What The Future Sounds Like

Chemical Gnomonclature*

Scotoma is the technical term for the blind spot in our field of vision. Our brains interpolate the missing data so we don't perceive a black spot, but in fact we have two scotomas, caused by the lack of retinal cells where the optic nerve joins the retina (see link).

The Periodic Table is a reticulated array of data. In the mid 1930's, element 43 was still conspicuously lacking. Dmitri Mendeleev, that great Russian seer of visions and father of the Periodic Table, foresaw its existence and called it eka-manganese, meaning "one-after-manganese." Here's what the family of transition metals looked like in the mid 1930's:

Chemists sought eka-manganese unsuccessfully for 75 years after Mendeleev's prediction: their efforts are nicely summarized by van der Krogt. Of the fruitless efforts, those of Noddack et al. came closest, and they proposed the name masurium in 1925. Several Periodic Tables from that era even included Ma beneath manganese.

Unequivocal proof for element 43 appeared in 1937, after an Italian team led by Emilio G. Segrè  isolated it from radioactive samples of next door molybdenum which had been bombarded with deuterium nuclei at Berkeley. They named the new element technetium from the Greek τεχνητος, meaning artificial.
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*Gnomonclature is an homage to James Joyce who invented a literary device called gnomon to accentuate character or story element.  In the words of his character Stephen in A Portrait of the Artist as a Young Man:

Absence is the highest form of presence.

The absence of eka-manganese drove generations of chemists to search for it because it was there--somewhere.

Natrium Facit Saltus

Metallic sodium is hot stuff.  It's sold in chunks or slabs immersed in oil to protect it from air and moisture.  I used to play around with it in the lab. I'd cut up chunks with a spatula (butter knife) and weigh it out for various uses.  It was always fun to toss any excess into a bucket of water and watch it sputter and bluster, forming itself into a smaller and smaller ball as it skittered across the surface, held aloft by the hydrogen gas it was forming. Sometimes it would even catch fire.  Here is a video showing this: link.

The thing about sodium is that it is so ubiquitous.  Universally, not just terrestrially. Unlike plants, we humans need sodium, yet nowhere near as much as we get. The whole "salt" debate is controversial. For leading links, check out the comment section in the following link.

Lesser known about sodium is that it gives us a pretty peach color which we associate with fire. But not the fire of the sun.  The orange blaze of the sun is really white light filtered by our atmosphere and lacks the orange color of sodium. Let me explain.

The sun floods us with a spectrum of visible light.  Here is the solar spectrum sorted according to ROY G. BIV wavelength:

Missing from the solar spectrum are several well known "lines" having alphabetical designations. These Fraunhofer lines were discovered in the 19th century by early German spectroscopists who first analyzed sunlight.  The black bands are "missing" wavelengths caused by the absorption of those colors by different chemical elements present in the outermost regions of the sun. Sodium in the sun causes the pair of lines labeled "D" in the solar spectrum. We don't notice that the lines or specific colors are missing from sunlight because our eyes aren't able to distinguish a missing wavelength, especially when surrounded by others (especially ones close in wavelength).

Here on earth, sodium in flames gives an intense orange glow which is the exact color missing from sunlight. Try sprinkling a little salt on an open flame sometime--you should see an intense light that looks like this:

The sodium spectrum above reminds me of an old-fashioned AM/FM radio dial found in 20th century automobiles and stereo systems. Sheesh I'm getting old fast.
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When I was researching this blog post, I kept running across articles which ascribed the color of campfires and the like to the intense color of sodium. I thought this was odd because plants for the most part do not require sodium, so any sodium present in wood must be adventitious and probably sequestered away.  It turns out that the common orange color seen in burning wood is partially due to residual sodium, but mostly comes from luminescent soot particles, a phenomenon first explained by Michael Faraday (link).

Conversations with Henry

Henry: Back in my day there were still holes and notches in the Periodic Table.
Henry sketched:

Me: But aren't the notches just from how we think about things?

Henry: Meaning?

Me: Meaning that the "notch" in the s- and p-blocks are because hydrogen and helium don't really belong to either block?

Henry: That's bullshit.  They certainly do belong with those other elements.

Me:  OK. So the notches come from discontinuities. Hydrogen and helium are completely s in character--and so are lithium and beryllium.

Henry: So why is helium parked over the p-block?

Me: Exactly! It really shouldn't be there.

Henry: Bullshit.  Helium is a noble gas. Of course it belongs there. Duh.
Henry looks at his cards and frowns.

Henry: I'll take two.
He discards two cards and I give him two more.

Conversations with Henry

Absence is the highest form of presence.

-- James Joyce A Portrait Of The Artist As A Young Man

[Henry and I are sitting at a table in his backyard, about to play a game of cards. Henry picks up a .22 rifle leaning against the table and aims it out at the garden and fires. A puff of soil dust appears near a gopher hole.]

Henry: Damn! Missed! He's been eating my turnips.
Henry picks up his cards and looks at them. I do likewise.

Me: What did you think of the election?

Henry: We can basically do two things: build schools or build prisons.

Me: OK, but do the teachers and guards have to break the bank?

[Long pause]

Me: Henry??  Where'd you go?