<?xml version="1.0" encoding="UTF-8"?>
<!--Xholon Workbook http://www.primordion.com/Xholon/wb/ (C) Ken Webb Tue Apr 10 2012 09:49:47 GMT-0400 (EDT)-->
<XholonWorkbook>
<Notes><![CDATA[
Xholon
------
Title: Electricity generation
Description:
Url: http://en.wikipedia.org/wiki/Electricity_generation
InternalName:
YoutubeId:
Keywords: 1480, electricity
My Notes
--------
If you unexpectedly travelled back in time 500 years, how would you generate electricity to recharge the batteries for a favorite electronic device that you were carrying? I'm particularly interested in the Inca Empire around the year 1480.
The Wikipedia article on electricity generation mentions "seven fundamental methods of directly transforming other forms of energy into electrical energy". The two methods that seem the most promising are::
Electromagnetic induction, such as in an electrical generator
Electrochemistry, such as in an Earth battery
This workbook will look at both of these.
Earth Battery
-------------
An Earth battery consists of two dissimilar metal bars (electrodes) in damp ground, with a wire running between them. The rechargable battery that needs to be recharged would be attached to two endpoints in the middle of the wire. The electrodes should be aligned north south, and should be a meter or more apart. The descriptions I've read suggest using copper and iron, or copper and zinc/iron, or zinc and carbon, as the electrodes.
The metals used in the Inca Empire were gold, silver, copper, bronze, and tin. They didn't use iron or steel. Inca jewelers were quite sophisticated and may have been able to make wires from copper, silver, and gold.
It's unclear from the literature I've read how much current can be generated this way. It may not be enough to charge an electronic device. It could also damage the device, so no one should try this without knowing a lot more.
See also::
http://en.wikipedia.org/wiki/Electromagnetic_induction
http://en.wikipedia.org/wiki/Electrical_generator
http://en.wikipedia.org/wiki/Electrochemistry
http://en.wikipedia.org/wiki/Earth_battery
http://en.wikipedia.org/wiki/Telluric_current
Galvanic series (properties of various metals and other substances)::
http://en.wikipedia.org/wiki/Galvanic_series
http://www.corrosionsource.com/FreeContent/1/Galvanic+Series
It's possible that one electrode could be made of copper, while the other could be made of silver or gold.
]]></Notes>
<script implName="lang:python:inline:"><![CDATA[
print "We should build a small electrical generator."
]]></script>
<script implName="lang:javascript:inline:"><![CDATA[
print("An Earth battery sounds easier to make.\n");
]]></script>
<_-.XholonClass>
<!-- types of domain objects -->
<PhysicalSystem/>
<!-- Earth battery -->
<Circuit/>
<VoltaicCell>
<EarthBattery/>
<LemonBattery/>
<PotatoBattery/>
</VoltaicCell>
<Electrode/>
<Electrolyte>
<WetSoil/>
</Electrolyte>
<Earth/>
<TelluricCurrent/>
<Wire/>
<Load>
<ElectronicDevice/>
</Load>
<!-- methods of electricity generation -->
<ElectricityGenerationMethod/>
<ElectricityGenerationMethods/>
</_-.XholonClass>
<xholonClassDetails>
</xholonClassDetails>
<PhysicalSystem>
<ElectricityGenerationMethods> <!-- 7 fundamental methods -->
<ElectricityGenerationMethod roleName="Static electricity"/>
<ElectricityGenerationMethod roleName="Electromagnetic induction"/>
<ElectricityGenerationMethod roleName="Electrochemistry"/>
<ElectricityGenerationMethod roleName="Photoelectric effect"/>
<ElectricityGenerationMethod roleName="Thermoelectric effect"/>
<ElectricityGenerationMethod roleName="Piezoelectric effect"/>
<ElectricityGenerationMethod roleName="Nuclear transformation"/>
</ElectricityGenerationMethods>
<Circuit>
<ElectronicDevice/> <!-- the device being run or charged from the current -->
<Wire/>
<EarthBattery>
<Electrode roleName="copper electrode"/> <!-- north -->
<Earth>
<WetSoil roleName="wet soil"/>
<TelluricCurrent/>
</Earth>
<Electrode roleName="other electrode"/> <!-- south -->
</EarthBattery>
<Wire/>
</Circuit>
</PhysicalSystem>
<Blockbehavior implName="lang:python:inline:"><![CDATA[
]]></Blockbehavior>
<Blockbehavior implName="lang:javascript:inline:"><![CDATA[
]]></Blockbehavior>
<EarthBatterybehavior implName="lang:webEditionjs:inline:"><![CDATA[
print("\nLet's build an Earth battery.");
]]></EarthBatterybehavior>
<Blockbehavior implName="lang:bsh:inline:"><![CDATA[
]]></Blockbehavior>
<Blockbehavior implName="lang:jruby:inline:"><![CDATA[
]]></Blockbehavior>
<Blockbehavior implName="lang:groovy:inline:"><![CDATA[
]]></Blockbehavior>
<SvgClient><Attribute_String roleName="svgUri"><![CDATA[data:image/svg+xml,
<svg width="100" height="50" xmlns="http://www.w3.org/2000/svg">
<g>
<title>Earth Battery</title>
<rect id="PhysicalSystem/EarthBattery" fill="#98FB98" height="50" width="50" x="25" y="0"/>
</g>
</svg>
]]></Attribute_String><Attribute_String roleName="setup">${MODELNAME_DEFAULT},${SVGURI_DEFAULT}</Attribute_String></SvgClient>
</XholonWorkbook>