Total Pageviews

Friday, October 13, 2017

Carbon dating and the Math

One would have to be a hermit not to have heard about carbon dating.  This is the dating, for instance, of a piece of wood in an old building or a piece of charcoal in an archaeological dig.

At a first approximation, the physics is pretty straight forward.  An atom consists of a nucleus with electrons whizzing around the nucleus.  Which element the atom is depends on the number of electrons and the number of electrons, in turn, depends on the number of protons in the nucleus.  In a normal, unionized atom, the number of electrons and protons are equal and the atom is neutrally charged.

The glue that holds these positively charged protons together in the nucleus (remember like charges repel each other) are the neutrons.  Don't ask me how they do this.  The explanation is way above my pay grade.  Very roughly speaking, there are the same number of neutrons as protons but this can vary.  Carbon, for instance, can exist in a state with 6protons and 6 neutrons for an atomic mass number of 12. It can also exist in a form with 6 protons and 8 neutrons for a mass number of 14.

These two types are called isotopes of Carbon.  There is a third one but it is not needed for this explanation.

Some isotopes are stable, some are not (why is also above my pay grade).  In the case of Carbon, 12 is stable, 14 is not. 

Carbon 14 disintegrates into Nitrogen 14 with the ejection of an electron from one of it's neutrons.  The neutron becomes a proton so the atom is now a new element with 7 protons and 7 neutrons, hence 14N.

No one knows when any individual Carbon 14 atom is going to disintegrate.  There is a very small probability at any one moment but when you have a lot of 14C, you can predict how many atoms will change to 14N in any given time period.  This results in something interesting which has been observed experimentally.  If you know how much of the radioactive element you have, you will observe that half of it will break down in a given time, referred to as it's half life.  The half life of various radioactive isotopes varies from tiny fractions of a second to many millions of years.

In the case of 14C, it's half life is 5730 years give or take 40 years.

In 5730 years you will have half left, in another 5730 years, a quarter of the original amount, in one more half life, one eighth of the original amount and so forth.


So now we need the math for this.  We will work out what I call the straight forward formula and then we can change it around (solve for other parts) so that each component of the formula becomes the subject.

First a note on mathematical notation.

What is meant when you see a symbol.

xA means multiply the A by x.  If A is 2 and x is 3 then xA is 6

Ax means multiply A by itself x times.  If A is 2 and x is 3 then Ax is 8.  In words, A is raised to the xth power.

However, in the symbols Ax,  x is not an operator.  ie, it doesn't say to do anything.  It is a label.  It means the xth A.  For instance you could have A1, A2, A3 etc.  This is the first, second and third A.  Or Ao and At which for our purposes will mean A at time zero and A at a specified future time.

There is a special one in Chemistry.  I'll use Carbon since this is what we are talking about.  For instance 14C.  This means the carbon atom with 14 nucleotides.   ie, The sum of neutrons and protons adds up to `14.  There also exist 12C and 13C.  Of course both have 6 protons or it wouldn't be Carbon.  The number of neutrons varies.

And one more in Math.  If the subscript is after the word log such as log5 then it means log to the base 5.  If only log is used, it is understood it is to the base 10.   That is to say, log = log10 and if ln is used it is to the base 'e'.  Don't worry about it, we don't need 'e'.  I only mention it because it is on your little hand held computer and you might wonder.

Lets go back to the basics.  Every half life period, (h) the amount is halved. In the case of Carbon, the half life is 5730 years but half lives for other isotopes varies hugely.   Lets call the amount we start with as Ao (A at time zero) and the amount we are left with as At (A at some time t in the future).  The amount we will have left after one half life is:

1.   A1 = Ao(1/2)1

After two half lives
2.    A2 = Ao(1/2)2

After three half lives
3.    A3 = Ao(1/2)3
Remember 1/2 times 1/2 is 1/4.   Multiply once more by 1/2 and you have 1/8.  When you see a times sign between fractions, replace it in your mind with "of".  then 1/2 x 1/2 becomes one half of one half.

The 1,2 and 3 are the number of half lives that have gone by.

4.  So An - Ao(1/2)n  or in words, to find the amount of a substance after n half lives have gone by, multiply Ao, the initial amount, times 1/2 raised to the nth power.



Note that in the notation Ax,  x means the amount at time x expressed in half lives.

Also note that even if the n is not a whole number and therefore would take a wee bit of higher math (knowing logarithms), to solve, your computer does this with no problem.  Your high school computer can solve, for instance, 63.22 without raising a sweat.

Suppose we start with one gram of a radioactive substance and one half life has gone by.  We simply multiply 1gram times 1/2

Suppose 4 half lives have gone back.  We multiply the one gram times (1/2)4.  that is to say by 1/2 times 1/2 times 1/2 times 1/2 which equals 1/16th times the original amount.

Now suppose we know what the half life (h) of a particular isotope is.  Say it is 10 years, for simplicity.  Say 30 years have gone by.  Obviously 3 half lives have past.  In other words n, the number of half lives equals the time elapsed (t) divided by the Half life (h).  In this case n = 30/10 = 3.

5.   n=t/h.

And, as I said, it doesn't have to be a whole number.  If the half life is 10 years and 75 years have gone by then n = 75/10 = 7.5.  With simple math we would have a problem raising a number to a fractional exponent but your computer has no such problem so don't sweat it.

You can see where this is leading.  Since n=t/h, we can substitute t/h into the formula where we see n.

The radioactive decay formula then becomes

6.  At = Ao(1/2)t/h
or in words, to find the amount of radioactive material remaining after time t, multiply Ao, the initial amount, times one half raised to the power of t/h.


Good heavens!  I forgot to tell you where the radioactive Carbon comes from.  If it's half life is only 5730 years, in about 50,000 years there will be so little of it that carbon dating is out of the question and the world has been here for over 4b years.  Clearly, 14C must be being created somewhere.  the 'Where',, is in the upper atmosphere.  As cosmic rays hit the upper atmosphere, they are so energetic that they cause some nuclear reactions and one of these is to change 14N into 14C.  It is a very small amount but enough to be detected in living material with modern methods so we have a clock we can use.  When an organism dies it stops taking up carbon and the clock starts to tick.  If we  analyze it sometime in the future, we can know when it died (up to about 50,000 years).

Now we can do what a mathematician calls solving for Ao or for t or for h.  In other words we re-arrange the formula so that each of these terms in turn become the subject of the formula (ie. is by itself on the left and everything else is  on the right). I'll tell you what each variation of the formula is good for as we rearrange them.

The basic principle of solving for a factor (one of the letters) in a formula is that we can do anything we want to one side as long as we do the same to the other side.  After all if I have a formula that 7 = 3+4, if I multiply both sides by, say, 5, the formula is still correct.  Of course we don't just do random things to both sides of the formula. The trick is to do something that gets us closer to the solution we are looking for.

One other thing.  At one point in the procedure I am going to have to take a log of both sides.  Even if you don't understand logarithms, this should pose no emotional problem since I am doing the same to both sides.  Then, however, you are going to have to take my word for a 'log identity'.  If you are into logarithms, you will understand why the identity holds but if not, don't sweat it.  It is true.  This identity is:

logabc = clogab.  Incidentally, the inverse of the left side of this formula is ac =b.  That may give you a clue why the identity works.

In words:   log to the base 'a' of 'b' raised to the 'c'th power equals c times the log to the base a of b.

So let's start.  I want to end up with a formula for each of the terms, in turn, on the left side of the equation.

The original equation is

At = Ao(1/2)t/h

Let's divide each side by (1/2)t/h.  Note that this cancels out the (1/2)t/h on the right side and leaves it on the left.  It is more conventional to have the subject of the formula on the left so we will exchange them.  After all if 7 = 3+4 then 3+4 = 7.  Our formula then becomes

Ao = At divided by (1/2)t/h. Don't know how to get my computer to write this so I will leave you to write it down on a piece of paper.

Use
So what is this formula good for.  It was noted early on in the use of carbon dating that there were some discrepancies.  With artifacts for which the exact date was known, the Carbon date did not agree.  The hypothesis was that the rate of 14C production in the upper atmosphere might not have been constant over the years.  So cores were drilled into very old trees, the rings were separated and carbon dated.  The above formula was used to work out the concentration  of carbon 14 which had been present for each year  that a ring was laid down.  And indeed it was found that the true curve diverged by a small but significant amount over time from the theoretical curve.  When the true curve was used, the dates all fell into place.
 

Now let's work on t and h.  The first thing I will do is to divide both sides by Ao.  This cancels Ao on the right side and leaves us with

At/Ao = (1/2)t/h

Now I'll take the log of both sides

log (At/Ao) = log[(1/2)t/h]

Remember our identity.  I can take t/h to the front of the right side so

log(At/Ao) = t/h(log1/2)

Now it is simple.  I simply divide both sides by log1/2 and we have t/h by themselves on the right side.  You take it from here.  Isolate t and h.  If you do it right you will find that

t = [hlog(At/Ao]/[log(1/2)]

and

h = [tlog1/2}/[log(At/Ao}

Use
How about the formula for t.  This is pretty obvious.  Now that we have the needed correction of the production of 14C over the past , we can date any object that was once alive up to about 50,000 years.  This is carbon dating.

Use
How about h.  We can't actually wait around for 5730 years to see when we have half of a quantity of radioactive carbon left.  We can, thought, observe the rate of disintegration on a shorter time span.  Using the h formula we can work out the half life of each radioactive isotope and some of them are multi millions of years.

It is never that easy

There are always complications.  Charcoal, for instance, if it is in ordinary soils or even in a cave can be colonized by micro-organisms.  If in active soil, the micro-organisms will have a modern carbon signature.  One has to first clean the charcoal of the modern material in order to get the correct date for the charcoal

Add to that, that we have been spewing carbon into the atmosphere from fossil fuel.  This is old carbon and hence contains no Carbon 14.  On the other side we have had nuclear tests in the air.  They have added Carbon 14 to the air.  For future anthropologists, they will have to take this into account.

Other types of radioactive dating have their own special requirements.  For instance when a rock melt cools, crystals form and just as a solution of salt and sugar, as it crystallizes, will  produce crystals of pure salt and pure sugar, the  crystals in a melt are of one type of molecule.  If one of these is a radioactive species and it's end product is known you can measure the concentraton of both and calculate when the rock  was melted. 

Tuesday, October 3, 2017

The Anthropocene

This is a book review of William F Ruddiman's book, Plows, Plagues and Petroleum.  It's premise is that the Anthropocene* didn't start some 200 years ago with the beginning of the industrial revolution and hence the burning of fossil fuels but actually started 6000 to 8000 years ago.

* The age in which humans have started to have a significant effect on the climate

In the popular literature you will often find comments such as 'we live in a very unusual period.  Our climate, compared with previous times, has been remarkably stable for thousands of years'    That is not to say completely stable.  We have had the so called little ice age for instance and the medieval warm period but compared to the climate as read in ice cores, this has been a period of great stability.

Prof. Ruddiman basis much of this contention on information from ice cores.  In Antarctica, cores have been drilled which reach ice which was deposited around 800,000 years ago.  Over this period the alteration between glacial periods and interglacial periods* has had a cycle of about 100,000 years.  Here is a most amazing graphic of the past cycles.

* Note that I say glacial and interglacial period, not ice age.  Strictly speaking, despite popular usage, an ice age is the approximately 3m year period we are in with approximately 50 or so glacials and interglacials.  If we want to use the term ice age, for instance, for the time between the previous interglacial (the Eemian) and the present interglacial (the Holocene) then we need another name for the approx. 3m year period of alternating cold and warm periods that we are in the middle of right now.

What has caused these warm and cold periods has been pretty well established as the Milankovitch cycles.  There are three of these which have different periodicities.  There is the tilt of the earth  which varies between 21.2 and 24.5 degrees from the plane of it's orbit.  it is called Obliquity for some reason.  It's period is about  41,000  years.  There is the eccentricity of the orbit which varies from round to elliptical and back with a period of 100,000 years* and there is the orientation of this ellipticity in space which will result in the earth being closest to the sun in summer or closest in winter.  This has a period of 23,000 years and is called axial precession

It is a little more complicated than this.  For instance Eccentricity has a number of components.  It is not a simple sin wave but that will do for now.

Adding these three cycles together you get a variability in the strength of the sun on the surface of the earth and most important, in the mid to high latitude area of the Northern Hemisphere (where most of the land is).  To go into a glacial (glacial period), the insolation (Amount of radiation reaching the earth's surface) must be low in the Northern Hemisphere summer.  This allows snow to remain over the summer and to be increased during the next winter. Then the more land that is covered continually with snow, the more solar radiation is reflected back into space and we have a feedback which accelerates the process.  I won't go into how glacials end but you can go here and here for some ideas on how this occurs.

Over many many glacial-interglacial periods it has been observed that Carbon dioxide rises as the ice melts (some controversy on why) and a little before maximum melt, Carbon dioxide begins to fall.  Following this, with the odd up-tick CO2 falls continually.  At a certain level of Carbon dioxide, combined with the right part of the Milankovitch cycle, snow begins to accumulate, bringing on the start of the next glacial.

Since the Milankovitch cycle is the sum of three cycles, each with a different period, each glacial-interglacial cycle is somewhat different.  Looking at these cycles, the two which are most like the present one that we are in are the 4th and the 9th back from our present one.

In both these cycles (and in other less similar cycles) Carbon dioxide began to fall and just continued to do so, starting a little before maximum melt and falling to about 185ppm.

Our recent (Holocene) interglacial started some 20,000 years ago by definition since that was when the ice sheet was at it's greatest extent but melting really got under way about 11,500 years ago.  And as with all other cycles, Carbon dioxide began to rise.

Then, as usual, just before maximum melt, Carbon dioxide began to fall.

If it had continued, then at a certain point, snow would have begun to accumulate again.  Apparently the 'epicenter' of ice accumulation is on the high lands of Baffin Island and somewhat later in Labrador.  It didn't happen.  Around 6000 to 8000 years ago, the concentration of Carbon dioxide began to climb in complete contrast to other cycles.  It wasn't enough to fully counteract the downswing in the  Milankovitch cycle  but greatly slowed down the cooling.

It had almost reached the level for snow accumulation when there were two catastrophic events in human History.  One was the Black Death which scythed down huge numbers of people* in Asia, the Middle East and Europe.

It is often noted that this was the beginning of the rise of the rights of the serfs since they were in such short supply that they could demand better conditions in exchange for their labor.

The second was the invasion of South America by the Spanish.  The Spanish brought with them a plethora of deadly diseases for which the local population had no resistance.  Disease spread through south, central and North America and decreased the population*, by some estimates, by 90%.  In both plagues forests grew up on deserted farm lands and drew down Carbon dioxide below the level needed for the beginning of snow accumulation.

*Contrary to popular opinion, archeology has now confirmed that North America was populated by a large number of people, many of them living in what we would characterize as  advanced civilizations.

There is some very interesting evidence that glaciation  started.  Around the high lands of Baffin island there is a 'halo' of dead lichen with young new lichen beginning to grow here and there.  What happened?

Apparently, snow began to accumulate and last through the summer and occupy more and more area and of course smothered the lichen.  Then  along came the industrial revolution and the snow retreated again leaving this halo of dead lichen.  We were that close to beginning, once more, to slide into a glacial.

So what did man do to slow the advent of a new glacial for long enough for the Industrial Revolution to take over and really up the concentration of this green house gas.

First there was the burning down of forests to simply roast and catch animals. Areas burnt off, and especially if burnt off regularly, became grass lands which attract grazing animals and in which it is much easier to hunt.   In Australia, this probably started around 50,000 years ago when man first reached that continent.  Then as agriculture started, forests were cleared to plant crops.  An early technique was to simply ring bark a tree and then plant a fire at the base once it had died and dried out.  As the bronze age and then the iron age took hold, we could simply fell the trees.

Very soon after that, the plow was invented.  We have seen the tremendous damage the plow can do in modern times with the destruction of the soils of the great plains in America.  These were reservoirs of huge amounts of carbon which the plow released into the atmosphere.  If you travel through the Middle East you see clearly all the exposed rock.  The soils there have not only released their carbon but have been washed into the sea.  Farming with the plow is mainly responsible.

In the Far East the cultivation of rice in ponds was developed.  Anaerobic ponds give out large amounts of Methane which is a very powerful green house gas.  It oxidizes to the less potent Carbon dioxide and so stays around in a less toxic form.  This development reversed the methane trend.  Of course to build the extensive rice ponds, often terraced up the sides of mountains, you first have to eliminate the forests.

Sunday, October 1, 2017

Composting barns

I've just read an article on composting barns.  We are re-inventing the wheel but that is OK.  I saw this system in 1989 in South Africa and they had been using it for some time.  So what are they.  First a little background science.

You can classify the break down of organic material into simpler substances which are available for the growth of plants, into two main types.  This break down can occur aerobically or anaerobically.  The results are different.  With anaerobic break down, the processes are less energetic and two significant by-products are ammonia, NH4, and Hydrogen sulphide, H2S, (which in the air oxidizes to Sulphur dioxide and water.  SO2  H20). Both Ammonia and Hydrogen sulfide are gases and go off into the air.  In doing so, they  take with them the valuable nutrients Nitrogen (N2) and Sulfur (S). 

Aerobic processes are far more vigorous since the strong oxidizer Oxygen (O2) is present and only produce Carbon dioxide (CO2) and water.  In aerobic break down a whole ecology of microfauna build the available nutrients into their body mass. Aerobic processes can use cellulose and lignin as a source of Carbon and energy*.  In anaerobic processes, both are refractory. As long as the source of organic carbon lasts, the waste products are built back into body mass by the primary producers*.  Finally in this system, as organic carbon runs out, nutrients are released in a form that plants can use.  The ecology runs down and the final product left is Humus which has some interesting benefits for the soil.


*  In a photosynthesis system, the primary producers are plants.  In the sea, they are primarly single cell algae and sea weed.  In a compost pile they are micro-organisms and if the source of carbon and energy is wood (cellulose) then the micro-organisms which produce cellulase, the enzyme that can cut off the sugar mollecules from the cellulose are the primary producers.


In a composting barn, you provide a source of carbon in the form of saw dust or wood shavings. You could also use pelleted paper or any other source of cellulose.  Cellulose is an interesting substance.  It is a poly-sacaride.  In other words a chain of sugar molecules joined together in an insoluble form.  No multi-celled animal can digest this material.  Some bacteria, on the contrary, produce cellulase*.  While algae are the primary producers in the sea, cellulase producing micro-organisms are the base of the food chain  in a cellulose rich compost.

Enzymes are named for the substance that they can catalize the use of.  Hence the enzyme that helps metabolize sucrose would be called sucrase while the enzyme that metabolizes cellulose is cellulase.

Of course the cellulose is not enough for these micro-organisms.  They need the other nutrients such as nitrogen, phosphorous, sulfur and so forth to build their bodies.  They scavenge these from the environment and they themselves become food for a whole range of grazers who build these substances into their bodies.

As a rough rule of thumb, each level in the trophic chain can incorporate about a tenth of the material from the level below it.  A ton of phytoplankton can make a tenth of a ton of Krill which can make a hundredth of a ton of whale.  The remaining 90% at each transfer goes back into the soup to be used again by the primary producers.

As long as there is a source of energy, such as sunshine in the case of phytoplankton or cellulose in the case of a compost pile, all these nutrients are re-incorporated into biomass.  When the energy source runs out, there is a net release of nutrients as the various micro-organisms feed on each other but with no energy and Carbon source to power  the uptake of the released nutrients*

* This is why it is so bad to mix saw dust into your soil.  All the free nutrients will be scavenged until the saw dust is used up.  Then nutrients will be released and the plants can start to grow again.

So how about composting barns.  In these barns there are a number of requirements.  First, you need a thick layer of cellulose as bedding.  The urine and dung of the animals living in the barn (or visiting it) is absorbed by the saw dust or wood shavings.  The farm we visited in South Africa used the coarse saw dust from a saw mill.  But that is not sufficient.  The bedding must be kept aerobic.  In Africa, where I first saw this method, they were growing chickens.  This is possibly easier than growing cows because the urine of birds is almost solid.  Cows, by contrast, produce copious amounts of urine.  Labor in South Africa at the time was not expensive and the saw dust bedding of the chickens was stirred each day by hand.

In the case of a cow shed, one would have to have a mechanical method of stirring the bedding.  Cows go for milking and in some systems, go to graze during the day. giving a perfect time to aerate the bedding.

Note that the metabolism of all these wee beasties in the compost give off heat just as you and I do when we metabolize.  The bedding is warm and it has been reported that given a choice, cows will bed down in these barns in preference to staying outside or going into stalls with straw on the floor.

As you can imagine, ventilation is of the greatest importance as well.  No poisonous gases such as Ammonia or Hydrogen sulphide are given off but Carbon dioxide is produced.  A sloping roof with vents at the top of the slope and good access for air from the sides is vital.  The heat from the bedding and the not inconsiderable heat from the cows will create a natural convective circulation.  It is also useful to place the watering troughs outside the shed wall so that the cows can access it but so it does not drip down into the bedding. Moisture is needed for the activity of the compost bed but too much makes it very difficult to maintain aerobic conditions.

 Also useful would be to have drop down curtains, especially on the side where the heavy weather comes from so that rain can be excluded from reaching the bedding.

In really cold climate, one could employ a really large heat exchange ventilation systems which uses a counter flow system to pass outgoing air past incoming air to keep the heat while exchanging the air.  Such systems are used on as smaller scale in air-tight houses today.

When we talked to the farmer in South Africa who was using this system for Chickens, he mentioned as an aside how disease free his chickens were under this system.  Apparently any pathogens that fall into the bedding are on a hiding to nothing.  The environment is inimical to their survival and they are destroyed by the rich fauna of composters.  Another article I read on cow sheds using this system emphasized the same phenomenon.

To recap, what are the benefits of this system.

* Animal welfare.  The very fact that cows vote with their feet and choose to bed down on the compost in preference to staying out in the cold or going to a straw lined stall shows how beneficial such a system is.  It is highly likely that in such a system, the amount of milk per unit feed would increase as the cows are using less energy to keep warm and are less stressed.

* Nutrient retention.  All the nutrients from the waste products of the cows is held in the compost to be later used to enrich the soil of the farm.  Nitrogen and Sulphur do not go off as gases to be lost to the farm.

* Odor control.  The smell of a well aerated compost is faint and pleasant in great contrast to an anaerobic compost.  The neighbors are not annoyed.

* Disease control.  There are strong indications that diseases are reduced with this system.  It is likely, for instance,  (though not yet reported on) that mastitis would be reduced when the cows bed down on a compost bedding.

Monday, September 4, 2017

Getting into orbit

Disclaimer:  I  ain't no rocked scientist.

But it seems foolish the way were are getting into orbit.  I understand why Elon Musk is going this rout.  He wants technology that is capable of landing on Mars using it's rockets. Returning rockets to earth this way, as he is doing, is a good test ground for eventually landing on mars.  But for others, who are sending payloads into orbit, it seems pretty costly and inefficient.

Very likely I am wrong.  My calculus is rudimentary and I base the following on simple (high school) physics a touch of Skunk Works philosophy*

*The Skunk works  buys everything it can off the shelf and only innovate those parts of a system needed for the particular function it wants to achieve.  They are consistently within budget and beat deadlines.

Why Calculus?  If you want to calculate how far you have gone in a car traveling at a constant velocity you just multiply velocity times time.  For instance, traveling at 50km per hour for two hours, you travel 100km.  Sending a rocket into space gets a tad more complicated.

You have a slightly decreasing gravity as you go into near earth orbit, a rapidly decreasing fuel and oxidizer load as you burn off fuel, a decreasing air resistance as you get higher  but an increasing air resistance as your speed increases.  Calculus allows you to combine  these and other constantly varying factors to ultimately work out, for instance, how much fuel you need to get a given payload into orbit.

While we are talking about complications, there are certain restrictions you have to observe.  You can't accelerate too fast or you may damage your payload (people and instruments).  You also must not achieve too great a speed too soon.  If you do, you will burn up the outer skin of the rocket.  The Black bird, for instance, cruising at an altitude of  85,000ft (16 miles)  at Mach 3 (three times the speed of sound) has it's outer skin heat up to about 300degrees C.  The only reason it survives is that it's skin is made of Titanium rather than an alloy of Aluminum.

This introduces another problem into the mix.  Sometimes it is useful to go to the extreme limit of a problem to get an instinctive feel for it.  For a rocket to get into space it needs it's energy to overcome a number of factors.  It must provide enough thrust to equal the weight of the rocket.  More is needed to accelerate the rocket.  For every kg of rocket weight it lifts by a meter, a kgm of energy is needed (9.8 joules).  More still is needed to overcome air friction.

Lets go to the extreme case and take a rocket that provides just enough thrust to hold it in position.    It is not gaining altitude.  It is expending energy to no useful purpose and the amount of energy equals the rate of energy being expended multiplied by the time it remains stationary.  From this you can see that the faster it accelerates, the less total energy it will need just to support it's weight.  The less energy that is wasted just supporting it's weight, the more energy goes into acceleration.  However the above restraints limit how fast it can accelerate.  All this means it needs more fuel.  Remember this analogy.  It will become important a little further along.

Most rocket ships use an oxidizer, often oxygen itself and a fuel which is often Hydrogen.  Already we are courting disaster.  You either have to hold these gases at very high pressure to have enough on board to do the job or at very cold temperatures so that they liquefy.  In both cases you need very special tanks that weigh a lot compared to the sort of tank that you have in your car for gasoline or diesel fuel.  The high pressures or extremely cold temperatures also cause problems.  If we could get rid of this sort of fuel and oxidizer we would be far better off.

So what is the solution.  Take the first stage of your rocket and strap on four, off the shelf, 747 turbo-fan engines.  The PW4000 develops just under 45metric tons of force.  So four of these = a little under 180 tons.  Lets call it 150 tons to be conservative. Perhaps better still, use blackbird engines which can work at very high altitudes. In either case you are now using the air as an oxidizer just as all jet planes do and your fuel is the relatively benign jet fuel (very similar to kerosene or diesel fuel).  look at the range of these aircraft.  Just on the fuel in their wing tanks, a 747 can fly a third of the way around the globe at around 30,000ft.  Pretty impressive, no?

On second thought, there might be a third type of engine that I am not familiar with that would be better than either of these two.  The regular 747 engine is designed to work best at around 30,000ft and the Black bird engine to work at super sonic speeds.  What we need is an engine that will work at subsonic speeds at very high altitudes.

Whatever engine you decide on, suppose that you don't have enough thrust now to send your rocket straight up.  Lets strap on a pair of wings and take off from a runway.  The shallower the angle of take off, the greater the load for a given amount of thrust.

Why the wings.  Not only do they allow you to lift payloads far greater than the thrust of the engines but also with far less fuel.  Once again an example is useful to get a feel for the problem.  Picture a 747 at cruising altitude neither gaining or loosing altitude.  The thrust it needs and hence the rate of fuel use is far less that if it turned its nose upward and just hung there on its engines.  With or without wings, you still have to lift x kgs up to y meters but the wings, to a large extent support the weight of the payload without needing this huge extra thrust just to support the weight.

So where have we got to so far.

Basically we have a stripped down 747, possibly with a modified wing for lift at high altitude and suitable high altitude engines.  So how much weight have we eliminated.  A 747 can carry 660 passengers in a one class configuration and very conservatively, each passenger weights 100kg.  That is 75kg per person plus 25kg of baggage.  As I said, this is very conservative.  The load carried is therefore 66000kg or 66 tons and we haven't even considered the freight they carry independent of their passengers and all the fittings inside the fuselage needed to accommodate their passengers.  I don't know how much this would amount to all told but it is considerable.  Probably around 100 tons for passengers, freight and all the fittings the passengers require.

So how do we carry the second stage (the first rocket stage) up to high altitude to be launched.  We have three choices.  We can sling the rocket under the plane, carry it on top the way they did with the shuttle when transporting it back to be refitted after it landed or we can carry it inside the fuselage.  The two outside options probably require some reinforcing for the contact points.  The inside option necessitates a bomb bay or an opening ceiling such as the Shuttle had.  As odd as it seems, carrying the rocket on top might be the preferred  option.

So how do we launch.  The mother ship flies toward the equator where the maximum earth rotation boost will be obtained (about 1000mph) gaining altitude as it goes.  When at maximum altitude it turns to face East so that it is traveling in the direction of the earth's rotation.  It puts on full power and does a vomit comet maneuver.  That is to say it pulls up into a parabolic curve at zero gravity or even a slight negative gravity.  At or before the peak, the second stage (first rocket stage) detaches and fires it's rockets.  The mother ship veers out of the way of it's rocket blast.

At this altitude we have lifted the weight of the second stage up, say 100,000ft, gone through by far the greatest part of the atmosphere and given the second stage a speed of, say 1500 mile per hour.  We might be able to get away with some of those off the shelf solid state rockets and further eliminate the problematic hydrogen and oxygen.  Initially, a couple of small canard nose wings might be sufficient to maintain direction.  In the vacuum of space those little nose rockets would maintain direction.  We need to achieve about 18,000 mph.  The solid state rocket shells might then be cut loose or alternatively, they could be configured on the ground to be a useful component for the construction of a space station.

The converted 747 flies (mostly glides) back to base.  It can have another rocket attached be refueled and be back at the launch point  in a few hours.  We could probably launch 4 or 5 rockets each day this way from a single mother ship.

We need costing by professionals far more qualified than I am but it just seems to me that we could get payload into orbit far cheaper than we are doing today.

By the by, whatever happened to the idea of building a space station in the form of a bicycle wheel.  With the appropriate spin, there would be one G at the rim and the astronauts would cease to have the weakening of their muscles and the wasting away of their bones.  If you want to play around with some figures, centripital acceleration equals the square of the peripheral velocity divided by the radius of the circle.  Put this equal to 9.8m per second squared and you can work out the details of your space station.

Electric VW combi, bulli, mini-van

VW is finally going to give us the electric Combi.  Fantastic, but they must keep the faith.

The original Combi was iconic for a number of reasons.

* It was simple compared to other vans.
* It was easy to work on - easily repaired
* It was affordable
* It didn't change its styling from year to year.

It should be not only possible but really easy to produce an electric Combi that excels in all of these.  Styling is simple.  Once it is designed simply don't change it.  This is a vital factor in making a car become iconic.  It also allows better pricing.  It is expensive to re-tool your body presses each year.

Electrics by their nature are far simpler that petrol cars.  Make very very sure that everything that might have to be done on the car is very simple to do.  The engine should be removable by undoing 6 nuts and sliding in a new or reconditioned one.  Batteries should be exceedingly simple to replace (for instance when new technology results in an even better battery).  CV joints should be doable by a modestly competent home mechanic and so forth. Go over the rest of the car (exclusive of the propulsion system) and make sure every part is easy to work on.

And don't put in everything that bumps and squeaks.  We are not looking for luxury in the combi.  Just a good ride in an affordable vehicle which has great range and is inexpensive to maintain.  At the very least, make all the flash options just that.........options.

If your engineers simply can't resist a challenge than get them to work on  a way to clad the whole roof with solar cells such that they all give their full power despite not being co-linear or being partially shaded.

No one expects to be able to drive only on solar.  That is unrealistic but what a nice bonus and a way to get you out of trouble if you have ignored the charge of your battery.  It happens.


Keep the faith and you will sweep the market.   Such a car is not for everyone but many of us want to have a smaller footprint.  Many of us want a car that we are proud to drive.

And for #@%^&; sake, don't make it self driving.  We like to drive.  Besides we don't want to be spied on all the time or worse still have our vehicle hacked and therefore come under the control of  someone else.  Even worse, we don't want the various secret service organizations to be able to decide to drive our car over a cliff or into a tree.  In short, we don't want our car even to be connected to the WWW.

Saturday, August 26, 2017

Restoring our soils

This is a book review of David R. Montgomery's book, Growing a Revolution; Bringing our soils back.  I highly recommend the original.  Besides being a real eye opener, it's a good read.

Items in italics are my responsibility.  Not to blame Prof Mongomery if there are any mistrakes.

If you prefer, here is the author talking about the book on Youtube
https://www.youtube.com/watch?v=c4p-kQ6D8aA

Prof. Montgomery has traveled the world and documented the work of farmers far and wide who are using these techniques with amazing results.  Even more amazing is that when there is one of these farms right beside another which uses "conventional methods" and the difference in production is blindingly obvious  even at a casual glance, these so called conventional farmers who are using large inputs of agricultural chemicals, very often  stick with their methods.  Prof Montomery suggests why this is.

In his book you won't find reports of great research done by the agricultural departments of universities.  No university can afford to do the research that has led to these methods.  As the world becomes more and more of a corporatocracy, and multinationals find ever more inventive ways to avoid taxes, government funds have dried up and almost the only source of funding remaining is from these same tax avoiding companies.

No company is going to fund research that leads to less  of their products being used.  If, for instance, a universities agricultural department is being funded by a producer of Phosphate, they will think twice before even having an independently funded research project on site that will show that you can reduce or dispense (for a time) with more additions of phosphate.

This type of farming mentioned in the book, leads to  a greatly reduced use of fertilizer, pesticides, herbicides and fuel. Note I said reduced, not eliminated.

What is reported in Growing a Revolution is the work of many farmers around the world, usually with no connection with each other.  These farmers would qualify, by any definition, as true scientists, trying things and recording their results and trying again.  There are variations on a theme but what is also amazing is that all these farmers have converged on the same basic realizations.  It has taken many of these farmers decades to come to these methodologies.  Mr Mongomery's book is an attempt to smooth the way for other farmers so they don't have to go through the same lengthly process.

What then does Mr Montgomery claim that this sort of farming achieves.  Actually, I should rephrase that.  What has he observed that farmers around the world are achieving with these methods.  And notice the emphasis on methods in the plural.  While each method shows some positive results, these methods only truly revolutionize farming when used together. First the results of this type of farming.

Results of this 'new'  type of farming


#  Reduced  inputs including diesel, chemical fertilizers pesticides and herbicides resulting in greater profits even if yields only match "conventional*" farming.  In fact, yields more often than not, rapidly (in a few short years), exceed those of chemical farming.  Profit equals production minus inputs.

* We now think of farming with chemical inputs as conventional since we are used to seeing this type of farming but it is actually a very new way of farming. When we get on to methods, you will see that many of the methods are very old school but modified by recent insights into the biology of soils. So called conventional farming necessitates large amounts of fossil fuel (in addition to the fuel to run the tractor).  Reducing these inputs has to be a good thing from a number of points of view.

#  Increased infiltration of water into the soil and the  corollary, reduced or eliminated  surface run off, thus stopping the export of our soils into the ocean. The other corollary of more infiltration, especially with reduced evaporation is less dependence on irrigation and in the case of dry land farming (without irrigation) the difference between a crop and no crop.

#Greatly reduced export of  soil into the streams if there is a "weather bomb" and runoff does occur.

# Elimination of wind erosion

#  Greater drought resistance since rain has infiltrated and soils are always protected by a cover crop and/or mulch, which decreases evaporation.

#  Greater flood resistance for the whole catchment since the soils can take up much more water without sending it straight down into the nearest water way.  If a whole catchment of farmers adopted these methods, flood peaks down stream would greatly decrease and with it, a decrease in damage to downstream property since once the water is underground, it flows much more slowly toward the sea. Not only are peak  flows  reduced but low water flows are increased as this water slowly percolates back into the river systems.

# Water purified before flowing into the streams.  When water flows through a rich organic soil, the fauna of the organic soil scavenges nutrients from the water, reducing the amount of P and N entering the streams.  In addition, pathogens don't have a chance when they enter a rich soil ecology.  

#  Holding nutrients in the soil in a form which is accessible to the next crop rather than exporting them to the nearest stream via the ground water. Streams flow clear again and if adopted widely, dead zones at the mouth of rivers would be a thing of the past. As a result, aquatic life in the streams recovers and salmon and trout prosper.

#  Greatly decreased or eliminated weed problems despite the use of no-till agriculture and reduced or eliminated use of herbicides.

#  It is believed here in New Zealand that on well drained soils, when a cow urinates, it goes right through the soil into the water table and hence into nearby streams. Organic material is a sponge which will soak up liquid, whether water or urine.  If the organic material increases, not only at the surface but also at deeper and deeper levels of the soil, so much the better.  The following methods increase organic material throughout the soil, shallow and deep.  Once the liquid is held in the soil, the fauna in the soil scavenges the nutrients from it.

So what are the methods David has observed which are creating this revolution.

Methods

You may have noticed that I have called this a new way of farming.  As I mentioned it is not new methods but the adaptation of methods which were used before the advent of chemical inputs but  with a modern twist in light of modern knowledge. These farmers still use chemical fertilizer where necessary.  This so called 'conservation agriculture' is not a religion but a pragmatic approach to farming.

Crop rotation
Sound familiar??  .  No surprises here except he has observed farmers who are using a better way of crop rotation.  If you only plant wheat, this is the worst case scenario.  If you rotate wheat and, a legume in alternate years, this is better.  If you adopt a three way rotation of, say wheat, corn, soy beans, better still but the best system is to rotate as many different crops as is practical and in random time patterns.  This type of rotation confounds the pests.  For instance use wheat barley and oats as your grain crops interspersed with soya, corn and peas.

Many pests are crop specific.  Planting the same crop in the ground year after year allows them to build up in the soil.  Even alternating crops in a two crop system will cause the pests to adapt to this simple system.  You develop a nematode or stem weevil, for instance, that can hold out for a year until the favored crop is returned to the field. A more random schedule of rotation and longer times between the same crop is very hard on crop pests. 

Cover crops
As soon as the summer cash crop is harvested, a cover crop is sown.  In locations where there are harsh winters, this crop will be killed by the frost.  In warmer climes, it is rolled into the soil before it sets seeds*.  The frost killed cover crop is rolled into the ground in the spring in the same pass in which the cash crop is planted into this bed of mulch. The best candidate for a cover crop is a mix of 8 or more different species including:

   * The most effective roller he has seen has projecting steel flat bar in a chevron or diamond pattern.  It chops up and pushes the cover crop into the ground.  It all can be done with one pass of the tractor as the cover crop is rolled into the ground and the next cash crop sowed right into the mulch layer created. The cash crop comes up and shades the soil and any weeds that remain. As the years go by, weeds become less and less of a problem.
 
Plants in the cover crop include:

# a deep rooter to scavenge nutrients from down deep and to provide a root system that as it decomposes, leaves passage ways for water and air to reach deeper levels.  This decomposing organic material will also hold water better than pure mineral soil, making it available to future crops.  If cows are grazed on the fields, there may be a problem with their large urine output.  If it goes down into the soil into the ground water it can flow to the nearest stream.  With lots of organic matter, both shallow and deep, the liquid is soaked up giving the microbiome time to convert this source of Nitrogen* into biomass.

* We had a major kerfuffle here in New Zealand about indoor farms.  As usual the greenies went off half cocked and dismissed them out of hand.  I don't say that indoor farms are always good for animals.  Some can be really horrific.  The devil is in the detail.  One advantage of wholly or partial indoor farms is that you have almost complete control of the waste products that can then be applied to the soil when and in what quantities are most effective and hence less wasteful.  In this connextion see Composting barns.

# a shallow rooter to provide a root network holding the surface soil together and a source of organic carbon and nutrients as it slowly decomposes.

# a nitrogen fixer to add nitrogen to the soil

# a nitrogen user (as virtually all plants are).  They scavenge the left over nitrogen to be released gradually next season as they decompose.

# a tuber (radish for instance) which as it decomposes leaves large tunnels in the soil for water to percolate down into the soil.  The decomposing tubers feed the soil life and adds structure to the soil.  Many tubers have very deep roots as well.

A common function of all these cover crops  is that they exude high energy materials from their roots into the soil.  These feed the saprophytes.  Saprophytes not only give structure to the soil but  are able to mobilize nutrients that are not available to plant roots and convert them into a form that the plants can use (notably P).  The exudates also feed the microbiome which are in turn consumed by earth worms.  The worms themselves are a link in mineralizing* nutrients into a form that can be used by plants.  In addition, they make burrows which  increases water infiltration and allow oxygen** to reach the roots of the plants.

Green plants don't use organic matter.  It must be broken down into a soluble, mineralized form that dissolves in the soil water.  Plant scientists call this process mineralization.

** Very few plants transfer oxygen from their leaves to their roots.  Most need air around their roots to survive.  Worms also provide this service.  Incidentally, if you dig in soil that has been regularly plowed for years, you will be hard pressed to find any earth worms.  After a few years of this type of farming, worms will be back in force.

Different areas will need different mixes of cover crop species.  This is a rich area for research in working out the best mix of species for specific areas.

No Till
David observes that the plow back into antiquity has probably been the main cause of the destruction of soils.  This is very visible in areas where the Greeks and the Romans held sway.  More recently it destroyed the soils of the great plains in America.  We mustn't be too hard on the plow, though.  It may be part of the reason that we haven't already headed into a new glacial period due to the huge amount of carbon that was released from the soil into the air*.  Now we have found another way of keeping atmospheric carbon up and can afford to adopt methods that return the carbon to the soil.  We are now in danger of going too far the other way and putting far too much carbon into the air for our own good. Sequestering some of this into the soil would be a good thing.
*See the fantastic book by William F. Ruddiman, Plows, Plagues and Petroleum

No plowing is done.  At most a very shallow groove is made in the soil to plant the seeds and if chemical fertilizer is used, it is placed in small doses near the seeds, not broad-casted over the whole field.  Farmers who are adopting these methods are finding that much less or sometimes, no chemical nutrients are needed.

Phosphorous, for instance, in their fields is mobilized from the locked up P in the soil by saprophytes and Nitrogen is scavenged by the cover crops and held in a slow release form (their bodies) for the next cash crop. It is also supplied by the nitrogen fixer in the cover crop.

 This doesn't mean that no chemical fertilizers are ever used but they are used as needed.  If, for instance, your soil was found to be deficient in, say, cobalt, clearly you would apply a  cobalt fertilizer to provide for your plants and/or animals.  This is not organic farming or so called 'conventional' farming.  It is conservation farming.  It is not a religion but a  science in which you do what works.

Clearly, if you are continually removing crops from your land, you will need at some point an input of the removed elements.  There is nothing wrong with using chemical fertilizers but you don't want your phosphorous and other nutrients to be continually locked up by the soil in a form that the plants can not get at.  This is expensive.  You also don't want your nutrients to seep down below the root zone and be washed into the nearby stream.   Nitrogen can be provided from the air by a nitrogen fixer.  Your input of chemical fertilizer is hugely reduced and is applied only as it is needed.

Often, in soils where super phosphate has been used over the years, the soil has a huge reserve of Phosphate but it is all locked up.

The above are the three main methods, namely no till, cover crops and random crop rotation.  In addition there are two more where appropriate.

Grazing
Again not a new system but an old system with a new twist. It is used by some of these farmers. Both crop stubble and cover crops can be grazed and turned into manure and urine which is very good for the soil.  If grazing is used, no roller is needed.  Some of the vegetation is trampled into the surface of the soil which acts as mulch and provides food to feed the microbiome.  The system, though, that seems most successful is to graze very hard, very infrequently.  Cows, for instance are put on a paddock at a density that finishes all the fodder in in one day and then not grazed again for a year.  This system may have been inspired by a TED talk by Allan Savory on his work in Africa.  This TED talk is a revelation in itself.

No farm, however, can afford to break the farm into 365 small paddocks with fences.  Instead mobile electric fences work very well to allow cattle access to a limited area and exclude them from both the as-yet-to-be-grazed area and the already-grazed area.  One uses a front and a back electric fence. Many farmers in New Zealand already use this method.  There may be places where you would let the grazers in more than once per year but the same principle still holds.  Very heavy grazing very infrequently.

Terra Preta 
In warm areas with soil above about 25 degrees C, humus which holds nutrients and gives structure to the soil, breaks down and goes into the atmosphere unless taken up rapidly by, say, an overlying jungle.  When a tropical jungle is cleared, at most a couple of crops can be grown before the soil is exhausted and the farmer than resorts to chemicals which  finish the damage.

It has been observed, though, that there are exceptionally good soils in some tropical areas, often along major rivers.  These are areas where the locals have incorporated char into the soil from partially burnt bones and plant material.  Char has a three functions.  It has no nutritive value to the plants what so ever but it does provide nitches  where the microbiome can live*.

* The organisms in the micro-fauna of a soil often live in colonies attached to a substrate.  They are not free living like, for instance, phytoplankton in the oceans.  Charcoal provides ideal surfaces and hidy-holes for such organisms and lasts for centuries in the soil.

If you raise chickens you may be familiar with something similar.  If you have a lot of chickens in a yard, before long they will have eaten every bit of green that they find at all palatable.  So you set up a bunch of cages and plant their favorite green inside.  They can only get to the outside leaves so as the plant grows, the chickens crop off the outside but the plant itself is protected and continues to provide greens for the chickens.  Charcoal is very porous and in the soil serves a similar function.

Charcoal, though, has another function.  It can adsorb nutrients on its surface when they are available and release them when in low concentrations in the soil.  Char with respect to nutrients is a little like the hemoglobin in our blood with respect to Oxygen.  In both cases the substance in question is taken up easily when available and released when not.  In cooler climes, humus serves this purpose.

Char is probably not a practical option in commercial farming until  and unless we start producing it in large quantities at a feasible price.  One good thing, though about char is that it lasts for a very very long time in the soil.  In a home garden, it is very practical.  All you need to produce char is a 45gal drum.


Note:  I have just read an article on composting barns by Keith Woodford. This technology would fit in exceedingly well with what Prof Montgomery has reported on.  Composting barns capture all the nutrients, including nitrogen, contained in the waste products of the animals,  grown in the barn.  Spread back on the land, this would further reduce inputs from outside the farm. 

Addendum

Carbon credits

If the government is playing fair with farmers, the farmer should be able to receive a nice carbon credit for switching to this type of farming.  What is first needed is a survey of your farm to determine what is the carbon content of your soil before you change your methods.  You can do this yourself at home if you have a reasonably sensitive balance.  If I remember my chemistry, the procedure is something like this.


You take a sample of soil, preferably with a corer or a post hole digger that goes down to mineral soil.  You note the depth to which you took the sample and the area of the surface of the core.  A = πr2   (pi r squared)

Thoroughly mix the soil and take an appropriate size sample.

Treat the soil with an acid such as HCl or H2SO4 (battery acid).  This converts carbonates to Chlorides or Sulphates.  Otherwise, when you heat the soil later, the carbonates convert to oxides and it looks as if you have more organic matter than is actually in the soil.

You dry your sub sample to constant weight at just over 100 degrees C.  ie, you dry it, weigh it, and dry it again.  If the weight remains the same, you go to the next step.  If not, dry again until two subsequent weights are the same.

Put your sample in a porcelain type container that has been dried and fired to constant weight and heat it in the oven to about 500 degrees C.  Start in a closed container but finish with the container open.  You can get appropriate containers from any chemical supply shop.

Burn to constant weight.  The difference between the start and the finish is the amount of dry organic matter in your soil. Very close to 50% of this is carbon You can then calculate the amount of carbon in the upper level of soil down to the depth you cored.  You can also work out the percentage in your soil and the carbon content per hectare.  If you want, you can convert this to the Carbon dioxide equivalent by multiplying by 44/12.   This is the amount of Carbon dioxide you have sequestered from the air.

Saturday, June 17, 2017

Self driving cars



Are we really sure that we want self driving cars.  In fact, are we sure we want a car that is even connected to the Internet.  There are some pretty strong arguments against both self driving cars and against cars which are connected to the Internet (done so that software updates can automatically be fed into the car computer).

Just recently there have been some pretty serious hacks.  The NHS (National Heath service of the UK) was taken down and here in New Zealand we just had a program on our National Radio about the hacking of electrical power line companies.  You would have thought that if there were systems with the very best of protection, it would be these.  Perhaps they did have excellent protection but were hacked anyway.

Update  Today (17 Oct 2017) WiFi was hacked.  Sheeeesh!!

Imagine the chaos if we had even 10% of our cars connected to the Internet when someone managed to hack the system.

Then there is the secret services of the United States and the so called 5 Eyes.  In America it is illegal for these institutions to spy on American citizens but they do it anyway.  The  hoover up every phone call and e-mail from America and from the rest of the world.  Even having a car which is connected to the internet, never mind self driving, gives these institutions yet another window into the private life of all of us.  And don't give me the argument that if you are not doing anything wrong you have nothing to fear.  That argument is so discredited that it doesn't even justify wasting a paragraph explaining the  fallacy.


Suppose, for the sake of the argument I want a new software program for the electric car I am driving and my car is not on the internet.  No problem.  I will go to my home computer, download the upgrade on to a flash drive, take it to my car and plug it in to the flash drive socket provided.  Besides, I may want to wait a year to let the early adapters test it out before installing it.  The computer world if rife with new computer programs being full of glitches.

Suppose I need navigation.  I will simply take my cell phone and put it on the Velcro patch on the dash board.
.
As for self driving, let me ink out a scenario for you.
.
You have a daughter - the apple of your eye.  You insisted that she learn to drive on a gear shift car since you are a little old fashion and value the old skills.  However since she got her license, she has never driven.  You gave her a self driving car for her birthday and she loves it. (no wonder) Today she is off to a show in the next town with her boyfriend.  ETA 30 minutes.  What do you think she is doing for that half hour.  

She is snogging in the back seat with her boyfriend going at highway speed  when some sort of computer glitch or hack demands that she take the wheel and manage the brakes and accelerator.  It would be chaotic enough if she was sitting in the drivers seat with her hands off the wheel.  You fill in the rest.

Add to this the ability the secret services will have to send a car into oncoming traffic, over a cliff or into a tree.  You think I am exaggerating.  Look at the drone programs exposed by Manning.  They took shots at a suspected terrorist while he was surrounded by civilians.  Secret services are amoral and we don't need to give them more tools to do what they want.  What's that you say?  They don't operate on their home soil.  Give me a break!!!

And one further point.  With self driving cars and trucks, we put yet another tranche of workers out of work.  These are folks that will never be engineers, scientists or lawyers and we need work for them as well.  Economists seem to always ignore one basic fact of the economy.  The most important factor is the rate that wealth circulates through the economy, not the amount of dollars available.  Work through the implications (already demonstrated) of putting yet more people out of work.

It simply leads to wealth being more and more  concentrated in the hands of the very few uber rich and less circulating in the economy.  We are rapidly getting to the point that less and less people will be able to buy the products produced in the factories.  One good effect of this is that it cuts into inflation.  That may help to explain our present situation (2017). 

I have a strong feeling that an electric car manufacturer who advertises that his cars are not self driving and have no connection to the Internet would have a strong selling point.

Thursday, June 8, 2017

The folly of GM crops

I'm not going to go into various esoteric subjects such as the chance of human created genes jumping to other unrelated species or the chance of wiping out whole species which we consider pests but who's function in their ecology we don't fully understand (possible with CRISPR).  This blog looks at the folly of past agricultural advances and the harm they have caused and hence the folly of increasing food production even more.

Despite the propaganda of the large companies promoting GM crops, their aim is not to relieve human suffering and provide food for the starving masses. (surprise surprise)  It turns out that we already are producing enough food to feed everyone in the world quite adequately.  Their aim is to accumulate more of the wealth of the world to themselves and is just one more manifestation of the growing wealth inequality that we see everywhere.

 As they accumulate more of the world's wealth, the very people they say they are working for become poorer and less able to afford to feed themselves. So what are the down sides of producing more food.

Malthus, the much maligned, stated that populations increases exponentially; ie 1,2,4,8,16 ......, while food production increases arithmetically; ie 1,2,3,4,5 ...... In reality, populations such as humans which lack predators are limited by starvation. A possibly more useful way of stating the principle, with apologies to Parkinson is that Population expands to use up any advance in food production*.

Richard Dawkins on P391 of his excellent book The Greatest Show on Earth stated it succinctly and I quote.  "If there is ever a time of plenty, this very fact will automatically lead to an increase in population until the natural state of starvation and misery is restored."  One would hope that humans who, at least individually, show a modicum of foresight might learn to show collective foresight.

Malthus didn't count on various technical advances we would make in food production ever since we left the hunter gatherer life style but was completely correct. Each increase in food production has been used up by population increase. The recent, much vaunted green revolution which started around the 1960's was the latest of such jumps in food production and gave India and some other countries, a few decades without starvation. A recent estimate is that there are now 700m more people on earth due to this latest green revolution.Link
So with a few delays, Malthus has proven to be completely correct.

What he didn't know is how our knowledge of contraception would advance. It has often been observed that when populations reach a fairly high level of economic well being, birth rate falls. Everyone is mystified by this and explains that women are delaying having babies as they pursue a career; people are not having any children so that they can enjoy the fruits of their labor and so forth. 

No argument there but how do you think they are avoiding having children. Abstinence??? I don't think so!! Abstinence went out of fashion more than half a century ago. One of the reasons for not having children (not often stated) is so you can enjoy non-abstinence uninterrupted. The simple fact of the matter is that with a certain level of economic development, contraception becomes affordable. 

The proof of this is a number of countries which have made contraception affordable before they achieved a western level of development. They did it by subsidizing contraception and lo and behold their birth rate fell. Of course, with birth rate under control, per capita economic development is much more likely. There are less mouths to eat up  advances in productivity.

While we are at it, lets look at the most recent  green revolutions that began in the 60's. The Yield of a number of grain crops was greatly increased. Some reports say production was tripled. This production was achieved by careful selective breeding but the new varieties only fulfilled their potential with irrigation, fertilizer, herbicides and  insecticides. Despite being free of starvation for a number of decades. the change was not an unmitigated success. Part of the dark side has been:

   a) mining of the water table to provide water for the new, highly productive varieties, lowering it disastrously, notably in China and India,
   b) accessing deeper layers of water which are contaminated with arsenic, notably in Bangladesh and parts of India,
   c) Pesticide pollution of aquifers, which along with arsenic contamination has led to a greatly increased incidence of cancer, especially in Bangladesh and parts of India
   d) salination of soils, rendering them unfit for agriculture.
   e) more land in production pushing nature and her free provision of food, fuel, fiber, medicine waste disposal and clean water further into a corner*.

*(you would have thought that land would have been taken out of production due to higher yields.- go figure)

   f) production of greatly increased grain yield but with less vitamins and minerals per kg of grain than in traditional varieties resulting in nutrient malnutrition,
   g) huge loss of a genetic diversity as locals switched to the new varieties, abandoning their traditional varieties.
   h) the loss of small farms to large land owners as the peasants borrowed to buy fertilizer etc., got into debt and defaulted on their loans.
   i) an increase in population of about 700,000,000 mouths that are only with us because of this most recent green revolution.

We really have got to the point of diminishing returns. Every advance in agriculture production makes us poorer and poorer. It makes us poorer by:

*decreasing the availability of food, fuel, fiber, clean water and clean air that we obtain gratis from nature as more land is put into agriculture for profit.
*decreasing the ability of nature to process our wastes safely
*decreasing the variety of foods available to us as areas which once grew fruit and vegetables are given over to the more profitable growing of grain crops for cash.
*reducing the space we have to live in as we are crowded by more and more people.
* facilitating diseases of crowding that we would otherwise not have had and increasing the possibility that a pandemic will be much more severe.
* pushing us closer to a disastrous collapse in our Gia support system as we test the theory of sudden climate change with gay abandon.

There is talk now of the need for a second (actually more like the 100th) green revolution, this one based on splicing new genes into varieties of grain. This will probably work and will further increase production. As has happened since agriculture began, population will increase until the new advances in production are used up. In the mean time all those extra people will further degrade the natural environment that we depend on for our existence.

If you want to see the other likely consequences, go back and read what resulted from the 60's green revolution.

Note: It has been reported that a number of genetically changed plants caused organ failure when fed to rats.

Extra agricultural production only pushes us closer to the brink. The last thing you want when you are standing at the edge of a cliff is a great leap forward.

As was mentioned above, since the 60's it has been noted that when a country achieves a certain level of prosperity, birth rate falls. This is a modern phenomenon. It didn't happen anywhere in Europe before the last century. Britain's birth rate remained high all through the industrial revolution with well off Brits having as many children as their poorer cousins. Think back to your grandfather and great grandfather's family. How many children did each of your ancestors have as far back as you can trace. The difference, as previously mentioned,  in the 'modern era' is contraception.

Contraception has been available at least from Roman times, but it only became truly effective when it was modernized and put into the hands of women. Both the pill and the effective IUD (as opposed to previous less than adequate models) only became practical from about 1960 onward and they have had a huge effect in countries where they are affordable either because the economic level of the population makes them so or because the government has subsidized them.  In both cases, birth rate has fallen precipitously. Ignoring immigration, which is another story, most European countries have decreasing populations. What a success - and they are fighting against it tooth and nail. That is also another story.

I lived in South Africa for 15 years, much of the time in the homeland of Gazankulu.  Despite an educational level of around grade 2 amongst many of the women, they would come into the clinic for their 3month jab to keep them from getting pregnant.  There is a vast difference between not having a formal education and being stupid.  These women were clever and fully realized the advantages of having less children.  Their men were not so smart.  They would have beaten the women if they knew what was happening.

We must learn to live in our respective countries with a stable and then a reducing population. This , of course will result in a population in which the age distribution curve is heavily skewed toward older people. We have to work out ways to live and live well in such a society. For far too long we have been living in a pyramid scheme in which each generation had to be larger than the previous one. 

This was necessary so that there were enough young people to fill the more menial jobs before they rose up to higher levels.  It was also necessary in order to have enough working people to provide the pensions of the retired. This, quite frankly, is a stupid system.  The pension contributions of the working public should go into buying up the means of production.  Pensions are then paid  from the dividends from these companies and even from selling the shares to presently working people.  The elderly become a boon rather than a drain on the economy as they spend their pensions.  

Our system can't go on.  We must stop importing so-called cheap labor to fill the positions of the children we are not having. In the long term, cheap labor is very expensive.

Note that people are now worried about robots taking over our jobs.  Surly these two phenomenon fit together beautifully.  We have less jobs available and less young people to fill the positions.  The critical factor is taxing fairly the companies who are producing their goods by automation instead of by people.  Too many large corporations now get away with paying little if any tax.  This tax money then goes to the unemployed, whether young or pensioners.  The companies should also face up to reality.  If people have no money they can't buy the goods they produce by automation.  It is in their interests to have money in the pockets of the people.


Pyramid schemes collapse and the mini collapse we are going through at present (2008ff) is nothing compared to what is to come if we keep increasing agricultural production rather than concentrating on reducing population. If we continue this way, we will soon have an answer to the question of who is correct regarding sudden climate change. If the climate change sceptics are wrong, we may very soon achieve the lovelock number.


* Starvation killed an estimated 50m Chinese over the 19th century, 20m Indians in the latter half, 1m Irish between 1845 and 1852, 1/3 of the population of Ethiopia from 1888 and 1892 and 3m in Bengal in 1943. Imagine the effect of the failure of the wheat and rice crop for just one year due to sudden climate change or even from a mega volcano one spring. (link)

** If you double your population or your GDP, you pretty well double your use of water, wood and minerals, double your production of pollution and garbage and double the area of land you cover in buildings.  You continue to eat into unoccupied land, you eliminate all the benefits unoccupied land brings to the human population for free. Below is a table of how long it takes to double all of the above as a function of yearly GDP growth rate. You can calculate it for yourself with a high-school calculator if you put in (for 3% growth rate, for instance) log 2/log1.03.  The '2' is a doubling time, 1.03 is the interest (growth rate).

Annual growth and number of year to double the economy

1%
70 years

2% 35 years
3% 23 years
4% 18 years
5% 14 years

How many countries in the world do you know that can find twice the water, wood, minerals and produce twice the pollution and garbage and still have any quality of life.  The only two I  can think of off hand are Canada and New Zealand.  We don't want to live like this.
Link

Monday, May 8, 2017

Greening the desert

If you could set up a whole bunch of desalination plants, you could pump the water on to a desert somewhere and over time it would green and you would establish a fresh water aquifer.  It wouldn't work.  No one is going to go to that expense for some future nice-to-have ecological result.  No, you need a way of doing it, that in the mean time generates revenue.  Fortunately such a way exists already.

Some time ago I wrote a blog on Sea Water Greenhouses.  You can see it here.

Image result for image sea water greenhouse
Sea water greenhouse can be at any scale.  Note the solar panels powering the pumps and fan.


To recap briefly, you set up a tunnel house with it's long axis parallel to the prevailing wind.  Note that sea water greenhouses will only work if the humidity is low.  You close the upwind end of the tunnel house with a screen made of some wettable material such as excelsior or some types of cardboard such that the wind can blow through this end of the greenhouse.  The downwind end of the Greenhouse has a Solar powered DC fan sucking the air out of the greenhouse and a condenser to condense the moisture out of the air stream.  You dribble your sea water down the screen at the upwind end and collect it in a trough.  You will find it is amazingly cold.  You pipe this water to the condenser at the downwind end in a lagged (insulated) pipe and it will condense out fresh water from the air passing the condenser.  You collect and use this fresh water to irrigate your plants.  You pipe the sea water back to the upwind area and dribble it down the excelsior screen again. Somewhere in this return system is a bleed off that you can adjust so that the water never gets too salty.  This brine is piped back to the sea or into an evaporation pond.

There are many ways to run the agricultural side of such a green house but here I am talking about an open system in which the plants grow in soil on to which you drip the fresh water.  You don't use a closed hydroponic system. The reason is simple.  You want the excess water to flow into the soil and over time create a fresh water, water-table. All by themselves, plants will start to grow around the farm where none grew before.  As more and more of these salt water greenhouses are set up, more and more fresh water will flow into the ground.  You can plant trees and you are on your way to transforming the desert.

The key is in having a farming enterprise that is profitable.

Of course, you may have some other source of water.  There may be, for instance, a salt water aquifer you can tap far from the sea.  No problem and perhaps an extra opportunity.  Not all such aquifers are simply condensed sea water.  They may have valuable minerals in them.  For instance some brines are rich in Lithium, some in Borax.  Whatever the composition of your sub surface salt water, you can let the overflow brine go into lined ponds to evaporate and precipitate out whatever salts are in the water. In the mean time the lighter fresh water going into the soil from your tunnel houses will float over top of the salty aquifer just as occurs in coral atoll islands. The salty aquifer will be sucked down over time as you utilize it and be replaced with fresh water.

In some locations in Australia trees have been cut down to farm the land.  The trees were keeping the salty water table down and without the trees, the area has become a salty swamp.  This would be a perfect place to use such greenhouses and over time replace the salt water with fresh water.  In the mean time, you could have solar ponds to generate electricity.

Incidentally, this will work as a remediation system in areas where salination has ruined the soil.  Often there is salty sub surface water which can be used and replaced by the fresh water your tunnel houses produce.

Thursday, April 20, 2017

Communism and Capitalism

There ain't nothing wrong with either Communism or Capitalism and people that harp on about them are either ignorant or are trying to misdirect your attention from the real problems with both systems.

America uses Communism as their boogy man and communist countries do the same with Capitalism.  Strange in the case of America since her favorite ally is Israel.     Israel is the only country I know of that has had actual Communism.  Their communes are called Kibbutzim (plural of Kibbutz) and were truly communistic organizations.  They provide a good case study of real communism.

Kibbutsim were not the  type of  commune we are more familiar with, with a charismatic religious leader such as with the many communes that self destruct.  With the religious sort of commune, the charismatic leader takes a leaf out of the book of many countries and uses the fear of 'others' to hold his commune together.  Look how America does this with the fear of communism and now her new boogy man, Terrorism.  In the communes we are more familiar with, people get more and more paranoid, often collect weapons and build walls around their commune.  Besides, the charismatic leader, before long, feels that every attractive female in the group should be his 'hand maiden' and this sows discontent. Some of these communes go so far as to commit suicide to bring on the apocalypses.

No, the Israeli Kibutz is run on democratic principles.  In the Kibutz are  a number of different enterprises.  Often they have fish ponds, a dairy, cotton fields, greenhouses for cut flowers and usually a factory producing, say, socks or plastic items.  The leaders of these enterprises are chosen from the group according to their ability and typically hold that position for 3 years.  Then they rotate to another sector in the kibutz, or go to university,or spend some years in the army or are voted to be the lea-son to the general kibutz movement.  One of their members is often chosen to be the head of the Kibutz (also, typically for 3 years).  So what keeps them motivated.

They all get exactly the same allowance to buy things in the Kibutz store, all wear the same clothes, all live in the same standard of accommodation
 and so forth.  Hard to believe, coming from our western societies where money is the measure of all things but they are motivated by their position in the community.  Someone who runs the dairy farm and runs it well is looked up to by all the member of the commune and  this, plus the satisfaction of doing a good job that helps his fellow members makes him always strive to do his job well.

I must mention here that the classic Kibutz system has broken down in Israel but for reasons that have nothing to do with the above.  That might be the subject of a future blog.

Two lessons we should take from the Kibbutz.  One it is democratic and two it recognizes the rule of law.  Everyone has a say at the regular meetings where the policy of the Kibutz is hammered out and no one is above the law. Kibbutzim are fair and equitable and transparent.   They also seem to work best in societies of up to about 250 individuals.  When they get too big, the effect of everyone knowing everyone else tends to weaken.  Incidentally, Kibbutzim are socialistic or if you like communistic inside but capitalistic in their relation with each other, the rest of Israel and the outside world.

So what is wrong with what we call communism.  We associate Lenin, Trotsky and Stalin with communism.  You may not realize it but when Communism began, Americans were flocking to join communist and socialist organizations and unions in America.  Workers were being treated even worse then than today and this was their way of joining together to get a fair deal.  The bosses hated this and went to extremes to stop these movements*.  No way did they want to pay a fair wage for a fair days work.  Then in Russia, Stalin co-opted the movement.

* They used hired goons, then the national guard and in some cases the army.

When the abuses Stalin perpetuated on his own people became known, people left communist organizations almost as fast as they had joined.  His abuses had nothing to do with Communism as such.  He was a ruthless dictator who stifled any spark of Democracy and the rule of law and abused his own people.  To give him credit where a small amount of credit is due, he had to prepare his country to withstand the aggression of Germany and in a new democracy without established mechanisms, he might well,  not have succeeded.

So what is wrong with Capitalism.  Nothing at all.  The problem is not with Capitalism as such but with the destruction of democracy by the leaders who want power and the uneven application of the rule of law. Being a Capitalist or a Communist has nothing to do with democracy or the rule of law.  You can have democracy and the rule of law in both system or no democracy and disdain of the rule of law in both systems.

Look at yourself as a citizen of a so called democracy.  What are you not allowed to do.  You can't steal, obtain financial benefit by false pretenses.  You can't throw your pollution or garbage on your neighbors land or your commons.  You can't bear false witness.  You can't cause the death of other by omission or commission and so forth.  This is all as it should be..... but the law is not applied equally.

Large companies and rich individuals get away with all of these and it takes a huge effort to bring them to justice.  It happens but it is notable in its rarity when a case succeeds against a big corporation or a rich person who is abusing his position.  Corporations and the rich can afford high power lawyers who can find  loop holes in the law to get them out of trouble when an ordinary citizen would be sent to jail for the same crime.

Look at the recent election in America.  America has the finest founding document, (The Constitution), in the world.  The core of this document is that the government is by and for the people.  Chuck out all the rest and leave only this phrase and it would still be the finest founding document in the world.  Look what happened in the DNC (the Democratic National Convention - the body that chooses who their candidate will be in the presidential election).  Debbie Wasserman Shultz in cahoots with Hillary did everything they could to make Hillary the candidate and succeeded despite the fact that Bernie was clearly the peoples choice.  (remember that part about for and by the people).  Then Obama, who is a constitutional lawyer and who swore to uphold the Constitution, came out for Hillary (by and for???).  Then Warren followed suit.  These people only pay lip service to the Constitution, the top law document of the United States.  I doubt if they even understand the concept.

They remind me of some of my religious friends.  They extol the bible but only follow the parts that fit with their world view or even more cynically, the parts that give them some sort of advantage. Actually, it is lucky, to some extent, that they do pick and choose.   Imagine what trouble you would be in if you followed the bible literally and started to stone your neighbor as he cut the lawn on Sunday.  On that line, I find it amazing that the religions right is at the forefront of mining, logging fishing, drilling in parks and in short exploiting nature to the n'th degree with no regard for sustainability while the atheistic left wants to preserve our world in some sort of reasonable shape for their descendants.  Go figure.

Anyway back to the topic.  The problem is not with Communism or Capitalism or any other ism you care to site.  The problem is whether the rule of law is applied equally and fairly and whether or not you have a democracy which is truly by and for the people.  Both can exist in any ism or be absent.  In America Democracy and the rule of law are disappearing at a rapid rate if they ever even actually existed.