Hot August night
And the leaves hanging down
And the grass on the ground smelling sweet
Move up the road
To the outside of town
And the sound of that good gospel beat
Sits a ragged tent
Where there ain't no trees
And that gospel group
Telling you and me
It's Love
Brother Love's Traveling Salvation Show
Pack up the babies
Grab the old ladies
Everyone goes
Everyone knows
Brother Love's show
--Neil Diamond, "Brother Love's Traveling Salvation Show"
The Congressional Record contains many interesting items, especially from the days when a filibuster actually required Senators to continue speaking for the duration. Often a filibustering Senator would read from a book, insert cooking recipes, and the like, just in order to keep the words flowing. Nowadays, not only is this not required, owing to a thing called Senate Rule 22, which allows some Senators to say "we're filibustering," and then a cloture vote determines whether or not the bill is blocked.
It's also quite possible for things to show up in the Congressional Record that were never actually said on the floors of Congress, and things that are said may be taken back, the CR being amended to nullify the past, and isn't that the way it ought to be with everything?
I doubt that my name was ever said in the Hallowed Halls, but it does appear in the Congressional Record at least once, as a citation of an EPA report in the background documentation for some air quality legislation (you'd think I could be more specific, and I probably could, but there are limits to how much work I'm willing to put into these little memoirs). It was, as I recall, a monthly report that later went into a document sometimes cited as just "Killus et al." (heh, heh), primarily because I was co-author to a majority of the individual chapters. The final publication was titled "Continued research in mesoscale air pollution simulation modeling. Volume 5: Refinements in numerical analysis, transport, chemistry, and pollutant removal" [Final Report, Oct. 1979 - Jul. 1982] KILLUS, J P; MEYER, J P; DURRAN, G E; ANDERSON, G E; JERSKEY, T N.
The full report included new transport algorithms, chemistry, actinic flux calculations, aerosol formation mechanisms, and surface uptake models for a photochemical grid model. The subsection that went into the CR was on the surface uptake mechanisms, i.e. the way that pollutants are absorbed or otherwise destroyed or transformed by interactions with surfaces, and I co-wrote it with the last guy cited, Terry N. Jerskey.
We didn't really work that closely together, having broken up the problem into piece parts with Terry doing some chunks of it, and me the rest. But there was a fair amount of time sitting across the table from each other, talking about this or that aspect of things like surface resistance, diffusional transport in the planetary boundary layer and other nurdy things that we were being paid to talk about. It was a lot of fun, actually, for me at least. I hope Terry enjoyed it.
Terry's hands shook by that point, a tremor that was a side effect of the medication he was on, I think it was Haldol, but this is a 30 year old memory here, and he only told me once.
One day, late, after everyone else had left the office except Tom, who was a chronic workaholic, Terry went over to the shopping center across the street and bought several bottles of dry cleaning fluid, which he proceeded to swig down on the way back to the office, tossing the bottles into the trash cans on the way back. He made it back to the office and collapsed on the hall floor, where Tom found him a few minutes later.
In addition to being a workaholic, Tom was also a member of the Ski Patrol, and strong as an ox besides. Both turned out to be important, because, after he called for the paramedics, he had to use that strength to pry Terry's jaws apart, in order to give him mouth-to-mouth respiration. Terry's jaws had become locked with muscle spasms, you see.
Then, after the ambulance arrived, Tom raced across the street and located the bottles of cleaning fluid (which I suspect he'd tasted in Terry's vomit and breath during the time he was doing Terry's breathing for him) and reported what Terry had swallowed to the ER by the time Terry had arrived.
This wasn't Terry's first suicide attempt, it turned out. That was the reason for the anti-depressants. In fact, I heard that Terry's wife was pretty blasé about the matter when she was called.
The next day, Terry was sitting up in the ICU, alert, seemingly fine. He told everyone who visited that he'd be back at work pretty soon.
The next day he was dead. The cause of death was "aspirated pneumonia." Vomiting cleaning fluid and then breathing it into your lungs causes damage, and there was enough damage for entirely different fluids to build up in his lungs—enough to kill him, in fact.
The only thing that I ever learned about Terry other than our working together was that he loved Neil Diamond, even the later pretentious stuff like "Longfellow Serenade." When we spoke about Neil, I'd always talk about songs like "Brother Love's Traveling Salvation Show," because I could honestly say that I liked it.
I honestly liked Terry, too, but not nearly enough, really. For the most part, he was just a guy I worked with for a while.
Wednesday, February 13, 2008
Tuesday, February 12, 2008
It's Always about the Blood
It's always about the blood. – Spike, from Buffy the Vampire Slayer
Bone marrow makes blood cells. More specifically, it contains various "uncommitted" stem cells that remain in the marrow while splitting off cells that then are "committed" to maturing into cells that circulate in the blood.
The biggie is the red blood cells, without which you and I would die in seconds, since they are what convey oxygen from the lungs to everywhere else. The fancy term for red blood cells is erythrocytes, which has the interesting characteristic of being not only less informative than "red blood cells" but also has more syllables.
The lab measurement for red blood cells is called "hematocrit," and 35% to 55% is considered normal. Less, and you have anemia. More, and you may have a blood disease, live at a high altitude, have dengue fever, or are taking a performance enhancing drug, like EPO.
White blood cells are "leukocytes," or ""lymphocytes" (hooray! same number of syllables, plus there's a differentiation in kind. That's what technical terms should be about). There's an entire menagerie of white blood cells, having to do with which part of the immune system is in play.
Then there are platelets, aka thrombocytes, which aren't exactly cells, but I'll get to that. A normal platelet count is between 150,000 and 400,000 per cubic millimeter of blood, but the ",000" is usually dropped in reporting, so a person with a platelet count of 200,000 is usually said to have a platelet count of 200. A low platelet count is called thrombocytopenia, and may create problems with bruising, bleeding, etc. although there are other factors involved. A count of 120, for example, is not considered that big a deal, but if the count drops below 20, the risk of spontaneous bleeding becomes very high.
Platelets aren't cells, per se; they are more akin to cell walls, hence the "plate" part of the name. Platelets are formed in the cytoplasm of a very large cell, the megakaryocyte. Megakaryocytes mature in about 10 days, from a large stem cell, the megakaryoblast. The cytoplasm of the megakaryocyte fragments at the edge of the cell. This is called platelet budding. The spleen serves as a holding tank for platelets, and contains about a third of the blood's platelets at any given time. Platelets are destroyed by macrophages, and have a lifetime of between 8 and 12 days in the blood, so the full life cycle of a platelet is on the order of about 20 days.
Platelets are necessary but not sufficient for blood clotting. A blood clot consists of a mass of platelets enmeshed in a lattice of insoluble fibrin molecules. Platelet aggregation and fibrin formation both require the proteolytic enzyme thrombin, plus calcium ions and about a dozen other protein clotting factors. Most of these circulate in the blood as inactive precursors until they are activated by trigger enzymes that form when blood vessels are ruptured or something else unpleasant happens.
So, basically, platelets are the bricks and the aggregation factors are the mortar, glue, etc, that hold them together to form blood clots. This entire process is pretty much unique to mammals, incidentally.
There are a number of drugs that will reduce platelet count, including the aspirin-like drugs, ibuprofen and naproxen. I was taking prescription-level amounts of naproxen until recently, owing to the practice of Aikido, and this did lower my platelet levels to somewhat below the lower level of normal, which is to say 100-150, but I did not seem to have any clotting problems, so big deal, was my opinion. However, a few months ago, I began a series of encounters with a fine (intentional irony here) drug called Temodar, which really slams the platelet count, so I had to give up the naproxen. I now report that this made me feel roughly 10-15 years older on the Aikido mat.
A fellow Aikido student recently underwent a root planing, a dental procedure that removes accumulated plaque from below the gum line. After finishing one side, the dentists said, "There's too much bleeding here. I'm not going to do the other side without a doctor's release." So, said student went to his doctor, who sent him to get the requisite blood test.
Upon receipt of the results, the doctor called and told him, "I want you to immediately go to the nearest hospital and check yourself in." The student then called a friend of his, also a physician, for advice. Upon reading his friend the blood test results over the phone, the friend said, "What are you doing talking to me? Go to the nearest hospital and check yourself in immediately."
Our boy did not quite follow the advice. He first wrote up a list of things that needed doing at his job, then he went, not to the nearest hospital, but to San Francisco General. This was actually a good move, because they immediately sent him over to UCSF Hospital, where they could make a proper diagnosis, and where he is now just about done with the chemotherapy for the rare (and, fingers crossed for the happy ending) and very curable form of leukemia that he had developed. Upon admission, he was immediately given a transfusion, and has since had 6-8 "platelet packs," which consist of platelets that have been centrifuged out of whole blood.
He is 36.
His blood test platelet count was 11.
Bone marrow makes blood cells. More specifically, it contains various "uncommitted" stem cells that remain in the marrow while splitting off cells that then are "committed" to maturing into cells that circulate in the blood.
The biggie is the red blood cells, without which you and I would die in seconds, since they are what convey oxygen from the lungs to everywhere else. The fancy term for red blood cells is erythrocytes, which has the interesting characteristic of being not only less informative than "red blood cells" but also has more syllables.
The lab measurement for red blood cells is called "hematocrit," and 35% to 55% is considered normal. Less, and you have anemia. More, and you may have a blood disease, live at a high altitude, have dengue fever, or are taking a performance enhancing drug, like EPO.
White blood cells are "leukocytes," or ""lymphocytes" (hooray! same number of syllables, plus there's a differentiation in kind. That's what technical terms should be about). There's an entire menagerie of white blood cells, having to do with which part of the immune system is in play.
Then there are platelets, aka thrombocytes, which aren't exactly cells, but I'll get to that. A normal platelet count is between 150,000 and 400,000 per cubic millimeter of blood, but the ",000" is usually dropped in reporting, so a person with a platelet count of 200,000 is usually said to have a platelet count of 200. A low platelet count is called thrombocytopenia, and may create problems with bruising, bleeding, etc. although there are other factors involved. A count of 120, for example, is not considered that big a deal, but if the count drops below 20, the risk of spontaneous bleeding becomes very high.
Platelets aren't cells, per se; they are more akin to cell walls, hence the "plate" part of the name. Platelets are formed in the cytoplasm of a very large cell, the megakaryocyte. Megakaryocytes mature in about 10 days, from a large stem cell, the megakaryoblast. The cytoplasm of the megakaryocyte fragments at the edge of the cell. This is called platelet budding. The spleen serves as a holding tank for platelets, and contains about a third of the blood's platelets at any given time. Platelets are destroyed by macrophages, and have a lifetime of between 8 and 12 days in the blood, so the full life cycle of a platelet is on the order of about 20 days.
Platelets are necessary but not sufficient for blood clotting. A blood clot consists of a mass of platelets enmeshed in a lattice of insoluble fibrin molecules. Platelet aggregation and fibrin formation both require the proteolytic enzyme thrombin, plus calcium ions and about a dozen other protein clotting factors. Most of these circulate in the blood as inactive precursors until they are activated by trigger enzymes that form when blood vessels are ruptured or something else unpleasant happens.
So, basically, platelets are the bricks and the aggregation factors are the mortar, glue, etc, that hold them together to form blood clots. This entire process is pretty much unique to mammals, incidentally.
There are a number of drugs that will reduce platelet count, including the aspirin-like drugs, ibuprofen and naproxen. I was taking prescription-level amounts of naproxen until recently, owing to the practice of Aikido, and this did lower my platelet levels to somewhat below the lower level of normal, which is to say 100-150, but I did not seem to have any clotting problems, so big deal, was my opinion. However, a few months ago, I began a series of encounters with a fine (intentional irony here) drug called Temodar, which really slams the platelet count, so I had to give up the naproxen. I now report that this made me feel roughly 10-15 years older on the Aikido mat.
A fellow Aikido student recently underwent a root planing, a dental procedure that removes accumulated plaque from below the gum line. After finishing one side, the dentists said, "There's too much bleeding here. I'm not going to do the other side without a doctor's release." So, said student went to his doctor, who sent him to get the requisite blood test.
Upon receipt of the results, the doctor called and told him, "I want you to immediately go to the nearest hospital and check yourself in." The student then called a friend of his, also a physician, for advice. Upon reading his friend the blood test results over the phone, the friend said, "What are you doing talking to me? Go to the nearest hospital and check yourself in immediately."
Our boy did not quite follow the advice. He first wrote up a list of things that needed doing at his job, then he went, not to the nearest hospital, but to San Francisco General. This was actually a good move, because they immediately sent him over to UCSF Hospital, where they could make a proper diagnosis, and where he is now just about done with the chemotherapy for the rare (and, fingers crossed for the happy ending) and very curable form of leukemia that he had developed. Upon admission, he was immediately given a transfusion, and has since had 6-8 "platelet packs," which consist of platelets that have been centrifuged out of whole blood.
He is 36.
His blood test platelet count was 11.
Observing
You can observe a lot by just watching. [alternate version: You can see a lot by just observing.] –Yogi Berra
When I was seven, we had a siamese cat. Actually, it was a kitten; the little idiot never made to cat-hood. First he nearly drowned in the toilet, then he took to hiding atop the tire in the wheel well of the family automobile, to predictable results.
[In the previous paragraph, I’m engaging in either “blaming the victim,” which is usually thought of as a product of “identification with the aggressor,” or “reaction formation,” the covering of one emotion—sadness at the loss of a pet—with its opposite, or near opposite, in this case disdain. If I were to say that the kitten would be long dead in any case, given the life span of cats, I’d be “rationalizing.” Spending this much time analyzing my own reactions is an example of “intellectualizing.”]
In any case, one of the bonding events with the kitten was mediated though annoyance: he would jump up on my bed very early in the morning, like 4 or 5 A.M. and knead my chest while mewing to wake me up. It couldn’t have been hunger, because I didn’t feed him. Maybe he was just lonely.
One morning when he’d awakened me this way, I was intrigued by a pretty spectacular spectrum display on my bedroom wall. I investigated and it turned out that a shaft of light from the morning sun had gone through my aquarium before it hit the wall. The aquarium had acted like a prism, one with an internal reflection, in fact. Later I got some “pop sci” books on light and optics and read up on the subject.
Many years later, while flying home from college, I noticed some color on the cover of the book I was reading, which caught my attention because the cover was black-and-white. I knew that surface reflection of light is usually polarized, so I got out my Polaroid sunglasses and looked at the window of the plane. Sure enough, it showed spectral splitting of light, and the pattern looked like it was a strain pattern. A bit of reading later further informed me that looking at plastic strain via polarized light is an industrial testing procedure to check for defects in the plastic. The plane’s window pattern had been nice and symmetric.
I took further advantage of the sunglasses trick once when I was down in Los Angeles with my then housemate, Steve and some of his friends. Driving on 101, I noticed that the San Fernando Convergence Zone was clearly visible that day. The SFCV results when air blowing in from Los Angeles meets air coming from the other direction from Ventura County. Such convergence zones are common features of air flow near mountains, in this case the Santa Monica mountains.
Because the air from LA is more polluted than the air from Ventura, the SFCV has a clear demarcation, and it pushes air up above the nominal inversion height. I pointed it out to my companions, but several of them had to look at it through the polarized filter in order to see it. Polarization helps identify polluted air masses, because the fine particles exhibit surface scattering (Mie scattering) that is polarized. One of the people in the car said, “You know, I’ve lived almost my entire life in LA and I’ve never noticed that before.”
A while back, in the dressing room of Eastshore Aikikai, I noticed a circular spot of light on the floor. What caught my eye was the precision of the circularity. I looked up to the roof and spotted a small hole in a fan covering, and I realized that we actually had a pinhole camera in operation, a camera obscura. The reason why the light was perfectly circular was that it was an image of the sun. I’ve studied it since then and on partly cloudy days you can see the clouds move across the face of the sun. I suspect that if we had a better surface—smoother, whiter—it might be possible to make out sunspots.
Judging from its rate of travel across the floor, the camera obscura only operates for at most an hour a day, and I suspect it only does so for a few weeks or months per year. We'd only recently began classes in the middle of the day, and only one day a week, Sunday. So it’s not surprising that no one has noticed it in the year we’ve been there.
The other variable is having someone there who might pay attention to a spot of light on the floor, and wonder why it was so round. I have no idea of the odds on that, other than to suspect that they’re not very high.
When I was seven, we had a siamese cat. Actually, it was a kitten; the little idiot never made to cat-hood. First he nearly drowned in the toilet, then he took to hiding atop the tire in the wheel well of the family automobile, to predictable results.
[In the previous paragraph, I’m engaging in either “blaming the victim,” which is usually thought of as a product of “identification with the aggressor,” or “reaction formation,” the covering of one emotion—sadness at the loss of a pet—with its opposite, or near opposite, in this case disdain. If I were to say that the kitten would be long dead in any case, given the life span of cats, I’d be “rationalizing.” Spending this much time analyzing my own reactions is an example of “intellectualizing.”]
In any case, one of the bonding events with the kitten was mediated though annoyance: he would jump up on my bed very early in the morning, like 4 or 5 A.M. and knead my chest while mewing to wake me up. It couldn’t have been hunger, because I didn’t feed him. Maybe he was just lonely.
One morning when he’d awakened me this way, I was intrigued by a pretty spectacular spectrum display on my bedroom wall. I investigated and it turned out that a shaft of light from the morning sun had gone through my aquarium before it hit the wall. The aquarium had acted like a prism, one with an internal reflection, in fact. Later I got some “pop sci” books on light and optics and read up on the subject.
Many years later, while flying home from college, I noticed some color on the cover of the book I was reading, which caught my attention because the cover was black-and-white. I knew that surface reflection of light is usually polarized, so I got out my Polaroid sunglasses and looked at the window of the plane. Sure enough, it showed spectral splitting of light, and the pattern looked like it was a strain pattern. A bit of reading later further informed me that looking at plastic strain via polarized light is an industrial testing procedure to check for defects in the plastic. The plane’s window pattern had been nice and symmetric.
I took further advantage of the sunglasses trick once when I was down in Los Angeles with my then housemate, Steve and some of his friends. Driving on 101, I noticed that the San Fernando Convergence Zone was clearly visible that day. The SFCV results when air blowing in from Los Angeles meets air coming from the other direction from Ventura County. Such convergence zones are common features of air flow near mountains, in this case the Santa Monica mountains.
Because the air from LA is more polluted than the air from Ventura, the SFCV has a clear demarcation, and it pushes air up above the nominal inversion height. I pointed it out to my companions, but several of them had to look at it through the polarized filter in order to see it. Polarization helps identify polluted air masses, because the fine particles exhibit surface scattering (Mie scattering) that is polarized. One of the people in the car said, “You know, I’ve lived almost my entire life in LA and I’ve never noticed that before.”
A while back, in the dressing room of Eastshore Aikikai, I noticed a circular spot of light on the floor. What caught my eye was the precision of the circularity. I looked up to the roof and spotted a small hole in a fan covering, and I realized that we actually had a pinhole camera in operation, a camera obscura. The reason why the light was perfectly circular was that it was an image of the sun. I’ve studied it since then and on partly cloudy days you can see the clouds move across the face of the sun. I suspect that if we had a better surface—smoother, whiter—it might be possible to make out sunspots.
Judging from its rate of travel across the floor, the camera obscura only operates for at most an hour a day, and I suspect it only does so for a few weeks or months per year. We'd only recently began classes in the middle of the day, and only one day a week, Sunday. So it’s not surprising that no one has noticed it in the year we’ve been there.
The other variable is having someone there who might pay attention to a spot of light on the floor, and wonder why it was so round. I have no idea of the odds on that, other than to suspect that they’re not very high.
Sunday, February 10, 2008
Faster
I vaguely remember reading an anecdote once where Edison gave a newspaper reporter a list of things that every scientist should know. I don't remember the whole list, but one of them was the speed of sound in air. Another reporter showed the list to Einstein, who confessed to having no idea how fast sound propagated through air.
Edison, being partly deaf, was somewhat more interested in sound than Einstein, who was more of a light man, as it were. Still the speed of sound, as a principle, is mighty important; it just varies with a lot of things that were, to be fair, of interest to Einstein as well.
Sound propagates when atoms bump into each other, so it's important how fast the atoms can go, and the nature of the bumping. In solids and liquids, where molecules are sitting right next to each other, as it were, the forces between them, the elastic modulus is the critical factor, as is the nature of the wave that is being transmitted. Molecular movement in solids is also quantized, with the pseudo-particle being the phonon, which represents the quantum levels of forces transmitted from one molecule to another.
The speed of sound (SOS) in gases depends on how fast the individual molecules of the gas are moving, since any individual particle must actually traverse the distance between it and the next particle for momentum to be transferred. So there we get into all sorts of cool things like ideal gas laws, heat capacities, and statistical mechanics, some of which Einstein did have in his thoughts.
In the simplest approximations, the speed of sound for a gas is determined by two factors, the molecular weight of the gas and its temperature. The speed of sound is always limited by the RMS (root mean squared) molecular speed; the two are related via a fairly simple relationship:
RMS/SOS = Sqrt(3/BM)
where BM is the bulk modulus of the gas, it's resistance to pressure. For a diatomic gas, the bulk modulus is 1.4, so the ratio of RMS to SOS is about 3/2.
In rockets, the oomph that any given propellant will give is limited by the velocity of the exhaust gases. So basically you want your exhaust to be very hot, with the lightest molecular weight you can manage. In Rocket Ship Galileo, Heinlein had his protagonists use zinc as the propellant (heated via nuclear reactor), and has one of them muse that he'd have preferred to use mercury. This is, of course, almost exactly backwards, and Heinlein did a better job later, in, for example, Space Cadet, where "monoatomic hydrogen" is supposedly used.
Monoatomic hydrogen would indeed be a good rocket propellant, pretty much the best possible, if you could use it. However, the temperature at which diatomic hydrogen (which is to say, hydrogen gas) dissociates into atomic hydrogen is mighty high, in the thousands of Kelvin, and would probably destroy any rocket nozzle that could ever be built. As I recall, Heinlein had tanks of monoatomic hydrogen on his ships, no doubt made out of unobtainium metal, with a bolonium catalyst to keep the hydrogen atoms from recombining.
Rockets are, as I've said before, a horribly inefficient method of travel, since conservation of momentum means that you're hurling huge masses of material out the back end, and it�s taking most of your energy supply with it. In fact, the more "efficient" your rocket in terms of payload to fuel ratio, the higher the percentage of your energy supply is going into your exhaust stream.
Also, with chemical reactions as your energy source, you can't really use hydrogen as your exhaust gas, because it isn�t the product gas of the energetic reactions you'd like to use, always assuming that you don't actually have tanks of monoatomic hydrogen lying around. MH would produce some pretty hot molecular hydrogen when it recombined, so that would work. Too bad about the world wide unobtainium shortage.
All the speed of sound issues apply to explosively driven projectiles, aka "guns," as well, though such projectiles are much more efficient than rockets, energetically speaking. Mass drivers of all sorts have the advantage of using the Earth as a big momentum sink, and when you use something that large to absorb the recoil, it doesn't get much of the energy in the bargain.
You can't generally use hydrogen and liquid oxygen in a bullet (though there are some cannon designs that do), so typical muzzle velocities are limited by the average mass of the molecules in gases like nitrogen and carbon dioxide. Those have greater masses and hence lower particle velocities than does water vapor, to say nothing of hydrogen.
But then we come to gas guns, where the projectile is driven by compressed gas. Sure, you usually can't get the pressures in a compressed gas cylinder as high as you get from an explosive, but you can then use hydrogen, or helium as the gas. Helium, being honestly monoatomic, has only twice the mass of a hydrogen molecule, so its RMS and speed of sound is still pretty fast, which is why you get a high pitched voice if you inhale helium.
If you use a compressed gas cylinder, you have what is called a "single stage gas gun," which rather demands an answer to what a "two stage gas gun" is, right? Ah, there it gets interesting. In a two stage gas gun, you use an explosively driven piston to ram the gas into the compression chamber. Then, when it reaches a nice, high pressure (and remember, it's also been heated via compression), it ruptures a perforated valve and slams into the projectile, which is then propelled out of the barrel of the gun. Some designs preheat the original gas as well; you can exceed the melt temperatures for parts of the device for brief periods of time, and gun shots are nothing if not brief.
Lawrence Livermore Laboratory has a nice two stage gas gun that can propel a projectile weighing 5 kilograms to 3 kilometers per second. There were plans in the early 1990s, to upgrade the thing and to use lower weight projectiles, which would reach 8 kilometers per second, and LLL wanted to try putting things into orbit with it. Instead, absent the $1 billion upgrade, they had to content themselves with firing the thing into a liquid hydrogen target, experimentally demonstrating the existence of the previously only theoretical metallic phase of hydrogen. And even without quite so lavish funding, they do seem to have managed to get up to the 8 km/sec range, albeit with pretty light projectiles.
Theory doesn�t quite run out of oomph at 8 km/sec, however. As you go to higher and higher temperatures in hydrogen, you begin to get molecular dissociation. Heat your original gas hot enough, and compress it enough, and you can get a gas containing significant amounts of--wait for it--monoatomic hydrogen. I've seen a design document from The Rand Corporation on how to build one of those, and its theoretical top projectile velocity exceeds 10 km/sec. That's flirting with escape velocity and it's well over orbital velocity. It may also be getting close to the velocity necessary to compress inertial fusion materials to the point where a tritium-deuterium burn can occur, but that's a different essay, for another time.
Edison, being partly deaf, was somewhat more interested in sound than Einstein, who was more of a light man, as it were. Still the speed of sound, as a principle, is mighty important; it just varies with a lot of things that were, to be fair, of interest to Einstein as well.
Sound propagates when atoms bump into each other, so it's important how fast the atoms can go, and the nature of the bumping. In solids and liquids, where molecules are sitting right next to each other, as it were, the forces between them, the elastic modulus is the critical factor, as is the nature of the wave that is being transmitted. Molecular movement in solids is also quantized, with the pseudo-particle being the phonon, which represents the quantum levels of forces transmitted from one molecule to another.
The speed of sound (SOS) in gases depends on how fast the individual molecules of the gas are moving, since any individual particle must actually traverse the distance between it and the next particle for momentum to be transferred. So there we get into all sorts of cool things like ideal gas laws, heat capacities, and statistical mechanics, some of which Einstein did have in his thoughts.
In the simplest approximations, the speed of sound for a gas is determined by two factors, the molecular weight of the gas and its temperature. The speed of sound is always limited by the RMS (root mean squared) molecular speed; the two are related via a fairly simple relationship:
RMS/SOS = Sqrt(3/BM)
where BM is the bulk modulus of the gas, it's resistance to pressure. For a diatomic gas, the bulk modulus is 1.4, so the ratio of RMS to SOS is about 3/2.
In rockets, the oomph that any given propellant will give is limited by the velocity of the exhaust gases. So basically you want your exhaust to be very hot, with the lightest molecular weight you can manage. In Rocket Ship Galileo, Heinlein had his protagonists use zinc as the propellant (heated via nuclear reactor), and has one of them muse that he'd have preferred to use mercury. This is, of course, almost exactly backwards, and Heinlein did a better job later, in, for example, Space Cadet, where "monoatomic hydrogen" is supposedly used.
Monoatomic hydrogen would indeed be a good rocket propellant, pretty much the best possible, if you could use it. However, the temperature at which diatomic hydrogen (which is to say, hydrogen gas) dissociates into atomic hydrogen is mighty high, in the thousands of Kelvin, and would probably destroy any rocket nozzle that could ever be built. As I recall, Heinlein had tanks of monoatomic hydrogen on his ships, no doubt made out of unobtainium metal, with a bolonium catalyst to keep the hydrogen atoms from recombining.
Rockets are, as I've said before, a horribly inefficient method of travel, since conservation of momentum means that you're hurling huge masses of material out the back end, and it�s taking most of your energy supply with it. In fact, the more "efficient" your rocket in terms of payload to fuel ratio, the higher the percentage of your energy supply is going into your exhaust stream.
Also, with chemical reactions as your energy source, you can't really use hydrogen as your exhaust gas, because it isn�t the product gas of the energetic reactions you'd like to use, always assuming that you don't actually have tanks of monoatomic hydrogen lying around. MH would produce some pretty hot molecular hydrogen when it recombined, so that would work. Too bad about the world wide unobtainium shortage.
All the speed of sound issues apply to explosively driven projectiles, aka "guns," as well, though such projectiles are much more efficient than rockets, energetically speaking. Mass drivers of all sorts have the advantage of using the Earth as a big momentum sink, and when you use something that large to absorb the recoil, it doesn't get much of the energy in the bargain.
You can't generally use hydrogen and liquid oxygen in a bullet (though there are some cannon designs that do), so typical muzzle velocities are limited by the average mass of the molecules in gases like nitrogen and carbon dioxide. Those have greater masses and hence lower particle velocities than does water vapor, to say nothing of hydrogen.
But then we come to gas guns, where the projectile is driven by compressed gas. Sure, you usually can't get the pressures in a compressed gas cylinder as high as you get from an explosive, but you can then use hydrogen, or helium as the gas. Helium, being honestly monoatomic, has only twice the mass of a hydrogen molecule, so its RMS and speed of sound is still pretty fast, which is why you get a high pitched voice if you inhale helium.
If you use a compressed gas cylinder, you have what is called a "single stage gas gun," which rather demands an answer to what a "two stage gas gun" is, right? Ah, there it gets interesting. In a two stage gas gun, you use an explosively driven piston to ram the gas into the compression chamber. Then, when it reaches a nice, high pressure (and remember, it's also been heated via compression), it ruptures a perforated valve and slams into the projectile, which is then propelled out of the barrel of the gun. Some designs preheat the original gas as well; you can exceed the melt temperatures for parts of the device for brief periods of time, and gun shots are nothing if not brief.
Lawrence Livermore Laboratory has a nice two stage gas gun that can propel a projectile weighing 5 kilograms to 3 kilometers per second. There were plans in the early 1990s, to upgrade the thing and to use lower weight projectiles, which would reach 8 kilometers per second, and LLL wanted to try putting things into orbit with it. Instead, absent the $1 billion upgrade, they had to content themselves with firing the thing into a liquid hydrogen target, experimentally demonstrating the existence of the previously only theoretical metallic phase of hydrogen. And even without quite so lavish funding, they do seem to have managed to get up to the 8 km/sec range, albeit with pretty light projectiles.
Theory doesn�t quite run out of oomph at 8 km/sec, however. As you go to higher and higher temperatures in hydrogen, you begin to get molecular dissociation. Heat your original gas hot enough, and compress it enough, and you can get a gas containing significant amounts of--wait for it--monoatomic hydrogen. I've seen a design document from The Rand Corporation on how to build one of those, and its theoretical top projectile velocity exceeds 10 km/sec. That's flirting with escape velocity and it's well over orbital velocity. It may also be getting close to the velocity necessary to compress inertial fusion materials to the point where a tritium-deuterium burn can occur, but that's a different essay, for another time.
Saturday, February 9, 2008
One of the Places where it all Began
That was then:
We were somewhere around Barstow on the edge of the desert when the drugs began to take hold. I remember saying something like, "I feel a bit lightheaded; maybe you should drive . . ."And suddenly there was a terrible roar all around us and the sky was full of what looked like huge bats, all swooping and screeching and diving around the car, which was going about 100 miles an hour with the top down to Las Vegas. And a voice was screaming: "Holy Jesus! What are these goddamn animals?"
Then it was quiet again. My attorney had taken his shirt off and was pouring beer on his chest, to facilitate the tanning process. "What the hell are you yelling about," he muttered, staring up at the sun with his eyes closed and covered with wraparound Spanish sunglasses. "Never mind," I said. "It's your turn to drive." I hit the brakes and aimed the Great Red Shark toward the shoulder of the highway. No point mentioning those bats, I thought. The poor bastard will see them soon enough. --Fear and Loathing in Las Vegas, Hunter S. Thompson
This is Now:
Saturday noon. Recollection of the last 24 hours is excruciatingly difficult; I have taken every remaining pill in my kit bag, and yet somehow, despite the presence of enough chemicals in my system to transform me into the Joker, I have developed a raging cold. My throat is nearly sealed shut, which may work to my advantage since I’m reaching the point at which the rude answers which bubble up in my skull every time someone speaks to me are threatening to spill over into actual vocalization. Ever since Wednesday I have been asking myself in re my pharmacopia: how many is too many? Crashing into every sharp corner in my hotel room, I know the answer: however many I took when I woke up this morning.
Last night was the Ronald Reagan Banquet, a dinner which was for and unfortunately not of Ronald Reagan. Eating a dehydrated teriyaki jerky chunk of the old fraud might have given me some of his strength. I’ve heard the words “Ronald Reagan” and “tax cuts” so many times now they’re beginning to lose whatever meaning they might have once had, and Will, that payola-stuffed bloviator of manifest destiny, will say them another three dozen times while I tuck into my mashed potatoes. After the ghouls-gone-wild reception given to Ann Coulter a few hours ago, the crowd receives him politely and respectfully, and even considering the fact that this is an older crowd, made up largely of the parents of the rich kids hooting and snarling at Ann’s anti-McCain jeremiad, it still has the tone of someone forced to hear their grandpa read cowboy poetry just after they’ve come back from yelling “SHOW US YOUR TITS!” to drunken frat girls. Will himself is perfunctory at best, showing his chipper cheerleader side only when discussing Old Mother Reagan; the rest of the time, he’s just there to pick up a check. He even senses the hostility in the room when called upon to mention the Supplicant McCain: urging the crowd to be “happy warriors” for the default candidate, he sounds like a bored Sunday school teacher leading his tenth consecutive round of “I’ve Got the Joy” for a group of sugared-up fourth-graders.--Mister Leonard Pierce, The Beast is Red, Chapter 12: Show Us Your Twits, from Sadly, No.
Corporate Libertarians
One of the paradoxes of Robert Heinlein was that he wrote one of the two sacred texts of libertarianism (The Moon is a Harsh Mistress), believed firmly in individualism, and also held the belief that military service was an essential part of that individualism.
To be sure, Heinlein explicitly stated that a healthy society was essential to the individual, so he believed that individualists must also include the social good as part of their own. It’s a sophisticated position, and I only disagree on practically all the details, especially when it leads to things like the belief that Napoleon was some sort of triumphant individualist (a position sometimes attributed to Nietzsche, or that Cesare Borgia was a paragon of enlightened self-interest (Machiavelli).
Current libertarians are less keen on their own personal membership in the military, but they do often identify with collective behavior and groups. However, for a good many libertarians, group identification seems to be with the modern corporation, sometimes called “private enterprise.” I’ll also note that “value” is often assumed to be monetary, and nothing more. For commercial enterprises, of which the public corporation is a good example, that is pretty easy to understand. It’s not quite as clear-cut for individuals, but that mistake is obviously not limited to libertarians.
This “corporate libertarian” critique does not hold for all libertarians. There is, after all, no secret libertarian handshake, no membership card, etc. Anyone can call themselves a libertarian. Still, the most annoying ones are those who fail to understand that the limited liability corporation is a profoundly privileged beast, one whose existence weakens such things as the individual right-to-contract, and individual property rights in general. I will stipulate at the outset that I think the corporation is a very powerful and useful invention, but it does require certain sorts of regulation if it isn’t to seriously harm individual rights, and often corporate libertarians seem more interested in eliminating those essential regulations than upholding the underlying individual rights.
Let’s consider how this can work with an extreme case: contract murder. I’m sure pretty much everyone would recognize that a contract to perform an illegal act is itself an illegal contract, and totally unenforceable. Furthermore, it’s pretty easy to see that both parties in a contract hit (the killer and the one who pays for the killing) are guilty of criminal conspiracy.
What would be the effect of making such contracts legal, and absolving the one who takes out the contract from penalty? Obviously this would weaken criminal law, but less obviously, it would also weaken contract law, since it would set civil law against criminal law. In a similar way, the institution of slavery weakens the institution of property, by putting property rights into opposition to human rights. Property rights in the South during the Civil War were often pretty shaky, what with the armies marching through and all.
The limited liability corporation puts many decisions behind a financial “firewall.” Stockholders and their agents (corporate boards and management) can undertake actions that, potentially, have far greater adverse consequences than they would deem acceptable if their whole net worth was at risk, as it would be in a proprietorship. This means that when individuals enter into contracts with corporations, the exchange is even more one-sided than if it were a matter of an individual contracting against someone with greater resources.
The anti-environmentalism exhibited by many corporate libertarians is another symptom of psychological projection and identification. If, for example, individuals do not have a property right on the air they breathe, then property rights (and individual rights generally) are pretty much meaningless. Similarly, if I own real property that has a stream running through it, I possess certain rights that preclude those upstream from having absolute authority over that stream as it passes through their property. In common law, this would be an easement; Federal and State laws are usually even more explicit and restrictive—to the fury of anti-environmentalists.
Similar easement rights surely exist for such things as migratory animals, flood control, protection of ground water, ecological integrity and so forth. I have an interest in all of these that is best expressed (in my view) as a property right. However, since such things are difficult to monetize, they do not show up in corporate thinking. Generally, only individuals value such things, and since corporate “rights” trump individual rights, then the corporate libertarian inevitably leans toward anti-environmentalism. For that matter, so does anyone who cannot imagine any value except insofar as it can be measured in monetary terms.
To be sure, Heinlein explicitly stated that a healthy society was essential to the individual, so he believed that individualists must also include the social good as part of their own. It’s a sophisticated position, and I only disagree on practically all the details, especially when it leads to things like the belief that Napoleon was some sort of triumphant individualist (a position sometimes attributed to Nietzsche, or that Cesare Borgia was a paragon of enlightened self-interest (Machiavelli).
Current libertarians are less keen on their own personal membership in the military, but they do often identify with collective behavior and groups. However, for a good many libertarians, group identification seems to be with the modern corporation, sometimes called “private enterprise.” I’ll also note that “value” is often assumed to be monetary, and nothing more. For commercial enterprises, of which the public corporation is a good example, that is pretty easy to understand. It’s not quite as clear-cut for individuals, but that mistake is obviously not limited to libertarians.
This “corporate libertarian” critique does not hold for all libertarians. There is, after all, no secret libertarian handshake, no membership card, etc. Anyone can call themselves a libertarian. Still, the most annoying ones are those who fail to understand that the limited liability corporation is a profoundly privileged beast, one whose existence weakens such things as the individual right-to-contract, and individual property rights in general. I will stipulate at the outset that I think the corporation is a very powerful and useful invention, but it does require certain sorts of regulation if it isn’t to seriously harm individual rights, and often corporate libertarians seem more interested in eliminating those essential regulations than upholding the underlying individual rights.
Let’s consider how this can work with an extreme case: contract murder. I’m sure pretty much everyone would recognize that a contract to perform an illegal act is itself an illegal contract, and totally unenforceable. Furthermore, it’s pretty easy to see that both parties in a contract hit (the killer and the one who pays for the killing) are guilty of criminal conspiracy.
What would be the effect of making such contracts legal, and absolving the one who takes out the contract from penalty? Obviously this would weaken criminal law, but less obviously, it would also weaken contract law, since it would set civil law against criminal law. In a similar way, the institution of slavery weakens the institution of property, by putting property rights into opposition to human rights. Property rights in the South during the Civil War were often pretty shaky, what with the armies marching through and all.
The limited liability corporation puts many decisions behind a financial “firewall.” Stockholders and their agents (corporate boards and management) can undertake actions that, potentially, have far greater adverse consequences than they would deem acceptable if their whole net worth was at risk, as it would be in a proprietorship. This means that when individuals enter into contracts with corporations, the exchange is even more one-sided than if it were a matter of an individual contracting against someone with greater resources.
The anti-environmentalism exhibited by many corporate libertarians is another symptom of psychological projection and identification. If, for example, individuals do not have a property right on the air they breathe, then property rights (and individual rights generally) are pretty much meaningless. Similarly, if I own real property that has a stream running through it, I possess certain rights that preclude those upstream from having absolute authority over that stream as it passes through their property. In common law, this would be an easement; Federal and State laws are usually even more explicit and restrictive—to the fury of anti-environmentalists.
Similar easement rights surely exist for such things as migratory animals, flood control, protection of ground water, ecological integrity and so forth. I have an interest in all of these that is best expressed (in my view) as a property right. However, since such things are difficult to monetize, they do not show up in corporate thinking. Generally, only individuals value such things, and since corporate “rights” trump individual rights, then the corporate libertarian inevitably leans toward anti-environmentalism. For that matter, so does anyone who cannot imagine any value except insofar as it can be measured in monetary terms.
Thursday, February 7, 2008
Final Chapter, or Is It?
Just a little note to announce that the first book of Dark Underbelly is now complete. Some mysteries are now solved, some are not, and there will be a second serial coming soon.
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