Thread by @PnictogenHorses

the most important technological development since the days of the Second World War has undoubtedly been the elaboration of the *semiconductor*. the raw might of electricity—its power to move motors, cause lights to glow, and so forth—was now subject to minute control.

(1/x)

"semiconductor" means only "half-conductor", hence the name is somewhat misleading. while it's true that semiconducting materials tend not to be as electrically conductive as pure metals, partial conduction of electricity is not the distinctive feature of semiconductors.

(2/x)

what distinguishes semiconductors, and makes them useful, is the mode of electrical conduction—the way that the electrons move through the material.

in metallic conduction, electrons move through a continuous "sea" of electron density, shared by all atoms in the metal.

(3/x)

in the ideal case, a valence electron in a mass of (say) copper metal can travel freely from one end to the other, unbound by any particular atomic nucleus.

these electrons are "delocalized", in other words. they're in a common pool, shared throughout the metal's bulk.

(4/x)

this delocalization of electron density in metallic bonding contributes to many familiar physical properties of metals, such as malleability and ductility. the metal's shape, set by its nuclei, can be changed freely without disturbing this pooling of electron density.

(5/x)

semiconductors, by contrast, are *rigid*.

their conductivity arises from the creation of deliberate imperfections in a crystal lattice that would otherwise be complete and non-conducting.

consider the case of silicon. ultrapure crystalline silicon is an *insulator*.

(6/x)

in pure crystalline silicon the atoms are arranged in a rigid lattice similar to that of carbon atoms in a diamond. the valence electrons of silicon are confined to bonding the Si atoms together. there are no *mobile* charge carriers—no conduction of electrical current.

(7/x)

only *imperfection* will allow for electrical conduction through silicon—this fact amuses me, because right-wing mountebanks of the @michaelshermer / @mtaibbi / @elonmusk sort place such an extreme emphasis on perfection and purity, even though none of them is perfect.

(8/x)

introducing an atom with *too many* valence electrons into the silicon crystal lattice—phosphorus, say, which has five valence electrons instead of carbon's four—leaves an excess electron, a "mobile" electron, loose in the crystal lattice, able to conduct electric current.

(9/x)

but if a silicon atom is replaced with an atom deficient in valence electrons—boron, say, which has three electrons in its outer, bonding orbitals—then a "hole" is produced, an empty space that can hold an electron. this, too, furnishes a medium for an electric current.

(10/x)

semiconducting materials with an *excess* of mobile electrons in their crystal lattices are said to be "n-type"; electron-deficient materials with holes in their crystal lattices are called "p-type".

phosphorus (P) is an "n-type" dopant of silicon; it's a bit confusing.

(11/x)

with these unusual materials—crystals containing electrons in excess, and crystals missing electrons that "should" be there—humanity has built many remarkable machines. semiconductors allow for precise control over the flow of electricity, and they can be made very small.

(12/x)

the semiconductor has given such persons as @ID_AA_Carmack, @pmarca, @jack, and @elonmusk a taste of unlimited creative power—as if the microprocessor were somehow the fabled "philosopher's stone" of the alchemists, the ideal transformative substance.

(13/x)

(the Elric brothers really dislike you, Mr. @vicmignogna. I think perhaps we've already informed you? they'd rather not be associated with a sexual offender, however distantly.)

perhaps magic can be done with semiconductors, but semiconductors, themselves, are not magic.

(14/X)

they have physical limitations. they're made of matter; they are subject to failure and breakdown and unreliability. this is true of all materials—it's a truth that the #computer and #programming communities have insufficiently learned. their machines fail...frequently.

(15/x)

@elonmusk wishes to sell @mtaibbi and others the illusion that @Twitter is an eternal machine, a perpetual motion machine in fact—an engine for making infinite money. in reality #Twitter is quite breakable, quite frangible, and it wasn't made all that well to start with.

(16/x)

permit me to guess, if you will, that we're about to learn just how a machine like @Twitter breaks. oh, there have been warning signs. that's one thing common to #capitalism and its leaders, people like @elonmusk: they've figured out a million ways of *avoiding warnings*.

(17/x)

really it's not that much different from a bad boss (@elonmusk, say) claiming that a broken motor is "supposed" to emit smoke. we all know this sort of behavior. "it's meant to shake around and rattle like that".

#ElonMusk knows everything, after all. right?

~Mona Drafter

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