Author Archives: R.E. Buxbaum

About R.E. Buxbaum

Robert Buxbaum is a life-long engineer, a product of New York's Brooklyn Technical High School, New York's Cooper Union to Science and Art, and Princeton University where he got a PhD in Chemical Engineering. From 1981 to 1991 he was a professor of Chemical Engineering at Michigan State, and now runs an engineering shop in Oak Park, outside of Detroit, Michigan. REB Research manufactures and sells hydrogen generation and purification equipment. He's married with 3 wonderful children who, he's told, would prefer to not be mentioned except by way of complete, unadulterated compliments. As of 2016, he's running to be the drain commissioner/ water resources commissioner of Oakland county.

Keeping your car batteries alive.

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Lithium-battery cost and performance has improved so much that no one uses Ni-Cad or metal hydride batteries any more. These are the choice for tools, phones, and computers, while lead acid batteries are used for car starting and emergency lights. I thought I’d write about the care and trade-offs of these two remaining options.

As things currently stand, you can buy a 12 V, lead-acid car battery with 40 Amp-h capacity for about $95. This suggests a cost of about $200/ kWh. The price rises to $400/kWh if you only discharge half way (good practice). This is cheaper than the per-power cost of lithium batteries, about $500/ kWh or $1000/ kWh if you only discharge half-way (good practice), but people pick lithium because (1) it’s lighter, and (2) it’s generally longer lasting. Lithium generally lasts about 2000 half-discharge cycles vs 500 for lead-acid.

On the basis of cost per cycle, lead acid batteries would have been replaced completely except that they are more tolerant of cold and heat, and they easily output the 400-800 Amps needed to start a car. Lithium batteries have problems at these currents, especially when it’s hot or cold. Lithium batteries deteriorate fast in the heat too (over 40°C, 105°F), and you can not charge a lithium car battery at more than 3-4 Amps at temperatures below about 0°C, 32°F. At higher currents, a coat of lithium metal forms on the anode. This lithium can react with water: 2Li + H2O –> Li2O + H2, or it can form dendrites that puncture the cell separators leading to fire and explosion. If you charge a lead acid battery too fast some hydrogen can form, but that’s much less of a problem. If you are worried about hydrogen, we sell hydrogen getters and catalysts that remove it. Here’s a description of the mechanisms.

The best thing you can do to keep a lead-acid battery alive is to keep it near-fully charged. This can be done by taking long drives, by idling the car (warming it up), or by use of an external trickle charger. I recommend a trickle charger in the winter because it’s non-polluting. A lead-acid battery that’s kept at near full charge will give you enough charge for 3000 to 5000 starts. If you let the battery completely discharge, you get only 50 or so deep cycles or 1000 starts. But beware: full discharge can creep up on you. A new car battery will hold 40 Ampere-hours of current, or 65,000 Ampere-seconds if you half discharge. Starting the car will take 5 seconds of 600 Amps, using 3000 Amp-s or about 5% of the battery’s juice. The battery will recharge as you drive, but not that fast. You’ll have to drive for at least 500 seconds (8 minutes) to recharge from the energy used in starting. But in the winter it is common that your drive will be shorter, and that a lot of your alternator power will be sent to the defrosters, lights, and seat heaters. As a result, your lead-acid battery will not totally charge, even on a 10 minute drive. With every week of short trips, the battery will drain a little, and sooner or later, you’ll find your battery is dead. Beware and recharge, ideally before 50% discharge

A little chemistry will help explain why full discharging is bad for battery life (for a different version see Wikipedia). For the first half discharge of a lead-acid battery, the reaction Is:

Pb + 2PbO2 + 2H2SO4  –> PbSO4 + Pb2O2SO4 + 2H2O.

This reaction involves 2 electrons and has a -∆G° of >394 kJ, suggesting a reversible voltage more than 2.04 V per cell with voltage decreasing as H2SO4 is used up. Any discharge forms PbSO4 on the positive plate (the lead anode) and converts lead oxide on the cathode (the negative plate) to Pb2O2SO4. Discharging to more than 50% involves this reaction converting the Pb2O2SO4 on the cathode to PbSO4.

Pb + Pb2O2SO4 + 2H2SO4  –> 2PbSO4 + 2H2O.

This also involves two electrons, but -∆G < 394 kJ, and voltage is less than 2.04 V. Not only is the voltage less, the maximum current is less. As it happens Pb2O2SO4 is amorphous, adherent, and conductive, while PbSO4 is crystalline, not that adherent, and not-so conductive. Operating at more than 50% results in less voltage, increased internal resistance, decreased H2SO4 concentrations, and lead sulfate flaking off the electrode. Even letting a battery sit at low voltage contributes to PbSO4 flaking off. If the weather is cold enough, the low concentration H2SO4 freezes and the battery case cracks. My advice: Get out your battery charger and top up your battery. Don’t worry about overcharging; your battery charger will sense when the charge is complete. A lead-acid battery operated at near full charge, between 67 and 100% will provide 1500 cycles, about as many as lithium. 

Trickle charging my wife's car. Good for battery life. At 6 Amps, expect this to take 3-6 hours.

Trickle charging my wife’s car: good for battery life. At 6 Amps, expect a full charge to take 6 hours or more. You might want to recharge the battery in your emergency lights too. 

Lithium batteries are the choice for tools and electric vehicles, but the chemistry is different. For longest life with lithium batteries, they should not be charged fully. If you change fully they deteriorate and self-discharge, especially when warm (100°F, 40°C). If you operate at 20°C between 75% and 25% charge, a lithium-ion battery will last 2000 cycles; at 100% to 0%, expect only 200 cycles or so.

Tesla cars use lithium batteries of a special type, lithium cobalt. Such batteries have been known to explode, but and Tesla adds sophisticated electronics and cooling systems to prevent this. The Chevy Volt and Bolt use lithium batteries too, but they are less energy-dense. In either case, assuming $1000/kWh and a 2000 cycle life, the battery cost of an EV is about 50¢/kWh-cycle. Add to this the cost of electricity, 15¢/kWh including the over-potential needed to charge, and I find a total cost of operation of 65¢/kWh. EVs get about 3 miles per kWh, suggesting an energy cost of about 22¢/mile. By comparison, a 23 mpg car that uses gasoline at $2.80 / gal, the energy cost is 12¢/mile, about half that of the EVs. For now, I stick to gasoline for normal driving, and for long trips, suggest buses, trains, and flying.

Robert Buxbaum, January 4, 2018.

Why is it hot at the equator, cold at the poles?

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Here’s a somewhat mathematical look at why it is hotter at the equator that at the poles. This is high school or basic college level science, using trigonometry (pre calculus), a slight step beyond the basic statement that the sun hits down more directly at the equator than at the poles. That’s the kid’s explanation, but we can understand better if we add a little math.

Solar radiation hits Detroit at an angle, as a result less radiation power hits per square meter of Detroit.

Solar radiation hits Detroit or any other non-equator point at an angle, As a result, less radiation power hits per square meter of land.

Lets use the diagram at right and trigonometry to compare the amount of sun-energy that falls on a square meter of land at the equator (0 latitude) and in a city at 42.5 N latitude (Detroit, Boston, and Rome are at this latitude). In each case, let’s consider high-noon on March 21 or September 20. These are the two equinox days, the only days each year when the day and night are equal length, and the only times when it is easy to calculate the angle of the sun as it deviates from the vertical by exactly the latitude on the days and times.

More specifically the equator is zero latitude, so on the equator at high-noon on the equinox, the sun will shine from directly overhead, or 0° from the vertical. Since the sun’s power in space is 1050 W/m2, every square meter of equator can expect to receive 1050 W of sun-energy, less the amount reflected off clouds and dust, or scattered off or air molecules (air scattering is what makes the sky blue). Further north, Detroit, Boston, and Rome sit at 42.5 latitude. At noon on March 31 the sun will strike earth at 42.5° from the vertical as shown in the lower figure above. From trigonometry, you can see that each square meter of these cities will receive cos 42.5 as much power as a square meter at the equator, except for any difference in clouds, dust, etc. Without clouds etc. that would be 1050 cos 42.5 = 774 W. Less sun power hits per square meter because each square meter is tilted. Earlier and later in the day, each spot will get less sunlight than at noon, but the proportion is the same, at least on one of the equinox days.

To calculate the likely temperature in Detroit, Boston, or Rome, I will use a simple energy balance. Ignoring heat storage in the earth for now, we will say that the heat in equals the heat out. We now ignore heat transfer by way of winds and rain, and approximate to say that the heat out leaves by black-body radiation alone, radiating into the extreme cold of space. This is not a very bad approximation since Black body radiation is the main temperature removal mechanism in most situations where large distances are involved. I’ve discussed black body radiation previously; the amount of energy radiated is proportional to luminosity, and to T4, where T is the temperature as measured in an absolute temperature scale, Kelvin or Rankin. Based on this, and assuming that the luminosity of the earth is the same in Detroit as at the equator,

T Detroit / Tequator  = √√ cos 42.5 = .927

I’ll now calculate the actual temperatures. For American convenience, I’ll choose to calculation in the Rankin Temperature scale, the absolute Fahrenheit scale. In this scale, 100°F = 560°R, 0°F = 460°R, and the temperature of space is 0°R as a good approximation. If the average temperature of the equator = 100°F = 38°C = 560°R, we calculate that the average temperature of Detroit, Boston, or Rome will be about .927 x 560 = 519°R = 59°F (15°C). This is not a bad prediction, given the assumptions. We can expect the temperature will be somewhat lower at night as there is no light, but the temperature will not fall to zero as there is retained heat from the day. The same reason, retained heat, explains why it is warmer will be warmer in these cities on September 20 than on March 31.

In the summer, these cities will be warmer because they are in the northern hemisphere, and the north pole is tilted 23°. At the height of summer (June 21) at high noon, the sun will shine on Detroit at an angle of 42.5 – 23° = 19.5° from the vertical. The difference in angle is why these cities are warmer on that day than on March 21. The equator will be cooler on that day (June 21) than on March 21 since the sun’s rays will strike the equator at 23° from the vertical on that day. These  temperature differences are behind the formation of tornadoes and hurricanes, with a tornado season in the US centering on May to July.

When looking at the poles, we find a curious problem in guessing what the average temperature will be. At noon on the equinox, the sun comes in horizontally, or at 90°from the vertical. We thus expect there is no warming power at all this day, and none for the six months of winter either. At first glance, you’d think the temperature at the poles would be zero, at least for six months of the year. It isn’t zero because there is retained heat from the summer, but still it makes for a more-difficult calculation.

To figure an average temperature of the poles, lets remember that during the 6 month summer the sun shines for 24 hours per day, and that the angle of the sun will be as high as 23° from the horizon, or 67° from the vertical for all 24 hours. Let’s assume that the retained heat from the summer is what keeps the temperature from falling too low in the winter and calculate the temperature at an .

Let’s assume that the sun comes in at the equivalent of 25° for the sun during the 6 month “day” of the polar summer. I don’t look at equinox, but rather the solar day, and note that the heating angle stays fixed through each 24 hour day during the summer, and does not decrease in the morning or as the afternoon wears on. Based on this angle, we expect that

TPole / Tequator  = √√ cos 65° = .806

TPole = .806 x 560°R = 452°R = -8°F (-22°C).

This, as it happens is 4° colder than the average temperature at the north pole, but not bad, given the assumptions. Maybe winds and water currents account for the difference. Of course there is a large temperature difference at the pole between the fall equinox and the spring equinox, but that’s to be expected. The average is, -4°F, about the temperature at night in Detroit in the winter.

One last thing, one that might be unexpected, is that temperature at the south pole is lower than at the north pole, on average -44°F. The main reason for this is that the snow on south pole is quite deep — more than 1 1/2 miles deep, with some rock underneath. As I showed elsewhere, we expect that, temperatures are lower at high altitude. Data collected from cores through the 1 1/2 mile deep snow suggest (to me) chaotic temperature change, with long ice ages, and brief (6000 year) periods of warm. The ice ages seem far worse than global warming.

Dr. Robert Buxbaum, December 30, 2017

Gomez Addams, positive male role-model

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The Addams Family did well on Broadway, in the movies, and on TV, but got predictably bad reviews in all three forms. Ordinary people like it; critics did not. Something I like about the series that critics didn’t appreciate is that Gomez is the only positive father character I can think of since the days of “Father knows best”.

Gomez is sexual, and sensual; a pursuer and lover, but not a predator.

Gomez is sexual, and sensual; a pursuer and lover, but not a predator.

In most family shows the father isn’t present at all, or if he appears, he’s violent or and idiot. He’s in prison, or in trouble with the law, regularly insulted by his wife and neighbors, in comedies, he’s sexually ambiguous, insulted by his children, and often insulted by talking pets too. In Star Wars, the only father figures are Vader, a distant menace, and Luke who’s just distant. In American shows, the parents are often shown as divorced; the children are reared by the mother with help of a nanny, a grandparent, or a butler. In Japanese works, I hardly see a parent. By contrast, Gomez is present, center stage. He’s not only involved, he’s the respected leader of his clan. If he’s odd, it’s the odd of a devoted father and husband who comfortable with himself and does not care to impress others. It’s the outsiders, the visitors, who we find have family problems, generally caused by a desire to look perfect.

Gomez is hot-blooded, sexual and sensual, but he’s not a predator, or violent. He’s loved by his wife, happy with his children, happy with his life, and happy with himself. As best we can tell, he’s on good-enough terms with the milk man, the newspaper boy, and the law. Though not a stick-in-the-mud, he’s on excellent terms with the rest of the Addams clan, and he’s good with the servants: Lurch, Thing, and for a while a gorilla who served as maid (none too well). One could do worse than to admire a person who maintains a balance like that between the personal, the family, the servants, and the community.

On a personal level, Gomez is honest, kind, generous, loving, and involved. He has hobbies, and his hobbies are manly: fencing, chess, dancing, stocks, music, and yoga. He reads the newspaper and smokes a cigar, but is not addicted to either. He plays with model trains too, an activity he shares with his son. Father and son enjoy blowing up the train — it’s something kids used to do in the era of firecrackers. Gomez is not ashamed to do it, and approves when his son does.

Gomez Addams, in the Addams Family Musical, gives advice and comfort to his daughter who is going through a rough stretch of relationship with a young man, and sings that he’s happy and sad.

Other TV and movie dads have less – attractive hobbies: football watching and beer-drinking, primarily. Han Solo is a smuggler, though he does not seem to need the money. TV dads take little interest in their kids, and their kids return the favor. To the extent that TV dads take an interest, it’s to disapprove, George Costanza’s dad, for example. Gomez is actively interested and is asked for advice regularly. In the video below, he provides touching comfort and advice to his daughter while acknowledging her pain, and telling her how proud he is of her. Kids need to hear that from a dad. No other TV dad gives approval like this; virtually no other male does. They are there as props, I think, for strong females and strong children.

The things that critics dislike, or don’t understand, as best I can tell, is the humor, based as it is on danger and dance. Critics hate humor in general (How many “best picture” Oscars go to comedies?)  Critics fear pointless danger, and disapproval, and law suits, and second-hand-smoke. They are the guardians of correct thinking — just the thinking that Gomez and the show ridicules. Gomez lives happily in the real world of today, but courts danger, death, law suits. He smokes and dances and does not worry what the neighbors think. He tries dangerous things and does not always succeed, but then lets his kids try the same. He dances with enthusiasm. I find his dancing and fearlessness healthier than the over-protective self-sacrifice that critics seem to favor in heroes. To the extent that they tolerate fictional violence, they require the hero to swooping, protecting others at danger to themselves only, while the others look on (or don’t). The normal people are presented as cautious, fearful, and passive. Cold, in a word, and we raise kids to be the same. Cold fear is a paralyzing thing in children and adults; it often brings about the very damage that one tries to avoid.

Gomez is hot: active, happy, and fearless. This heat.– this passion — is what makes Gomez a better male role model than Batman, say. Batman is just miserable, or the current versions are. Ms. Frizzle (magic school bus) is the only other TV character who is happy to let others take risks, but Ms Frizzle is female. Gomez’s thinks the best of those who come to visit, but we see they usually don’t deserve it. Sometimes they do, and this provides touching moments. Gomez is true to his wife and passionate, most others are not. Gomez kisses his wife, dances with her, and compliments her. Outsiders don’t dance, and snap at their wives; they are motivated by money, status, and acceptability. Gomez is motivated by life itself (and death). The outsiders fear anything dangerous or strange; they are cold inside and suffer as a result. Gomez is hot-blooded and alive: as a lover, a dancer, a fencer, a stock trader, an animal trainer, and a collector. He is the only father with a mustache, a sign of particular masculinity — virtually the only man with a mustache.

Gomez has a quiet, polite and decent side too, but it’s a gallant version, a masculine heterosexual version. He’s virtually the only decent man who enjoys life, or for that matter is shown to kiss his wife with more than a peck. In TV or movies, when you see a decent, sensitive, or polite man, he is asexual or homosexual. He is generally unmarried, sometimes divorced, and almost always sad — searching for himself. I’m not sure such people are positive role models for the a-sexual, but they don’t present a lifestyle most would want to follow. Gomez is decent, happy, and motivated; he loves his life and loves his wife, even to death, and kisses with abandon. My advice: be alive like Gomez, don’t be like the dead, cold, visitors and critics.

Robert Buxbaum, December 22, 2017.  Some years ago, I gave advice to my daughter as she turned 16. I’ve also written about Superman, Hamilton, and Burr; about Military heroes and Jack Kelly.

Hydrogen permeation rates in Inconel, Hastelloy and stainless steels.

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Some 20 years ago, I published a graph of the permeation rate for hydrogen in several metals at low pressure, See the graph here, but I didn’t include stainless steel in the graph.

Hydrogen permeation in clean SS-304; four research groups’ data.

One reason I did not include stainless steel was there were many stainless steels and the hydrogen permeation rates were different, especially so between austenitic (FCC) steels and ferritic steels (BCC). Another issue was oxidation. All stainless steels are oxidized, and it affect H2 permeation a lot. You can decrease the hydrogen permeation rate significantly by oxidation, or by surface nitriding, etc (my company will even provide this service). Yet another issue is cold work. When  an austenitic stainless steel is worked — rolled or drawn — some Austinite (FCC) material transforms to Martisite (a sort of stretched BCC). Even a small amount of martisite causes an order of magnitude difference in the permeation rate, as shown below. For better or worse, after 20 years, I’m now ready to address H2 in stainless steel, or as ready as I’m likely to be.

Hydrogen permeation data for SS 340 and SS 321.

Hydrogen permeation in SS 340 and SS 321. Cold work affects H2 permeation more than the difference between 304 and 321; Sun Xiukui, Xu Jian, and Li Yiyi, 1989

The first graph I’d like to present, above, is a combination of four research groups’ data for hydrogen transport in clean SS 304, the most common stainless steel in use today. SS 304 is a ductile, austenitic (FCC), work hardening, steel of classic 18-8 composition (18% Cr, 8% Ni). It shares the same basic composition with SS 316, SS 321 and 304L only differing in minor components. The data from four research groups shows a lot of scatter: a factor of 5 variation at high temperature, 1000 K (727 °C), and almost two orders of magnitude variation (factor of 50) at room temperature, 13°C. Pressure is not a factor in creating the scatter, as all of these studies were done with 1 atm, 100 kPa hydrogen transporting to vacuum.

The two likely reasons for the variation are differences in the oxide coat, and differences in the amount of cold work. It is possible these are the same explanation, as a martensitic phase might increase H2 permeation by introducing flaws into the oxide coat. As the graph at left shows, working these alloys causes more differences in H2 permeation than any difference between alloys, or at least between SS 304 and SS 321. A good equation for the permeation behavior of SS 304 is:

P (mol/m.s.Pa1/2) = 1.1 x10-6 exp (-8200/T).      (H2 in SS-304)

Because of the song influence of cold work and oxidation, I’m of the opinion that I get a slightly different, and better equation if I add in permeation data from three other 18-8 stainless steels:

P (mol/m.s.Pa1/2) = 4.75 x10-7 exp (-7880/T).     (H2 in annealed SS-304, SS-316, SS-321)

Screen Shot 2017-12-16 at 10.37.37 PM

Hydrogen permeation through several common stainless steels, as well as Inocnel and Hastelloy

Though this result is about half of the previous at high temperature, I would trust it better, at least for annealed SS-304, and also for any annealed austenitic stainless steel. Just as an experiment, I decided to add a few nickel and cobalt alloys to the mix, and chose to add data for inconel 600, 625, and 718; for kovar; for Hastelloy, and for Fe-5%Si-5%Ge, and SS4130. At left, I pilot all of these on one graph along with data for the common stainless steels. To my eyes the scatter in the H2 permeation rates is indistinguishable from that SS 304 above or in the mixed 18-8 steels (data not shown). Including these materials to the plot decreases the standard deviation a bit to a factor of 2 at 1000°K and a factor of 4 at 13°C. Making a least-square analysis of the data, I find the following equation for permeation in all common FCC stainless steels, plus Inconels, Hastelloys and Kovar:

P (mol/m.s.Pa1/2) = 4.3 x10-7 exp (-7850/T).

This equation is near-identical to the equation above for mixed, 18-8 stainless steel. I would trust it for annealed or low carbon metal (SS-304L) to a factor of 2 accuracy at high temperatures, or a factor of 4 at low temperatures. Low carbon reduces the tendency to form Martinsite. You can not use any of these equations for hydrogen in ferritic (BCC) alloys as the rates are different, but this is as good as you’re likely to get for basic austenitc stainless and related materials. If you are interested in the effect of cold work, here is a good reference. If you are bothered by the square-root of pressure driving force, it’s a result of entropy: hydrogen travels in stainless steel as dislocated H atoms and the dissociation H2 –> 2 H leads to the square root.

Robert Buxbaum, December 17, 2017. My business, REB Research, makes hydrogen generators and purifiers; we sell getters; we consult on hydrogen-related issues, and will (if you like) provide oxide (and similar) permeation barriers.

Change home air filters 3 times per year

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Energy efficient furnaces use a surprisingly large amount of electricity to blow the air around your house. Part of the problem is the pressure drop of the ducts, but quite a lot of energy is lost bowing air through the dust filter. An energy-saving idea: replace the filter on your furnace twice a year or more. Another idea, you don’t have to use the fanciest of filters. Dirty filters provide a lot of back-pressure especially when they are dirty.

I built a water manometer, see diagram below to measure the pressure drop through my furnace filters. The pressure drop is measured from the difference in the height of the water column shown. Each inch of water is 0.04 psi or 275 Pa. Using this pressure difference and the flow rating of the furnace, I calculated the amount of power lost by the following formula:

W = Q ∆P/ µ.

Here W is the amount of power use, Watts, Q is flow rate m3/s, ∆P = the pressure drop in Pa, and µ is the efficiency of the motor and blower, typically about 50%.

With clean filters (two different brands), I measured 1/8″ and 1/4″ of water column, or a pressure drop of 0.005 and 0.01 psi, depending on the filter. The “better the filter”, that is the higher the MERV rating, the higher the pressure drop. I also measured the pressure drop through a 6 month old filter and found it to be 1/2″ of water, or 0.02 psi or 140 Pa. Multiplying this by the amount of air moved, 1000 cfm =  25 m3 per minute or 0.42 m3/s, and dividing by the efficiency, I calculate a power use of 118 W. That is 0.118 kWh/hr. or 2.8 kWh/day.

water manometer used to measure pressure drop through the filter of my furnace. I stuck two copper tubes into the furnace, and attached a plastic hose. Pressure was measured from the difference in the water level in the hose.

The water manometer I used to measure the pressure drop through the filter of my furnace. I stuck two copper tubes into the furnace, and attached a plastic tube half filled with water between the copper tubes. Pressure was measured from the difference in the water level in the plastic tube. Each 1″ of water is 280 Pa or 0.04psi.

At the above rate of power use and a cost of electricity of 11¢/kWhr, I find it would cost me an extra 4 KWhr or about 31¢/day to pump air through my dirty-ish filter; that’s $113/year. The cost through a clean filter would be about half this, suggesting that for every year of filter use I spend an average of $57t where t is the use life of the filter.

To calculate the ideal time to change filters I set up the following formula for the total cost per year $, including cost per year spent on filters (at $5/ filter), and the pressure-induced electric cost:

$ = 5/t + 57 t.

The shorter the life of the filter, t, the more I spend on filters, but the less on electricity. I now use calculus to find the filter life that produces the minimum $, and determine that $ is a minimum at a filter life t = √5/57 = .30 years.  The upshot, then, if you filters are like mine, you should change your three times a year, or so; every 3.6 months to be super-exact. For what it’s worth, I buy MERV 5 filters at Ace or Home Depot. If I bought more expensive filters, the optimal change time would likely be once or twice per year. I figure that, unless you are very allergic or make electronics in your basement you don’t need a filter with MERV rating higher than 8 or so.

I’ve mentioned in a previous essay/post that dust starts out mostly as dead skin cells. Over time dust mites eat the skin, some pretty nasty stuff. Most folks are allergic to the mites, but I’m not convinced that the filter on your furnace dies much to isolate you from them since the mites, etc tend to hang out in your bed and clothes (a charming thought, I know).

Old fashioned, octopus furnace. Free convection.

Old fashioned, octopus furnace. Free convection.

The previous house I had, had no filter on the furnace (and no blower). I noticed no difference in my tendency to cough or itch. That furnace relied for circulation on the tendency for hot air to rise. That is, “free convection” circulated air through the home and furnace by way of “Octopus” ducts. If you wonder what a furnace like that looks like here’s a picture.

I calculate that a 10 foot column of air that is 30°C warmer than that in a house will have a buoyancy of about 0.00055 psi (1/8″ of water). That’s enough pressure to drive circulation through my home, and might have even driven air through a clean, low MERV dust filter. The furnace didn’t use any more gas than a modern furnace would, as best I could tell, since I was able to adjust the damper easily (I could see the flame). It used no electricity except for the thermostat control, and the overall cost was lower than for my current, high-efficiency furnace with its electrical blower and forced convection.

Robert E. Buxbaum, December 7, 2017. I ran for water commissioner, and post occasional energy-saving or water saving ideas. Another good energy saver is curtains. And here are some ideas on water-saving, and on toilet paper.

Bitcoin risks, uses, and bubble

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Bitcoin prices over the last 3 years

Bitcoin prices over the last 3 years

As I write this, the price of a single bitcoin is approximately $11,100 yesterday, up some 2000% in the last 6 months. The rise rate suggests it is a financial bubble. Or maybe it’s not: just a very risky investment suited for inclusion in a regularly balanced portfolio. These are two competing views of bitcoin, and there are two ways to distinguish between them. One is on the basis of technical analysis — does this fast rise look like a bubble (Yes!), and the other is to accept that bitcoin has a fundamental value, one I’ll calculate that below. In either case, the price rise is so fast that it is very difficult to conclude that the rise is not majorly driven by speculation: the belief that someone else will pay more later. The history of many bubbles suggests that all bubbles burst sooner or later, and that everyone holding the item loses when it does. The only winners are the brokers and the last investors who get out just before the burst. The speculator thinks that’s going to be him, while the investor uses rebalancing to get some of benefit and fun, without having to know exactly when to get out.

That bitcoin is a bubble may be seen by comparing the price three years ago. At that point it was $380 and dropping. A year later, it was $360 and rising. One can compare the price rise of the past 2-3 years with that for some famous bubbles and see that bitcoin has risen 30 times approximately, an increase that is on a path to beat them all except, perhaps, the tulip bubble of 1622.

A comparison between Bitcoin prices, and those of tulips, 1929 stocks, and other speculative bubbles; multiple of original price vs year from peak.

A comparison between Bitcoin prices, and those of tulips, 1929 stocks, and other speculative bubbles; multiple of original price vs year from peak.

That its price looks like a bubble is not to deny that bitcoin has a fundamental value. Bitcoin is nearly un-counterfeit-able, and its ownership is nearly untraceable. These are interesting properties that make bitcoin valuable mostly for illegal activity. To calculate the fundamental value of a bitcoin, it is only necessary to know the total value of bitcoin business transactions and the “speed of money.” As a first guess, lets say that all the transactions are illegal and add up to the equivalent of the GDP of Michigan, $400 billion/year. The value of a single bitcoin would be this number divided by the number of bitcoin in circulation, 15,000,000 currently, and by the “speed of money,” the number of business transactions per year per coin. I’ll take this to be 3 per year. It turns out there are 5 bitcoin transactions total per year per coin, but 2/5 of that, I’ll assume, are investment transactions. Based on this, a single bitcoin should be worth about $8890, slightly below its current valuation. The gross speed number, 5/year, includes bitcoin transactions that are investments and never traded for goods, and those actively being used in smuggling, drug-deals, etc.

If the bitcoin trade will grow to $600 billion year in a year with no other change, the price rise of a single coin would surpass that of Dutch tulip bulbs except that more coins are bing minted, and that the speed is increasing. If you assume that coin use will reach $1,600 billion/year, the GDP of Texas in the semi-near future, before the Feds jump in, the fundamental value of a coin should grow no higher than $44,000 or so. There are several problems for bitcoin investors who are betting on this. One is that the Feds are unlikely to tolerate so large an unregulated, illegal economy. Another is that bitcoin transactions are not likely to go totally legal. It is very hard (near impossible) to connect a bitcoin to its owner. This is a plus for someone trying to deal in drugs or trying hide profits from the IRS (or his spouse), but a legal merchant will want the protection of courts of law. For this, he or she needs to demonstrate ownership of the item being traded, and that is not available with bitcoin. The lack of a solid, legitimate business need suggests to me that the FBI will likely sweep in sooner or later, and that the value of a coin will never reach $44,000.

Yet another problem for those wishing to invest in bitcoin is the existence of more bitcoins (undiscovered, or un-mined so far) and the existence of other cryptocurrencies with the same general qualities: Litecoin (LTC), Ethereum (ETH), and Zcash (ZEC) as examples. The existence of these coins increases the divisor one should use when calculating the value of a bitcoin. The total number of bitcoins is capped at 21,000,000, that is 6,000,000 coins more than known today. Assuming more use and more acceptance, the speed (turnovers per year) is likely to increase to four or five, similar to that of other currencies. Let’s assume that the bitcoin will control 1 trillion dollars per year of a $1.6 trillion/year illegal market. One can now calculate the maximum long term target price of a bitcoin by dividing $1 trillion/year by the number of bitcoins, 21,000,000, and by the speed of commercial use, 4.5/year. This suggests a maximum fundamental value of $10,582 per coin. This is just about the current price. Let the investment buyer beware.

For an amusing, though not helpful read into the price: here are Bill Gates, Warren Buffet, Charlie Munger, and Noam Chomsky discussing Bitcoin.

Robert Buxbaum, December 3, 2017.

How to tell a genius from a nut.

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In my time in college, as a student, grad student, and professor, I ran into quite a few geniuses and quite a few weirdos. Most of the geniuses were weird, but most of the weirdos were not geniuses. Many geniuses drank or smoked pot, most drunks and stoners were stupid, paranoids. My problem was finding a reasonably quick way to tell the geniuses from the nuts; tell Einsteins from I’m-stoned.kennedy thought

Only quick way I found is by their friends. If someone’s friends are dullards, chances are they are too. Related to this is humility. Most real geniuses have a body of humility that can extent to extreme self-doubt. They are aware of what they don’t know, and are generally used to skepticism and having to defend their ideas. A genius will do so enthusiastically, happy to have someone listen; a non genius will bristle at tough questions, responding by bluster, bragging, name dropping, and insult. A science genius will do math, and will show you interesting math stuff just for fun, a nut will not. Nuts will use big words will have few friends you’d want to hang with. A real genius uses simple words.

Another tell, those with real knowledge are knowledgeable on what others think (there’s actually a study on this). That is, they are able to speak in the mind-set of others, pointing out the logic of the other side, and practical differences where the other side would be right. There should be a clear reason to come on one side or the other, and not just a scream of frustration that you don’t agree. The ability to see the world through others’ eyes is not a proof they are right — some visionary geniuses have been boors, but it is a tell. Besides boors are no fun to be with; they are worth avoiding if possible.

education test treeAnd what of folks who are good to talk to; decent, loyal, humble, and fun, but turn out to be not-geniuses. I’d suggest looking a little closer. At the worst, these are good friends, boon companions, and decent citizens — far more enjoyable to deal with than the boors. But if you look closer, you may find a genius in a different area — a plumbing genius, or a police genius, or a short-order cook genius. One of my some-time employees is a bouncer-genius. He works as a bouncer and has the remarkable ability to quite people down, or throw them out, without causing a fight — it’s not an easy skill. In my political work trying to become drain commissioner, I ran into a sewage genius, perhaps two. These are hard-working people that I learn from.

People make the mistake of equating genius with academia, but that’s just a very narrow slice of genius. They then compound the mistake by looking at grades. It pays to look at results and to pay respects accordingly. To quote an old joke/ story: what do you call the fellow who graduated at the bottom of his medical school class? “Doctor” He or she is a doctor. And what do you call the fellow who graduated at the bottom of his law school class? “your honor.”

Robert Buxbaum, November 27, 2017.

Why Warren Buffett pays 0% social security tax

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Social Security is billed along with Medicare (health care for the poor) as an anti-flat tax called FICA where middle class workers pay 7.65 -15.3%, and rich people pay essentially 0%. The reason that Warren Buffet and other rich people pay 0%, on a percentage basis, far less than their secretaries, is that there is a FICA cap of $127,200 currently, and he earns far more than $127,200. Buffett’s secretaries pays 7.65%, or which 6% approximately is social-security payment, and the rest Medicare. Buffett’s company then matches the 7.65% — a situation that applies to virtually every employee in the US.

A self employed person though, a gardener say, pays both the employee and employer portion or 15.3%. The same $127,200 cap applies, but since few gardeners make more than this amount, they are likely to pay 15.3% on all earnings, with no deductions. FICA really socks the poor and middle class, and barely touches a rich man like Buffett. This is the tax-inequality that most needs addressing, in my opinion, and one I have not heard discussed.

A short history of FICA

A visual history of FICA rates (right), and of the salary cap (left). Medicare contributions were added in 1966.

As I write this, there is a debate about tax reform that mostly involves income tax, but not at all FICA. Income tax could be improved, in my opinion, and should be. We could remove some exemptions that are being abused, and we should lower the general rates, especially for foreign-earnings, but the current income tax isn’t that bad, in my opinion. Buffett likes to brag about the high rate he pays, but it’s not a bad rate compared to the rest of the world. And Buffett benefits from a lot of things we don’t. His income is taxed at a lower rate than a worker’s would be since most of it is unearned. And, like most rich folks, he has exemptions and deductions that do not apply to most. He can deduct cars, private airplanes, and interest; most folks don’t deduct these things since they don’t spend enough to exceed the “standard deduction”. I’m happy to say these issues are being addressed in the current tax re-write.

The current, House version of the GOP tax proposal includes a raise in the standard deduction and a cap on interest and other deductions. There is a general decrease in the tax rate for earnings, and a decrease for earnings made abroad and repatriated. I’d like to see tariffs, too but they do not appear in the versions I’ve seen. And I’ve very much like to see a decrease in the FICA rate coupled with a removal of the salary cap. Pick a rate, 4% say, where we collect the same amount, but spread the burden uniformly. Why should 7.65%-15.3% or the workmanship wages got to the window, the orphan, and healthcare of the poor, while 0% of Buffett’s go for this?

Some other tax ideas: I’d like to see shorter criminal sentences, especially for drugs, and I’d like to see healthcare addressed to reduce the administrative burden.

Robert E. Buxbaum, November 17, 2017. In the news today, the senate version puts back the tax exemption on private jets. The opposite of progress, they say, is congress.

Penicillin, cheese allergy, and stomach cancer

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penecillin molecule

The penicillin molecule is a product of the penicillin mold

Many people believe they are allergic to penicillin — it’s the most common perceived drug allergy — but several studies have shown that most folks who think they are allergic are not. Perhaps they once were, but when people who thought they were allergic were tested, virtually none showed allergic reaction. In a test of 146, presumably allergic patients at McMaster University, only two had their penicillin allergy confirmed; 98.6% of the patients tested negative. A similar study at the Mayo Clinic tested 384 pre-surgical patients with a history of penicillin allergy; 94% tested negative. They were given clearance to receive penicillin antibiotics before, during, and after surgery. Read a summary here.

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Orange showing three different strains of the penicillin mold; some of these are toxic.

This is very good news. Penicillin is a low-cost, low side-effect antibiotic, effective against many diseases including salmonella, botulism, gonorrhea, and scarlet fever. The penicillin molecule is a common product of nature, produced by a variety of molds, e.g. on the orange at right, and in cheese. It is thus something people have been exposed to, whether they realize it or not.

Penicillin allergy is a deadly danger for the few who really are allergic, and it’s worthwhile to find out if that means you. The good news: that penicillin is found in common cheeses suggests, to me, a simple test for penicillin allergy. Anyone who suspects penicillin allergy and does not have a general dairy allergy can try eating appropriate cheese: brie, blue, camembert, or Stilton. That is any of the cheeses made with penicillin molds. If you don’t break out in a rash or suffer stomach cramps, you’re very likely not allergic to penicillin.

There is some difference between cheeses, so if you have problems with Roquefort, but not brie or camembert, there’s still a good chance you’re not allergic to penicillin. Brie and camembert have a white fuzzy mold coat of Penicillium camemberti. This mold exudes penicillin — not in enough quantity to cure gonorrhea, but enough to give taste and avoid spoilage, and enough to test for allergy. Danish blue and Roquefort, shown below, have a different look and a sharper flavor . They’re made with blue-green, Penicillium roqueforti. This mold produces penicillin, but also a small amount of neurotoxin, roquefortine C. It’s not enough to harm most people, but it could cause an allergic reaction to folks who are not allergic to penicillin. Don’t eat a moldy orange, by the way; some forms of the mold produce a lot of neurotoxin.

For people who are not allergic, a thought I had is that one could, perhaps treat heartburn or ulcers with cheese; perhaps even cancer? H-Pylori, the bacteria associated with heartburn, is effectively treated by amoxicillin, a penicillin variant. If a penicillin variant kills the bacteria, it seems plausible that penicillin cheese might too. And since amoxicillin, is found to reduce the risk of gastric cancer, it’s reasonable to expect that penicillin or penicillin cheese might be cancer-protective. To my knowledge, this has never been studied, but it seems worth considering. The other, standard treatment for heartburn, pantoprazole / Protonix, is known to cause osteoporosis, and increase the risk of cancer, and it doesn’t taste as good as cheese.

A culture of Penicillium roqueforti. Most people are not allergic to it.

The blue in blue cheese is Penicillium roqueforti. Most people are not allergic.

Penicillin was discovered by Alexander Fleming, who noticed that a single spore of the mold killed the bacteria near it on a Petrie dish. He tried to produce significant quantities of the drug from the mold with limited success, but was able to halt disease in patients, and was able to interest others who had more skill in large-scale fungus growing. Kids looking for a good science fair project, might consider penicillin growing, penicillin allergy, treatment of stomach ailments using cheese, or anything else related to the drug. Three Swedish journals declared that penicillin was the most important discovery of the last 1000 years. It would be cool if the dilute form, the one available in your supermarket, could be shown to treat heartburn and/or cancer. Another drug you could study is Lysozyme, a chemical found in tears, in saliva, and in human milk (but not in cow milk). Alexander Fleming found that tears killed bacteria, as did penicillin. Lysozyme, the active ingredient, is currently used to treat animals, but not humans.

Robert Buxbaum, November 9, 2017. Since starting work on this essay I’ve been eating blue cheese. It tastes good and seems to cure heartburn. As a personal note: my first science fair project (4th grade) involved growing molds on moistened bread. For an incubator, I used the underside of our home radiator. The location kept my mom from finding the experiment and throwing it out.

Forced diversity of race is racist

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Let me browse through some thoughts on efforts to address endemic racism. I’m not sure I’ll get anywhere, but you might as well enter the laboratory of my mind on the issue.

I’d like to begin with a line of the bible (why not?) “‘Do not pervert justice; do not show partiality to the poor or favoritism to the great, but judge your neighbor fairly.” (Lev. 19:15). This sounds good, but in college admissions, I’ve found we try to do better by showing  favoritism to the descendants of those who’ve been historically left-out. This was called affirmative action, it’s now called “diversity”.  

In 1981, when I began teaching chemical engineering at Michigan State University, our department had race-based quotas to allow easier admission to the descendants of historically-disadvantaged groups. All major universities did this at the time. The claim was that it would be temporary; it continues to this day. In our case, the target was to get 15% or so black, Hispanics and American Indians students (7 in a class of 50). We achieved this target by accepting such students with a 2.0 GPA, and not requiring a math or science background; Caucasians required 3.0 minimum, and we did require math or science. I’m not sure we helped the disadvantaged by this, either personally or professionally, but we made the administration happy. The kids seemed happy too, at least for a while. The ones we got were, by and large, bright. To make up for the lack of background we offered tutoring and adjusted grades. Some diversity students did well, others didn’t. Mostly they went into HR or management after graduation, places they could have gone without our efforts.

After some years, the Supreme court ended our quota based selection, saying it was, itself racist. They said we could still reverse-discriminate for “diversity,” though. That is, if the purpose wasn’t to address previous wrongs, but to improve the class. We changed our literature, but kept our selection methods and kept the same percentage targets as before.

This is a popular meme about racism. It makes sense to me.

This is a popular meme about racism.

The only way we monitored that we met the race-percent target was by a check-box on forms. Students reported race, and we collected this, but we didn’t check that black students look black or Hispanic students spoke Spanish. There was no check on student honesty. Anyone who checked the box got the benefits. This lack of check bread cheating at MSU and elsewhere. Senator Elizabeth Warren got easy entry into Harvard and Penn, in part by claiming to be an Indian on her forms. She has no evidence of Indian blood or culture Here’s Snopes. My sense is that our methods mostly help the crooked.

The main problem with is, I suspect, is the goal. We’ve decided to make every university department match the state’s racial breakdown. It’s a pretty goal, but it doesn’t seem like one that helps students or the state. Would it help the MSU hockey squad to force to team to racially match the state; would it help the volleyball team, or the football team?  So why assume it helps every academic department to make it’s racial makeup match the state’s. Why not let talented black students head to business or management departments before graduation. They might go further without our intervention.

This is not to say there are not racial inequalities, but I suspect that these diversity programs don’t help the students, and may actually hurt. They promote crookedness, and divert student attention from achieving excellence to maintaining victim status. Any group that isn’t loud enough in claiming victim status is robbed of the reverse-discrimination that they’ve been told they need. They’re told they can’t really compete, and many come to believe it. In several universities, we gone so far as to hire “bias referees” to protect minorities from having to defend their intellectual views in open discussion. The referee robs people of the need to think, and serves, I suspect, no one but a group of powerful politicians and administrators — people you are not supposed to criticize. On that topic, here is a video of Malcolm X talking about the danger of white liberals. Clearly he can hold his own in a debate without having a bias referee, and he makes some very good points about white liberals doing more harm than good.

Robert Buxbaum, November 5, 2017. In a related problem, black folks are arrested too often. I suggest rational drug laws. Some financial training could help too.