Saturday, May 26, 2012

OBJECT #10: Agate

I can’t remember how I obtained this slice of agate.  My basement contains hundreds of rocks and minerals and it’s easy to lose track of where they all came from.  My husband is the main rock collector, so that makes me “once removed” from parts of the collection, giving me an excuse for not being able to remember where they came from.

    An agate is actually considered to be a type of gem stone, often classified as chalcedony, which is in the quartz family (SiO2).  The name “agate” was given to these rocks by an ancient Greek named Theophrastus, who named them after the river where he found them:  the Achates.

    Many agates probably started out as hollow bubbles in lava.  As the lava cooled, hot mineral-rich water seeped into the bubbles.  As the solution cooled, the minerals precipitated out and formed crystals.  The color of an agate was determined by what kind of minerals were in the solution.  Some of the minerals cooled into very fine-grained rock, with particles so small that the texture of the rock is smooth and glassy.  Sometimes there was enough mineral soup to fill the entire empty cavity, but in some agates the minerals ran out before they reached the center, leaving an empty space.  Often, the edges of the central empty cavity are ringed with large crystal formations. 

    Some agates are found as “geodes,” spherical rocks that must be cracked open to reveal the gems inside.  (Mexico has some really good geode sides.  There are places were thousands of small geodes can be easy collected.)  Some geodes turn out to be “duds” and aren’t much to write home about.  Others will be found to contain crystals that are quite attractive.   One of the largest geodes ever found was in Brazil. It weighed 35 tons and was filled with amethyst crystals (a type of quartz that is often light purple in color).

    One type of agate is not spherical, but occurs in long stripes.  In this case, the mineral-rich silica water filled in long, narrow cracks in the cooling rocks.  They are simply called striped agates, or banded agates.  They have the same beautiful multicolored patterns as the round ones.

    Agates come in lots of colors, but most often in shades of red and brown, gray, or blue.   Agates are used primarily for decorative purposes, such as jewelry or crafts such as book ends.  The only practical use for agates that has ever been documented is burnishing leather (a few places in Asia).  There is a church in Oregon where thin slices of local agates were used as panels for the stained glass windows.  I guess that’s sort of a practical use, but it’s decorative as well, so we could count it in both categories.  You can see from one of my pictures how light will go through these thin slices of rock.  This makes sense when you remember that silica, the main component of agates, has the chemical formula SiO2, which is the same formula for glass (and sand).

    There are lots of places online where you can buy geodes if you want the thrill of cracking open your very own never-before-seen specimen.  If you want a chance to be creative and create your own personal agate design, check out the agate craft idea on my website.  Just click on Free Downloads, then on Earth Science.

Tuesday, May 15, 2012

OBJECT #9: Cow Magnets

    These are cow magnets.  If you’ve never heard of a cow magnet, you are probably scratching your head wondering is this is a joke.  Seriously, these are cow magnets and they are used with cows. Cows are not very discerning grazers.  They will pick up bits of metal along with grass.  Nails, staples and broken pieces of wire fence have been known to lurk under clumps of grass in pastures, and these metal bits end up in cows’ stomachs.  Cows have four stomachs, one of which is the famous rumen, full of bacteria and other microorganisms that digest the grass.  A cow would not be able to live on grass alone without the help of these microorganisms.  This is because animal digestive systems cannot break down the cellulose wall around plant cells.  The nutrients are inside the cell and the wall must be broken down in order to release the nutrients.  Microorganisms produce the right enzymes for breaking apart cellulose.  Ruminate animals have the largest number of microorganisms living in their gut, so they are the ones that can live on nothing but grass and hay.

    The bits of metal in the cow’s stomach can cause damage, of course, but the most damage is done when those bits of metal get all the way into the intestines.  At some point during the last century, a farmer had the brilliant idea of making a cow swallow a large magnet.  The magnet is too large to pass from the stomachs into the intestines, so the magnet becomes a permanent resident in one of the stomachs, often the rumen.  All the bits of metal are attracted to the magnet and are thereby kept from going into the intestines.

    At first they used the smooth type of magnet.  The problem with this type is obvious.  Yes, the metal bits stick to the magnet, but then the magnet can become a mass of prickly bits of metal.  Someone eventually figured out how to design a plastic housing to surround the magnet.  The metal bits are drawn inside the outer diameter of the plastic housing, so hopefully only the smooth plastic will touch the sides of the stomach.

    Young cows are forced to swallow one of these magnets very early in their life.  The magnet then (hopefully) stays inside stomach for the life of the cow.  As far as I know, no attempt is made at recovering the magnet when the cow expires, although I suppose maybe butchers who are cutting up cows for use as meat for our dinner plates, might rescue a magnet if and when they came across one.  I think the magnets are cheap enough that farmers don’t worry too much about recycling them.

    Why do I have cow magnets in my basement?  My husband comes from a dairy farming family.  I think he picked up a few while at the farm years ago, and they have been in my basement collection ever since.  I’ve used them occasionally in my science classes because they are actually fairly strong magnets. 

Wednesday, May 2, 2012

OBJECT #8: Oboe

    This isn’t exactly junk.  But it’s sitting gathering dust in my basement.   In my childhood and teen years this oboe and I spent a lot of time together.  Why, as a fourth grader, did I choose the oboe over all other wind, brass and string instruments?  Because hardly anyone played it, of course.  I had to be different.  I had to tackle the hardest instrument possible just to prove to myself I could do it.  (Little did I know that for the first year I would spend most of my practice time blowing single notes to strengthen my diaphragm, holding the notes for as long as I could, until I could  play a continuous note for the better part of a minute!  A bit tedious for a fourth grader?)

    As a fifth grader I had to begin to make my own oboe reeds.  My teachers said the ones you bought at the music store were junk.  Real oboists made their own reeds.  It was like taking on another instrument.  It was fun at first.  I still have the instructions my dad wrote down for me as we listened and watch my teacher demonstrate reed making.  The paper has translucent oil spots all over it, as the sharpening stone oil would spill out occasionally, soaking the items in the bottom of the fishing tackle box that held all my reed making equipment.  But my dad’s meticulously neat handwriting is still there, the same as the day he wrote it.  and I could make a reed again if I had to, just following those instructions.  My tools included a very sharp specialized carving knife, a sharpening stone, two specialized items called a plaque and an anvil, a cutting block and a razor knife. Amazing, I don’t remember ever cutting myself while making reeds.  (I sliced my fingers with coping saw blades and X-acto wood-carving knives instead.)

    An oboe reed consists of three things:  a stem made of a small metal pipe wrapped in cork, some red nylon string, and a very expensive piece of dried reed imported from Europe.  You had to soak the very dry piece of reed until it was pliable enough to bend in half and be tied around the metal stem.  The wrapping had to be extremely tight.  I would sit straddling a chair with one end of the string tied to the back of the chair so that I could use both hands to pull tightly as I wound the string around the reed.   I would often do up a batch of these “blanks,” then get around to carving them later.

    Carving a reed took me the better part of a hour.  Fussing with it and getting it to sound just right seemed to take forever.  You’d rough it out, then start patiently scraping it thinner and thinner, especially at the tip.  The center of the reed was called the “heart” and had to be not too thin and not too thick. and nicely rounded.  I learned the hard way not to press too hard when thinning the tip.  One crack and the reed was ruined.  Cracked reeds were the bane of my late childhood.  Those dumb things could crack at any time, even right in the middle of a concert.  I’d always have to have some back-up reeds in my case at all times.

    Oboe reeds are a real pain.  You have to store them in a special case so that they don’t get touched or scratched.  Then, when you want to play, you have to soak them in a glass of water for a few minutes.  It’s not like a trumpet or a flute where you can just whip it out and start to play immediately.  You have to sit and wait while the reed soaks for a while.  Dry reeds just don’t work.  So also inside my oboe case I had to keep a little tiny jar of water.  My teacher told me to put some Listerine in the water to keep germs under control.  To this day, the smell of Listerine reminds me of my oboe.  Speaking of odd things in my oboe case, I also had a long goose feather.  My teacher insisted that a feather was the ideal cleaning tool.  A fabric swab pushed through the barrel time and time again could actually increase the diameter of the shaft, altering the pitch or timbre of the instrument.  So I jammed a feather up and down inside each piece of the instrument after I took it apart.  The feather did not absorb the condensed water and the feather came out wet.  Thinking back on it, I wonder that this did not bother me more than it did.  I simply wiped the feather across my pant leg and put it back in the case.

    Because I had chosen an instrument that hardly anyone played, I had opportunities that other kids didn’t.  As a middle school student, I was invited (begged) to play in the high school orchestra.   Since the high school orchestra met first thing in the morning and my school bus couldn’t get me there in time, my poor mother spent two years driving me to the high school five days a week.  In the high school orchestra I was no longer trapped in the realm of simple scores adapted for younger players.  I was introduced to the real world of classical music.  And I found out how many of those classical pieces had oboe solos in them--just about all of them!  I think I spent most of my early teen years with butterflies in my stomach.  The butterflies would get particularly rambunctious in the few weeks preceding a concert in which I had one or more sizable solos. (I even had heart palpitations sometimes.)  A couple of times I talked into playing in a recital where it was just me and a piano to back me up.  After a few of those, I realized that I was not destined for a career in musical performance.  I performed okay, but the stress just wasn’t worth it.  When my oboe teacher told me that it was necessary to begin practicing several hours a day if I wanted to keep improving, I reassessed my relationship with this piece of plastic and metal.

    I made a decision not only to quit playing the oboe, but to leave high school entirely.  I dropped out after my junior year.  Music was just one of the many stresses I was tired of.  I was in the advanced track in all my classes and was putting in at least 6 hours of homework every night, plus weekends.  45 minutes on the bus each way, to and from school...  I thought college couldn’t be worse that was I was doing.  (And I was right, as it turned out.)

    I think my own experiences with school stress were partly what led me to consider homeschooling for my own children.  I had spent the bulk of my teen years feeling stressed out all the time.  Was that really a necessary part of education?  I decided it wasn’t.  I wanted my kids to have a wonderful, relaxed childhood even into their teen years.   I think the teen years are more grand finale of childhood than the beginning of adulthood. As things have turned out, several of my kids have chosen to take a few classes at our public high school, to supplement our homeschooling curriculum.  They did just fine and didn’t get stressed out the way I did.  They never learned or worked “just for a grade.”  They never had to worry about their grade point average.  They were simply interested in learning.

    One of my sons almost went into music.  He is an accomplished guitarist and plays percussion on the side as well.  He composes and records songs in the music studio I built for him in our lower garage.  He debated long and hard about whether to become a professional musician, then decided to keep music as a hobby and go into landscape architecture as a career.  Music is so much a part of him that I doubt his guitar will end up as “junk in a basement,” like my poor oboe has.  For him, music is a de-stresser, not a stresser.  He plays his guitar to relax and unwind.  I like it that way.