Originally posted by Soupornuts
reply to post by eriktheawful
Right, but aren't holocrystalline rocks basically able to act similar to semiconductors ?
They'd have normal skin effect, no ?
In a conductor, skin depth varies as the inverse square root of the conductivity, iirc,
For granite, that would follow Archie's law ?
Forgive me if I'm lost, I just have a lot of questions.
edit on 7-2-2012 by Soupornuts because: to add questions
Semi-conductors are generally made from Silicon and Germanium (most common being silicon). Both of these materials are refined and then doped, and
fused together to form a valence bond. The valence bond makes an area in which the semi-conductor will not conduct electricity, unless baisd with the
correct voltage. A very simple version of a semi-conductor would be a plain old diode, with acts to allow current to pass in one direction only in a
DC circuit, and to act as a "clipper" or "rectifier" in a AC circuit. A good analog of a diode would be like a Check Valve used in plumbing that
allows water to flow only one direction.
In electricity you have Conductors, Insulators and Semi-Conductors. Conductors will allow current flow all the time, Insulators are very, very
resistive to current flow, and semi-conductors will conduct IF they are biased correctly.
Conductors that are normally used are metals, specifically metals that have a lot of what we call "Free Electrons". Basically put: Free Electrons
are electrons who's orbits around a nucleus are easy to break with a force that allows them to move on to other nucleus (IE current flow or electron
flow). Very little force (normally called Electromotive Force) is required to get the electrons to flow. Insulators have very little or no free
electrons and it takes a very, very large force to get their electrons to move.
Metals such as Gold, Silver, Copper, etc, have a lot of free electrons and make very good conductors. Rubber, Plastic, Glass have very little to no
free electrons and make very good insulators (however, if the force is large enough, you can get anything to conduct. But, you'll end up damaging
that material in the process: IE burnt holes, etc.
Granite is made up of the following:
SiO2 — 72.04% (silica)
Al2O3 — 14.42% (alumina)
K2O — 4.12%
Na2O — 3.69%
CaO — 1.82%
FeO — 1.68%
Fe2O3 — 1.22%
MgO — 0.71%
TiO2 — 0.30%
P2O5 — 0.12%
MnO — 0.05%
The silica oxide at the top, can be used as a semi-conductor, but again, in order for it to work correctly, requires refinement. Sitting in a rock,
it's not organized nor refined.
Alumina is actually a insulator when it comes to electricity (but will conduct thermal energy, heat, very well).
There are other conductive materials in granite, such as the iron oxide, but in very, very small amounts, and does not help with conductivity.
So granite itself is more likely to act like a very large resistor, and not a conductor, resisting the flow of current.
You can try this your self. Get a chunk of granite, a lamp, and a long extension cord. Cut the cord open to expose the 3 conductors in it (should be
green, white and black). The green is ground, and white is neutral. Black is the "HOT" wire. cut it and splice it back. Use electrical tape and tape
the bare hot wire on either side of the granite rock. Plug in your cord and then turn on the lamp and see what happens. Nothing pretty much. You'll
be lucky to get a faint glow, but I'd want to see that on video.
DO NOT GRAB THE BARE WIRES OR ROCK WHILE PLUGGED IN! While granite is a lousy conductor with high resistance, YOU on the other hand will make a better
conductor and path to ground, and you could get shocked.
So I'm sorry, if the ancients were so well versed in electricity (and I think the Baghdad Battery says they knew something), then they would know
that granite would be a horrible conductor of electricity, but metal on the other hand is quite good.
Here is a tid-bit though: granite DOES have quartz in it. Quartz is not a very good conductor either, BUT, it does doe some neat things: if you apply
voltage to it, it will "vibrate" at a certain frequency depending upon how it was cut, and it's thickness. The flip side is true: if you vibrate
the quartz, it will generate an AC signal, very week and small, but it will.
However, it's much better to do this with actual quartz and not quartz embeded in other rock.
Hey, I saw an episode of Ancient Aliens where they talked about the pyramids being used for power generation too, but the idea involved gasses, and
not having the granite conducting electricity. Was quite thought provoking. So I'm not trying to debunk who or what built the pyramids, just the idea
of using granite to conduct electricity.
I'm MUCH more impressed with the monolithic structures down in South America, and how they were cut with such precision.