Thursday, January 15, 2015

Arkansas Bauxite - the History of Aluminum

Copper has been worked and used by humanity for at least 11,000 years.  Tin has been extensively exploited for at least 5000 years, and iron has been used for nearly as long, but heavily for about 3000.  Aluminum, however, has been in widespread use by humanity for only about 120 years.  Nobody even knew that the metal existed until the mid-1700s, and it wasn't until 1827 that anyone succeeded in separating the pure metal from its ore.  It took another 60 years before, in 1886 and 1887, anyone found a way to separate the metal from its ores effectively enough to allow its commercial use.  But once this was achieved, it rapidly changed the world due to its strength, light weight, and electrical conductivity.  Yep... I did say electrical conductivity.  Along with making the large-scale production of airplanes and the modern science of aviation possible, aluminum was used heavily in early electrical distribution systems, though copper later replaced it.  The rock shown is a piece of Arkansas bauxite, or aluminum ore.  Arkansas produced over 75 millions tons of aluminum ore of this sort between 1898 and 1981 from a region a short distance to the southwest of Little Rock.  The area was, for a brief period, one of the nation's largest suppliers.  An excellent brochure on the history of bauxite production in Arkansas, produced by the Arkansas Geological Survey, can be found at http://www.geology.ar.gov/pdf/pamphlets/Bauxite.pdf

Saturday, January 10, 2015

Onyx Cave, Arkansas


Draperies of flowstone are only one of several types of speleothems, or cave formation, that can be found in Onyx Cave, near Eureka Springs, AR. The term 'onyx' is not a mineral name, but rather a commercial one. It has been used to refer to a number of different rocks or gemstones over history, but most often refers, today, to a dark or black agate or to travertine calcite. The onyx of Onyx Cave is travertine calcite, or limestone, and the formations were formed by slow precipitation of the mineral from groundwater.

Onyx cave is a publically accessible tour cave.  Several other caves that are open for tours are also found in the same region, and this isn't a coincidence.  The southern Ozark Plateau has one of the densest populations of caves and karst formations on the planet.  The region is underpinned by up to 1500 feet of soluble limestone and dolostone, and  is very old.  Most of the sedimentary rocks are 340 million to half a billion years old, and they have been heavily fractured at several points in geologic history.  Great age, soluble rock, fractures, and groundwater means caves - lots of caves.

Wednesday, January 7, 2015

Walking on the Moon


The problem is reputation.  I still have people, now and then, that come into my store, find out that I’m involved in planetary science, and firmly express their opinion that humanity never landed on the moon; that the whole thing was faked.

We did.  Really.  And when I say ‘we did’, I mean ‘We a nation; we a species… landed on the moon.’  Not only is it true that we landed on the moon, we can prove it in lots of ways, not the least of which is by going and looking at the stuff that we left behind while we were there, such as tracks, little moon rover cars, and garbage. (links to images are here: http://www.nasa.gov/mission_pages/apollo/revisited/ )  There are, in fact, dozens and dozens of ways that we can prove that we visited the moon.  There are people that spend their entire lives studying the rocks that we brought back and managing the missions that capture images of the stuff we left behind while continuing to study the topography and geology of that distant, shining orb, and anybody willing to do the hard work can become one of these people.  I've spoken directly with one of the fellows that drove a little buggy around the surface of that barren desert and came back to tell the tale.  A significant number of these people are still alive.  You can meet them and hear them speak, online or in person.  And you and everyone else in the world can see the equipment that we used to achieve the task on display at Johnson Space Center, the National Museum of Air and Space, and in several other publicly accessible repositories.

So why, when there is absolute and compelling evidence that we, as a species, have been to the moon and returned with souvenirs to tell the tale, are there still reasonably rational people who doubt that it ever happened?

The problem is reputation.  If you ask anyone alive at the time of the moon landing, ‘did we land on the moon?’ most of them will tell you ‘yes!’  And they may remember it as one of the most important and compelling moments in their lives.  If you ask the same people a slightly different question, ‘Would the US government have faked a moon mission if they thought it would hurt or intimidate the USSR and help to win the Cold War?’ I think the same group of people would answer with a resounding ‘Oh, heck yah!’ 

This makes it hard to make fun of folks who think we never made the trip.  In 1969, African Americans has been ‘citizens’ for 99 years, but had effectively been allowed to vote for four.  Women had been ‘equal’ citizens, with the right to vote, for 49 years, but congress was 98% male, and it was the most diverse congress in US history to that time.  People still thought tobacco was soothing and healthy for the throat.  We had stopped using the lobotomy as a ‘cure’ for bad behavior only a few years before, and we still daubed mercury on cuts as a disinfectant.  And drug, military, religious, and social ‘educational’ films and posters were… well… just fascinating. 

I don’t blame people who think that we never landed on the moon because I understand that a reasonably humble person, looking back, is forced to reckon with the fact that we have always been pretty good at lying to ourselves, both intentionally and unintentionally.  I’m always a little depressed when someone brings it up in the store, but I understand.  There are few people that would be so na├»ve as to say that we weren't above a little robust propaganda when it came to dealing with the dreaded Soviets.  This human achievement, however, was not a lie.  It wasn't propaganda, and it wasn't the hopeful self delusion of a generation.  It was one of the greatest of human achievements.  And remembering that we did it compels us to do it again, and to reach farther. 

To know that we have taken a first step encourages us to take a second, and compels us with an obligation - to ensure that it is not the last.
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Image: NAC image of the Apollo 14 landing site acquired 25 January 2011. Descent stage of lunar module Antares in center, image width is 500 meters [NASA/GSFC/Arizona State University].