing and breathtaking, and you couldn't believe how he could write equations for 47 minutes without looking at notes.

I can't lecture like that but what I am good at is showing new ideas to one person, and telling if they are lost or not. The people I was working with asked me what I do when the person gets a glazed look in their eye and I said - "review" Then take a break. So here is a review of fluids, in about 200 words.

You already know what fluids are, things that flow. It can be a solid or a gas. Hundreds of years ago some good ideas about fluids were written down, someone named Dalton and someone named Boyle. There is a concept of perfect fluids - fluids where every atom behaves like every other one. And there is a concept of partial pressures, where in a mixed gas if the whole volume has a pressure, then each component gas, such as nitrogen or oxygen, also has that pressure. The last thing we know for sure about fluids is that temperature is a function of pressure and volume. PV=kRT where R is Boltzmann's constant.

Then quite a bit of time passed and Navier - the great mathematician, and Stokes - who explained fluorescence, independently came up with some calculus equations that described the state of a gas and how it changed. Navier Stokes is a big deal, and as far as math describing a system its hard to find anything more elegant, but I'm no expert in it. The short answer is Navier Stokes works and can make you a lot of money if you need something like it.

The long answer is different. The long answer says - well what is pressure, really - when we measure temperature what is it really we are measuring - what is involved in being a 'mixed gas' - how do partial pressures get to be the same - in what way is my gas different from ideal. The long answer is we don't really know, pressure and volume and temperature are the most easily observed things. We can observe the gas to have a value for those variables, we can observe how the gas behaves according to Navier-Stokes if we heat it up, and we can observe that for common air it is really hard to tell the difference between our gas and a 'perfect gas'

The variables of pressure volume and temperature are observable and they are also controllable. We can press the gas into a smaller space, or heat it up, or add more gas to change the variables. P V and T are at the same time observable and controllable. So it is safe to use the equations without worrying about the molecular shape of the nitrogen molecule, or the fact that water vapor has an ionic value - it's an electrical dipole, or worrying about the fact that oxygen is likely to combust with other molecules in an oxidation-reduction reaction. We don't need to worry about the fact that 'temperature' is mostly just a measurement of atomic vibrations, and we don't need to worry about the spinning energy of rotation of molecules because we can't observe that easily and we can't control it. We don't need to know. That's eight weeks worth of fluids lectures, without the homework.

Fluid dynamics is a little different. This is when you put fluids in motion and few hundred years ago some ideas were written down by Magnus and one of the Bernoulli's. These ideas are generalizations of more complicated things just like the Boyle Dalton and Navier-Stokes ideas. The generalizations are useful, and they usually work, but moving fluids are more complicated. In my opinion, Magnus and Bernoulli have led to generations of confusion in systems that involve dynamic fluid flow.

What Magnus said is that when a fluid passes over a rotating object it creates lift. What Bernoulli said is that when a fluid speeds up the pressure decreases, useful for creating lift on the top side of a wing. Both are right, and both are generalizations of what is really going on with the molecules in the fluid. In addition I think that both ideas are specific instances of the other man's ideas.

For Magnus the rotating object creates a relative difference in air speeds. One side of the disk speeds up the air, the other side slows it down. Thus you can apply Bernoulli to the relative changes in air speed in the Magnus rotating object. A Bernoulli wing is just a Magnus disk cut in half, and with an angular speed of zero. It might be nice to have a deformable rotating object so that we could spin it and still have it be flat on the bottom, and see what happens. That would be a good test of what Magnus says.

I think that what is really happening with 'lift' is something funny in the air that is not observable. Bernoulli says lift is related to velocity, and Prandtl wrote the equations that determine lift over a two dimensional line along the wing. But velocity is a vector, it has a direction and a magnitude, so it could be that Bernoulli should apply to air that changes direction but does not change speed. That would be a good test of what Bernoulli says.

There are two other basic ideas in fluid dynamics. One is the vortex, or the circulation of fluid that is created by a rotating cylinder. The other is the wake, or the chaotic flow that occurs downstream from an obstruction in the fluid flow. All the other ideas, such as boundary layer, laminar flow, wake vortex, von Karman Streets, modelling wings as if they were a pair or vortexes, Kutta-Joukouski transformations, streamlines, potentials and potential flows, all these ideas come from the basic ideas. The basic ideas are that there is a bow shock, there is a wake flow, vortexes occur naturally in the presence of magnetic fields, and air changes pressure when it changes speed or direction.

That's the review, and I'm glad I got it out of the way!

Key Biscayne

Key West is interesting for a little while and while I was there something happened that was right out of a Blake Edwards movie, so dreams do come true. It was nice. Since the last time I was there the place has gained and lost a reputation for boozing and drugs.

It used to be that no one who went there was just passing through, because there is nowhere farther to go. Jimmy Buffett and cruise ships changed all that. Now when the cruise ship hits the dock a thousand people come ashore and drink and shop like it was the Embarcardero in San Francisco. The whole north end of Duvall Street is shoulder to shoulder. Some of the other keys are kind of nice if they aren't too flat and don't have an RV Park. And John Mellencamp was recently sighted down there according to the paper. He did it right, is my guess.

Hunter Thompson killed himself a few days ago, he used to spend a lot of time in Key West. His writing is like the 60's, three layers of foliage and even if you could see through that, there is still no way to know if there is a tiger lurking underneath. They say he got the suicide from Hemingway who lived on Key West, but I think he probably had a terminal liver disease and wanted to end the pain.

Contrast Thompson with Ken Kesey's books. Kesey's early work is like a tour through the tropics at the garden club, and at the end they have a tiger that roars on command. I wanted to mention Kesey because of his "Merry Pranksters" book - which is about some people touring the country for no good reason, in the 1960s, when nobody did anything like that, and it was a suspicious thing to be doing.

Well anyway....Why is it that I think I ought to be writing about fluid dynamics. I went to engineering school and took a bunch of their classes but I didn't graduate. In fact I missed a few really basic classes in engineering. What I did instead was learn more math than any applied person ought to know, so if I can't read a fluids book to find out whats going on, then who can? Fluid dynamics is interesting, so my mind is made up.

After a lengthy college career I worked for a long time in computer software development, first as a technical writer, then for 4 years as a programmer, then for 5 years as a network engineer/tools/release expert, and finally working a few years in quality assurance. I met four really smart engineers, Jorge Wes Dave and Kersti, three really good managers, Eric Bryan and Tom, and a few other people with particularly outstanding skills like "getting things done in an organization - Stephanie", "teaching people how to get along - Woody", and "passing along knowledge to younger workers - Charlie" and "dreaming up something way ahead of its time - Steve". But one of the most interesting things I was exposed to was a story told to me one day by my uncle. My uncle Jim had started as a computer programmer way back in 1964, back in the day when for memory they used magnetic drums similar to ones in older analog Xerox machines.

Young Jim was the new kid on the block, all the other programmers had used the computer during the war, or had been involved in building the thing. So after a few days Jim got to go near the machine with an application that read the MICR magnetic encoding off of a stack of checks. He put the punch cards in the hopper and compiled the program, and he put the checks in the feeder. He told me he noticed people peeking at him while he did this. Then he pushed "Go" and the first check zipped along the runners and was routed correctly and then everything stopped. It turned out he forgot to allow for a mechanical delay in the mechanism that fed the checks. After the first check was read the computer forgot to wait for the next check to come by. It decided there were in fact, no more checks.

Putting in a delay for some mechanical operation is not an obvious thing to think of. You don't normally have to account for the fact that the computer is so much faster than the mechanical runners. Timing these kinds of things and getting used to the quirky nature of computer driven machinery led to the science of "systems" which is what I was supposed to learn in college.

I learned a lot about it, and years went by and I was talking to my Uncle again, and he exclaimed that I was talking about something he was familiar with. I was just talking about ways to eliminate wobble in car tires at high speeds, or how radios sometimes make squelching noises. I was talking about feedback and automatic control, and for me those were easy topics, but to technical people in my uncle's generation it was not something he really understood. He was familiar with some people who built a high pressure valve that was regulated with a rotating weight system. These kind of rotating governors were invented for use on steam engines, and they also made cotton gins practical. But my Uncle Jim's reaction told me that these things were a mystery to him, while for me I was familiar with all the quirky ways the governor could interact with the engine it was controlling. That is what systems is all about - the interactions between complicated things.

A lot of people will tell you systems is about viewing things like a black box, and measuring inputs-outputs, or drawing charts of flows, or measuring rates and levels. Those things are good tools but it might be that "interactions between complicated things" is the best definition of systems. In Jim's check processing example the interaction broke down because the computer was working in milliseconds and the check feeding mechanism was working in tenths of seconds. There needed to be synchronization, and Jim accomplished this by making the computer wait a fixed amount of time. This isn't "synchronization" but it solved the problem by making sure the check was waiting there before the computer looked for it. It could be foreseen that maybe there is a case where two checks are waiting, but thats another lecture!

Now step back and see if there is another way to look at the system Uncle Jim was in. There was also interaction between people and the computer. Not much can happen between the one person reading in the deck of punch cards and stacking the checks. But the part of the system that Jim was really excited about was the interaction between the veterans and the college guy, with respect to using the computer. Likely the veterans felt threatened by the college kid, just as the college kid felt judged by the veterans. But what happened was good for everybody. When the computer-check reader failed the veterans felt vindicated - "there is no substitute for experience" And the college kid's failure made him a member of the group - "you can only learn by making mistakes" This is what systems is all about - the interactions between complicated things!

Now what does this have to do with fluid dynamics? Well not much really. A few years ago I listened to the audio tape of John Glenn's book The most interesting thing to me were two or three stories he told about being a test pilot. In one of the stories they were working on a new jet, say the F-86, and there was a problem with the machine guns overheating. Someone designed a heat sink to put on the barrels and when Glenn tested the guns they no longer got hot, but the leading edge aerodynamics changed dramatically. A resonance was created when he fired the guns, causing a rippling wave to go through the wing. The wingtip was whipped about when the wave reached it, causing what is called PFOA - parts falling off the airplane. This was a life-threatening interaction between a well designed wing and some add-on hardware that was never tested in the wind-tunnel. The best solution turned out to be synchronizing the guns so they did not fire in order. No regular firing order, no wave, no PFOA.

Another Glenn example had to do with the air intakes for jet engines at high sub-sonic speeds. This is a tough math problem, and in the early 1950s there were no computers good enough to solve it. Some of these planes would fly along and as soon as you turned or dove, the airflow into the engine would choke off and the engine would stop. Another example is in the 1970's they added wing tip fuel tanks to the B-52. One day they found out that at a certain rate of descent the new fuel tanks caused flutter in the wings that could resonate and shake the wing apart. Until they developed a new spoiler that could dampen the flutter they had to live with the dangerous wing. Pilots could easily stop the flutter by pulling up out of the descent, but they only had about ten seconds to do this once the flutter started. Having a man-machine system that requires human input at least every ten seconds is a dangerous thing. People get fatigued, they get distracted, they get bored. This system required constant vigilance which is stressful for human beings.

So with John Glenn's machine gun problem the solution was to test fire the guns and make sure they didn't fire in order. With the engine intake problem the best solution was to redesign the intake. For the B-52 wing tanks they temporarily required the pilot to be careful during descent, and the permanent fix was a new spoiler that dampened the flutter.

All these things illustrate that fluid dynamics as applied to airplanes is not well understood. Things seem to fail when you least expect it, and over-confidence is not a good thing to have. One of the stories that came out of Edwards test pilots is that the pilots did not trust the new hardware to fly safely. If someone had made an ad-hoc fix to the plane using duct tape, then it was probably safe to fly. The way I heard the story is they always used green duct tape at Edwards, to tape down an access panel that was a little loose, or to close off a seam in some faulty slat design, or to hold a hydraulic line in place on the cockpit floor. If it didn't have any green tape on it, it wasn't ready to fly.

Anyway, the whole conversation with my uncle led me to conclude that the stuff I knew was not obvious to everyone, and most people took it for granted. For example most people would not realize that there were two systems involved in the check processing application - 1) the new programmer interacting with the computer, and 2) the group of computer programmers interacting with the new guy about passing along computer knowledge. Since its not obvious, I thought it might be a good idea to write some of these ideas about systems down, and that's why Im writing this blog. The fluid mechanics is a good place to start, since that has been on my mind for awhile, and is fresh in my mind.

And if you get a chance, stop by Wal-Mart. And for Edwards sake, get some green duct tape. It will make me feel a whole lot better if you do.

Key West

Blogs are neat I guess. I have wanted to write one since I started out on the road. I wanted to write a log of my travels and what I was thinking about or doing while I was on the road. There have been some impressive similar things in my lifetime, like Charles Kuralt's journals of his travels across America for CBS in the 1960's and 1970's. Kuralt was an interesting American like other TV journalists, including Chet Huntley whose life was a lot like the movie "A River Runs Through It" Bob Schieffer is also a good example of a hard working serious journalist whose life was not ruined by notoriety.

Another example of pre-Internet travel logs is "Zen and the Art of Motorcycle Maintenance" In that one the scenery runs together so much that all you really get is a course in freshman level philosophy. And because I am an engineer at heart it seems to me that that interesting book is really just a lot of hoo-ah. Robert Piersig is an interesting writer though, and if you have trouble sleeping, then his captivating book will cure your insomnia for about a month.

Because I am travelling in the twenty-ohs, one title I considered for this blog is "33 Walton Drive". People travelling nowadays spend a lot of time in Wal-Mart parking lots, and also public rest stops along the highway. If you think about it, I can spend about sixteen dollars for a spot in a campground, or I can buy 8 gallons of gas and drive 150 miles, if I stay at 33 Walton Drive. The campground includes a hot shower usually, and that is an essential for travellers. I am in a van that I fixed up myself, and it does not include a shower stall.

Anyway I decided not to call it 33 Walton Road, because Wal-Mart is not the focus of my blog. I did, today, enter recent expenses into Quicken and found that 35% of my recent expenses were at various Wal-Marts. Most people don't realize that there are only about 4 or 5 different floor plans for Wal-Marts, so that for people like me, I can go into the store in the morning and find what I need - ketchup and other condiments are in aisle 8 - most types of Wal-Mart have a restroom in the back that is cleaner and quieter than the one if the front.

I hope I don't do a lot of writing about Wal-Mart. What I want to write about is, mostly, what I think about things, mainly engineering things, and some thoughts about the ones I think are important and should not be forgotten. This is stuff they don't cover in undergraduate engineering, and I get the feeling that most engineering professors of graduate students are too busy with their research contracts to gaze at the stars and realize all the gaps in our knowledge. For example about 4 years ago a physicist retired from Lawrence Livermore and spent a few years writing a book about starlight, and filling in some of the gaps in our knowledge about starshine. Starshine and twinkling aren't crucial, we didn't need to know about it to get to the moon, but I'm glad that he took the time to write that book, in case anybody ever wonders. The knowledge he had about starshine will not be forgotten.

So I'm going to write about engineering problems, mainly. If you want to know what I think abouit the progress of science or computers you might look on Lawrence Lessig's blog for some comments I put on there. And if its political you might just get some email from me, or email that I wrote and mass-mailed around. I started my emails about 1999, when I took my first long trip, and its interesting because although media people picked up some of my ideas starting back in 1999, the media won't comment on them. Private messages are not news, but what people write in public places is news, and the media comments on it.

This is the nature of the new network: There is a private level of email, a public level of blogs and newsgroup messages written by individuals, and thirdly there is a public level of commercially produced news sites that feature RSS (XML) for those who want custom news. All these together remind me of an old science fiction story where the news was downloaded over radio waves. Everyone had a two-sided piece of plastic to take on the bus with them. The plastic was filled with formatted text and as they read one side, information for the other side was downloaded and composed onto the back page according to their specific instructions. You could do this today with HTML, RSS and a cell phone. All you need is a monitor that is somewhat paper like, and can be folded up and put under your arm.

So if you don't want to learn about engineering problems, then don't RSS my blog. Just put it away or use it to cover your head during a rainstorm. But if you have some engineering and have forgotten it all, there isn't a lot of time to do refresher courses, and I'm not qualified to teach it accurately. I am a good teacher though, and if you are patient you might see some new ideas, or ideas that will make you say "Sure that is obvious" even though no one you know ever mentioned it before. I will start tomorrow, in Key West, which is where my trip will begin, even though, like I say, I have been living at 33 Walton Drive for over seven months now. The first topic will be fluid mechanics.