Sunday, February 28, 2010

Get Your Carbs Here!

A single blogpost will just not cut it for carbon, the 6th element. There are so many interesting little sub-topics to cover like diamonds, graphite, buckyballs, and nanotubes. But that wouldn't even begin to touch on compounds, e.g., the hydrocarbons, which give us energy and which also fuel human conflicts past, present and future. And then there's carbon combining with other elements that I haven't reached yet- elements like nitrogen and oxygen: hello, CO2 anyone? Of course that wouldn't get us to carbohydrates or even amino acids, let alone to proteins and things that make up living creatures. I'll probably end up doing several blog posts on carbon, but also keep moving ahead.

Many chemists fall so in love with carbon that they never get past it. Those chemists are called organic chemists. To help understand why carbon is so special, consider a "carbo-centric" version of the periodic table which any Organiker should love:


That chart used to be standard fare at German universities (and let's face it: until the end of WW II, the Germans were organic chemistry). Notice how carbon sits dead center in a row of nine elements, having an equal number of elements to its right and to its left. Here is that first row or period again, pulled out of the chart:

    He     Li    Be     B      C      N     O     F     Ne

Carbon is the first element beyond helium that is found (practically) pure in the elemental state. In general, when commingling, elements tend to gain or lose valence electrons to resemble the nearest noble gas: elements to the left of carbon (e.g., Li+, Be2+) achieve the electronic nobility of helium by doffing one or two electrons respectively; elements to the right (O2-, F-) achieve the nearest noble gas configuration of neon by gaining one or two electrons; elements in the middle (B, C, N) tend to neither completely gain nor to lose electrons, but rather, to share electrons with other elements. These tendencies are a consequence of electronegativity. Carbon also forms so many compounds because of catenation. Catenation is just a fancy latinate word for "linking together"-something that carbon is good at doing, especially with itself.

Returning to the carbo-centric periodic table above, note that there is a similar row or period centered around silicon:

    Ne    Na     Mg    Al     Si      P      S      Cl    Ar

One might ask whether a similarly rich silicon chemistry exists. The short answer is no, because silicon can't self-catenate like carbon can.  Silicone polymers require the insertion of one oxygen atom between silicon "monomers." But some might argue that silicon-based life, created in our own image, has just begun to evolve--it just finds our oxygen-rich environment too hostile. 

Saturday, February 27, 2010

Friday, February 26, 2010

On The Road To Duluth

My dad invented traveling "econo", way before they ever made a word out of it. We use to camp out during these diving trips, except for the last night when we'd stay in a motel to take a shower and get cleaned up before heading back. So there were really few comforts of home. My mother would have never stood for that, nor would he have done that to her. He did take her up there once or twice when we were really little (more on that later), but that stopped after a while (I think she hated it actually). But things were different with us boys-he had things to show us.

Now many of the wrecks we visited were best accessed from private property and my dad maintained contacts with the property owners over the years. Sometimes, (I'm thinking of one very photogenic wreck in particular) we camped right on the grassy shore just yards from the wreck itself (I'm going to do a whole blog post on that one when we get there). But mostly there was a lot of roughing it. I remember spending one night camped at a turnout on Highway 61. A big truck pulled over there too at midnight and idled all night until dawn.

We always set out in the morning from Madison, driving all day, stopping only for a Big Mac for lunch (my dad's favorite road food) but then not again until we hit the other side of Duluth. We always took I-90/94 to Eau Claire and then US 53 to Duluth to catch US 61. We'd always camp just on the other side of Duluth at a small commercial campsite.

Duluth is a very aesthetically pleasing city and well worth a visit. The city is built along a hillside and descends down to the harbor. It has lots of old Victorian homes and many old fashioned elm-lined streets (the perma-cold keeps Dutch elm disease in check and many of the elms are original). I'm sorry that I don't have any photographs of the city, except those in my mind. We were usually in a hurry to get on through and on with the trip. If I were to ever go back, I could see spending a little more time in that fair city.

Wednesday, February 24, 2010

Revisiting Highway 61

That photo was taken along Minnesota's Highway 61 by my late father sometime in the 70's. The concrete wall is kind of unsightly (imagine it's not there) and is a safety eyesore only then recently added. [Added: that stretch of Highway 61 no longer exists and has been replaced by a tunnel].

State Highway MN 61 follows the Lake Superior coastline from Duluth all the way to Canada. Prior to 1991, MN 61 was part of US 61, or as Dylan referred to it, Highway 61 (yes, that Highway 61).  Highway 61 was also called the "Blues Highway" and it stretched from Canada all the way to New Orleans. Before the interstate system, US 61 was a main route north-south, much like US 66 was a main route east-west. In my humble opinion, that particular stretch of MN 61 is one of the most beautiful and scenic drives in the continental US (and I'm including both coastal California and New England!).

Minnesota's Lake Superior coastline is shipwreck rich. Map The reason there are so many wrecks is simply because there were so many ships and also because the lake was a cruel and harsh place to navigate before modern navigational equipment. Duluth was once a leading shipping port city (at one time it had more millionaires per capita than any other America city). The ships came first to carry away furs and pelts from the interior; then they came for timber and grain; then for copper, and then finally, for the iron.

The Iron Range is (or was) a massive geological deposit of iron ore-so much that it fed the entire steel industry "downstream" at the other Great Lakes [added: about a quarter of it came from just one pit]. Great old industrial cities like Detroit, Cleveland and farther inland, Pittsburgh were built from it. Arguably, the only physical reason those cities were ever great (laying aside the great people for a moment) was simply the melding together of Appalachian coal and Minnesota iron to make American steel. The boom years lasted for well over a half century.

My dad started scuba diving up there in the early 1960's. He had an acquaintance who lived up there and who had discovered one or two shipwrecks. Back in those days scuba diving was still relatively uncommon, not at all like it is today. There were no dive shops (in Madison at least). Scuba tanks could only be filled at welding shops or fire stations. Some gas stations had air-compressors that went to high enough pressures but they usually didn't filter and the compressed air tended to be contaminated with pump oil. Diving gear had to be bought by mail order from companies that advertised in the back of magazines like Skin Diver or the likes. Most equipment was still manufactured either in California or Italy (it's probably all made in China now like everything else).

When I was 15 my dad took me on a scuba trip to Lake Superior along Minnesota's North Shore. My brother and I had been around diving since we were little kids, but he waited until we were older and had passed a certification course before taking us up there. He took us separately (there's a 3 year age difference there), mostly for reasons of space and equipment limitations: we always drove up from Madison and had to pack a week's worth of gear, camping equipment, and food.  I recently got around to digitizing some slides he took and so have decided to start yet another blog post series to remember all these things before I get old and forgetful. I'm still looking for some photos I took. At least there'll be pictures this time so don't go away.

Monday, February 22, 2010

Quote Of The Day

Water grows colder and colder and suddenly it's ice. The day grows darker and darker and suddenly it's night. Man ages and ages and suddenly he's dead. Differences in degree lead to differences in kind.
--John Barth The Floating Opera

Saturday, February 20, 2010

Letters Home: "Well, I shot him"

This letter was tucked into a letter sent home by my father. It was from his older brother J who was then deployed to Korea.
February 19, 1952
South Korea

Hi “Short Timer”
Well I am sitting close to the stove and trying to keep warm. We are way down in South K. now but its still sort of cold.
I have been out on an Out Post for about 5 days guarding a Coal mine. They were 9 of us all together and we were about 5 mi from the rest of the Company so you can just about picture what we did. All I did was see that there was a guard list made out and there was plenty of wood cut.
I would have the last man in guard wake me up at 6:00 o’clock so I could go hunting. I never got any thing so far except Crows and Hawks. I have seen Fox and Tracks that I think were Wolf.  Also Deer. There are Wild Boars also. I use a M1 and carbine. I suppose I have shot up about 800 rounds in the last weeks just shooting at different things. I am No.2 on the ration list so I should be on my way home in about two weeks.
I finally made Sgt. at last and I sure hope you can do better than that before you get out of the Army. Well I must close for now and get some sleep.

By for now
Be good
P.S. Don’t write me until you get my new address
I have no clue what the terrain looks like in South Korea but from his description of the types of animals it sounds like southwestern Wisconsin. The area where my dad and his brothers grew up is rich farmland interspersed with densely wooded bluffs known for their spectacular fall colors. Growing up just outside of city limits, they were used to hunting and tracking small game and deer in the bluffs surrounding Richland Center.

Uncle J was the oldest in a family of 8 siblings and in fact, J stands for Jr. because his first name is the same as my grandfather's. A few years ago my brother was visiting him and they were looking over his gun collection which spans a couple three generations. My brother, somewhat of an expert on weaponry, was intrigued by a curious-looking handgun that stood out as a foreign make. Completely unaware of the possible circumstances of his possession, and forgetting that uncle J was a Korean War vet, he asked him about it. According to my brother, their brief conversation went something like this:

Where you get it?

Off a soldier

Was he dead?


How’d you know?

[a brief pause ensued]

Well, I shot him.
My brother told me that at that moment he felt about 2 inches tall, as if he'd bumbled upon an old man's secret.

They say that guys with combat experience rarely talk about it and I have found that to be true.  My backyard neighbor, a marine with two Iraq tours still doesn't talk much about his experience.

It's also not unusual for soldiers to bring back souvenirs from war.  I used to date someone whose father had a Nazi flag that he got in Europe during WW II. But back in '50s it was no doubt easier to bring a gun back than it would be today.

Friday, February 19, 2010

This Is How Families Used To Communicate

Check out the cool stationary my dad was writing on in 1952 during his Basic Training at Fort Knox, KY: This is a letter to my great grandmother, who I do not remember:

The floods he mentions were in the news that year and were bad enough to warrant an Air Force One flyover from President Truman.

Thursday, February 18, 2010

Letters Home: "We Crawled 80 yds On Our Back And Belly With Machine Gun Fire Overhead"

February 19, 1952
Fort Knox, KY

Dear Mom, Dad and all,

I got the letter with the $5.00. I got a pkg. from M_ quite a while ago. It had cookies, home made candy and apple and orange in it. It sure was good. [1]
      I saw the same show you saw quite a while ago The Blue Veil. I guess it was about a woman adopting a kid.  I see Jim and Leslie almost everyday. They are O.K.
I don’t see Lowell any more. He must be through Basic.
      You can tell R_ that when he gets the skirt to lay it aside and I will put it on when I get there. [2]  4 more weeks. We get Fri. Sat. Sun off. Monday morning at 5:00 in the morning we leave for bivouac. That will be for 2 weeks. I might not get to write too often but we will get mail call every night. If we have the right kind of weather it will be fun to camp out.
      We sure put in a rough day today. We didn’t get up too early but had a early dinner and went out on the infiltration course. We crawled 80 yds on our back and belly with machine gun fire over head. About every 20 yds was barbwire about 6 inch off the ground. I sure was glad when that was over. We did it three times. Once with no gun fire, once in the daylight, and again at dark. [3]  The last time they used tracer bullets. Nobody got hit, but it about killed some of the fat guys to get through.
      I got this letter from my landlord in Madison so I might answer it someday. She sure will be surprised. Ha!  To find out I’m in the army and that J_ is married. I guess I will have to sign off for now.

[1] M_ is his older sister.
[2] I added a "fender skirt" tag to this post due to his ongoing obsession with fender skirts.
[2] Night infiltration. You can get a little bit of a feel for how it looks today here.

Monday, February 15, 2010

The War At Home Through The Eyes Of A Child

This August is the 40th anniversary of the bombing at Sterling Hall in Madison. Sterling Hall houses the Physics Department at the University of Wisconsin (I had a year of physics there as part of my undergrad chemistry curriculum). The street shot linked above shows the stately western facade of the building. Around the back of the main building is an annex which houses laboratories, and until 1970, the Army Math Research Center.

Army Math was targeted by the bombers with a truck-load of fuel oil and fertilizer (the same concoction used 25 years later by the Oklahoma City Bombers). The bombers did over $2 M in structural damage, hurt 5, and killed one: Robert Fassnacht, a postdoctoral fellow working through the night on a physics experiment unrelated to the AMRC.

Some news reports said that the blast was heard up to 50 miles away. I was 10 at the time and we lived about 8 miles directly west in Middleton.  I don't remember the blast (it was the middle of the night) but I sure do remember the next day. I vividly remember the TV news reports that night on CBS and even recall that Walter Cronkite had a substitute that evening (Walt must have been vacationing). Oddly, this event was the first time that I fully realized that my insular little childhood world was part of a greater violent and news-hungry world.

The bombers terrorists dubbed themselves the New Year's Gang and were a small circle of students and local misfits. There is good background info at Wiki, and also here. The same bunch also tried to bomb Badger Ordnance using a stolen Cessna plane which took off from the Middleton airport. That bomb failed to explode and was found with fingerprints that ultimately connected back to the Sterling Hall bombers. Of the four Sterling Hall bombers, three were caught but one of them, Leo F. Burt, still remains at large.

Only much later did I appreciate what Fassnacht must have been doing there that night-I did similar things years later as chemistry researcher. Sometimes you just had to pull those all-nighters to get the data. But unlike me, Fassnacht was married with kids, which must have made it even worse. Science graduate students and families are typically poor, and are banking on the breadwinner landing a real paying job one day. It must have been just devastating for his family. I'm cheered to see that part of the community arose to help that young family back then the next day. But part of the community didn't react that way then and now I'm even wondering whether vestiges of that community still linger on.

Fast forward about ten years. In 1979, as a UW undergrad, I attended a premiere screening of The War At Home, an Oscar-nominated documentary which regales the anti-war movement in Madison. The screening was held at the Union Terrace Theater. The film "starred" ring-leader Karleton Armstrong and a number of Madison political luminaries, some of whom had morphed from local student radicals into a local mayoral administration. Some of them were even in attendance, whom I recognized because I was involved with a now defunct newspaper called the Madison Press Connection.

The film itself was mediocre (of course it had a great sound track-just like the 60's did) and it caught some critical flak right off the bat because the filmmakers had overdubbed the thudding sounds of police billy clubs hitting student bodies into some of the historical protest footage (you, know, so we'd feel their pain better).  At the time I was considerably more neutral politically and even more tolerant than I am now. But what struck me then (and what I'll never forget) is the closing or penultimate scene in the movie when the mug shots of the four perps are shown. The filmmakers had the audacity to interject a blacked-out photo frame instead of Burt's mugshot during this sequence as if to say: "we're covering for you man; we're not gonna give you up man." Worse, many in the audience erupted in cheers and applause at this gesture.

I'm not sure that Madison has ever had full closure with the events of almost 40 years ago, nor whether it is even possible. The same student newspaper that instigated the belief that Army Math was somehow complicit in war crimes still foments trouble. The Sterling Hall bombing is like a festering scab on Madison's history. Not until 2007 was there even a plaque or memorial commemorating the event, though the physical scars have long been evident (I found them as a student and would often contemplate them as I walked between buildings).

I await the events of this coming summer and whether somebody will step forward and claim more responsibility for the insanity of 40 years ago.

Friday, February 12, 2010

I Must Be Bored Today

The fifth element, boron, is essential for healthy plants. I once wrote a research proposal focused on that topic. Challenging the notion that boron's role in plants is structural in nature, I proposed instead that boron plays a dynamic role in plant tissue (cellulose) growth instead. The proposal went nowhere, maybe because I was wrong, but also perhaps because I was way out of my element. I'll never know the difference.

Whether we humans require boron is still in question: rats apparently do-though only in miniscule amounts. But boron is absolutely crucial for our silicon-based life support systems, in particular, for our computer chip-driven way of life. Boron's primary use however is boring and mundane: the bulk of it is used in borosilicate (pyrex) glass, commonly used in chemistry labs and in cookware; pretty much the rest of it is used in laundry detergents.

Now the word boron ends in "on" just like carbon, but this wasn't always so. Boron used to go by names like "bore" and "boracium" among others. The name "boron" didn't stick (in the English-speaking world at least) until early workers recognized its profound chemical similarity to carbon (btw, I found the ultimate authority on chemical name origins, so unless I think of something original to add, I'm just going to link to van der Krogt from now on. Notice that one can scroll up and down by atomic number or alphabetically. It's a totally cool website IMO *jealous*. And it figures that the guy is Dutch too).

Boron sits atop an imaginary line running diagonally down across the periodic chart which divides the metals from the non-metals:

Boron is one of the so-called metalloids, having chemical properties intermediate between metallic and non-metallic, just as the name suggests. What makes some elements metals and other non-metals is pretty well explained by band theory, but a simplistic view is to invoke electronegativity. Electronegativity is like a measure of electron selfishness: some elements cling so selfishly to their own electrons that they're unwilling to share them, not even with their identical neighbors-no conductance! So the diagonal line also demarcates a certain threshold electronegativity, the non-metals being more electronegative, epitomized by fluorine in the upper right (not shown).

Boron's chemistry is dominated by its electron deficiency, a consequence of its possessing fewer valence electrons than it has available electron valence orbitals.  Like carbon, boron builds borocentric molecules, typically with up to 4 other atoms surrounding it. Those four neighbors require that boron contribute four electrons to the magic octet, but boron only has three valence electrons to share (neutral boron actually has five electrons to match the +5 charge of its nucleus, but two of the five electrons are permanently locked away in a helium-like configuration: the filled so-called K-shell in the Kos reference). So when forming tetravalent compounds, boron always comes up one electron short and has to borrow one [LOL-boron builds more house than it can afford!].

Boron is used in the semi-conductor industry to introduce electronic "holes" in the atomic structure of chip material like silicon. When a boron atom assumes a position in a silicon structure normally occupied by a silicon atom, there is a bond missing one electron (or in other words, a hole). These holes facilitate the movement of positive charges or "holes" through materials. Other atoms can be doped into chips to do the opposite, i.e., introduce negative charges (i.e., electrons) and when used in conjunction, truly miraculous things happen which actually allow you to read what you're reading here.

This concludes another boring lesson in the chemical elements.

Wednesday, February 10, 2010

Letters Home: "So They Got R's Number"

original photo here
February 11, 1952 
Fort Knox, KY
Dear Mom, Dad and all,
I just got in from the tank range and thought I would answer your letter. I was going to call you last night about 9:00 but they said it would take an hour and a half to get it through so I didn’t bother to call. We got up at 4:30 this morning and got back at 3:30 this afternoon.
We go on a night problem from 6:00 till 10:00 tonight so it will be a long day. It isn’t so bad because the weather is dry and warm. It’s a compass reading problem tonight. I suppose a lot of us will get lost. This is our set ups for the week: Monday: shoot 30 cal. machine gun from inside the tank. Tracer bullets. Tuesday: same thing. Wed: 75 m.m. gun from inside tank. Also 50 cal. machine gun with tracer. Thur: same as Wed. Fri 75 m.m. and shoot 50 cal. at balloons.[1]
I got K.P. Wed. so I won’t get any shooting that day. I think its my last time for K.P. Has Billy S. wrote yet as to where he is stationed?  A new bunch is moving in here the 13th and maybe he will be one of them.
So they got R_’s number. [2]  I hope he don’t get into combat, though the training don’t hurt anyone. I got 5 weeks after this one so be looking for me in April. Did R_ ever get my fender skirt taken off and painted? If he hasn’t tell him to do it right away.
Has Dad ever said anything about coming down and getting me?  I know my car would never make it. Tires are bad and I think it needs a new master cylinder.  Have R_ ask what it would cost me for a new master cylinder. I think about $12.00.
Sure has been nice weather here lately. I hope it's that way when we camp out for two weeks. Has R_ got a car yet?
We saw a big Jet Bomber go over today. It sure was up in the air. 2 big trails of vapor was left in the air for about 5 min.[3]
P.S. Send $5.00.  I spent all my money in Nashville.
[1] That .50 cal machine gun was no doubt an infamous Browning M2 (nicknamed "Ma Deuce"). Browning M2's have been in continuous production since the end of WW I.  If you've never seen a .50 caliber round, you should: they're about 5 1/2 wicked inches long.  My grandfather collected ammunition and arranged them according to caliber on a wall-mounted collection. Growing up, we never asked where he got them, but I think I figured it out. He worked at Badger Ordnance during WW II and I suppose that he managed to slip a few things out in his lunchbox, much like that GM plant worker who built himself a Cadillac from pilfered pieces (OT, but that Johnny Cash song is called One Piece at a Time and you can hear it here.  LOL, I just bought that song from iTunes in memory of my dad and grandad). Coincidentally, Johnny Cash was serving in Germany around the same time as my father, though in the Air Force, and he was stationed further south at Landsberg.

[2] R was his younger brother, who just turned 18 and received a draft number from the Selective Service.  At first I thought that my dad might have deployed to Germany and not to Korea because his older brother was already in Korea. Not true. Same family members may be deployed to the same combat zone, however, in the event of the death of one family member, the other(s) is/are given the option of voluntary transfer out.  I believe these rules date back to the Civil War and for good reason: Link.

[3] That jet bomber was probably not a B-52 which was only first tested in April of that year (1952), unless it was an early prototype. B-52's had four jet engines and probably would have left a characteristic vapor trail, although it's possible that the four trails would have been unresolved to the naked eye and would have looked like two. The jet he saw was probably a B-47.

Thursday, February 4, 2010

Über eine neue Art von Strahlung

In the fields of observation chance favors only the prepared mind.
—Louis Pasteur

Wilhelm Roentgen (Röntgen for the purists & pronounced sort of like runt-ghen, i.e., with a hard "g") rocked the scientific world when he published Über eine neue Art von Strahlung ("On a new Type of Radiation"). The classic 1896 paper described experiments he had conducted the preceding fall. Just five years later in 1901, Roentgen received the very first Nobel Prize in Physics. The citation recited:
"in recognition of the extraordinary services he has rendered by the discovery of the remarkable rays subsequently named after him." 
Roentgen didn't want "his" rays to be named after him, and so (in the English-speaking world at least) they are called by the term he coined: X-rays, wherein the "X" stood for "unknown". An account of Roentgen's serendipitous discovery of X-rays is well documented in the Wiki bio linked above. I have a copy of that first paper (in German) published as Chapter 11 in a remarkable book called The German Scientific Heritage by Reginald Phelps & Jack Stein (Copyright 1962 by Holt, Rinehart and Winston, New York). Roentgen wrote in that classic "tall-by-the-brook-standing-tree" syntactical style that seems so uniquely German. Yet Roentgen was an impeccable experimentalist and had already discovered many of the interesting properties of X-rays and set them forth in that first publication. Most astonishing, and perhaps convincing, was his inclusion of the first ever Röntgenbild: an X-ray photograph of his wife's hand, complete with ring:
Hält man die Hand zwischen den Entladungsapparat und den Schirm, so sieht man die dunklen Schatten der Handknochen in dem nur wenig dunkleren Schattenbild der Hand.

Holding the hand between the discharge apparatus and the screen, one sees the darker shadow of the hand bones within the lighter shadow of the hand.

I bring all this up for two reasons: First: heavier atoms in molecules and hence materials are easier to see with X-rays than are lighter ones. Bones are mostly made of calcium, phosphorus and oxygen: the former two elements #20 and #15, are twice as heavy as the "heavy" elements that make up soft tissue, viz., carbon (6), nitrogen (7) and oxygen (8). Hydrogen (1) is the hardest atom of all to see with X-rays. This is also why MRI is such a great complimentary technique to X-rays: it mainly locates (visualizes) hydrogen in water and hydrogen attached to carbon in soft tissues; bones are mostly invisible.  Chemists recognize the same complimentarity between X-ray crystallography and NMR spectroscopy.  Metals like gold (79) stand out even more sharply by X-ray.  Roentgen realized all of this in his now classic paper in which he tested the transparency of various materials.

Another reason to bring this all up is that screening methods at airports have been in the news lately. X-rays are used to screen luggage and people for bombs and contraband. A good primer on their use can be found here.  I'm still looking for a good reference on the techniques used for full body scans, especially since the apparent threat of bosom bombers would appear to challenge the current systems and methods in place. Plastic explosives like PETN can be distinguished from silicone breast implants, but apparently not without effort.

Meanwhile, Frau Roentgen is ready for her close-up now:

Wednesday, February 3, 2010

Status Quo vs. Change

"...two important aspects of inorganic chemistry (in fact, of chemistry in general) are structure and reactivity.  Someone has said that all of physical science consists of this duality.  In physics we could speak of statics and dynamics, and by analogy in everyday life, the status quo and change."
James E. Huheey Inorganic Chemistry: Principles of Structure and Reactivity 2nd Ed

Monday, February 1, 2010

More Elemental Musings

The single most important piece of scientific literature is, in my opinion, the periodic table.  Those who understand what it means, and what it actually implies, have mastered more science than most professors ever will.  This may sound like an exaggeration, but come with me and I think that I can prove it to you.
         Translator, writing for The Daily Kos

The Dailykos!!  Whoever "Translator" is (and he reminds me of Derek Lowe), he or she put together a wonderful historical synopsis of the periodic table. I highly recommend reading at least the historical section to get a flavor for what went into the development of the periodic table. 

I would add just one thing to Translator's fine discourse, and that is that the modern appearance of the periodic table might lead one to think that there are gaps between elements:

For example, look at the huge gap between H and He, which essentially spans the whole table.  Look in particular at the gap on moving from 4 to 5, ie., beryllium (Be) to boron (B). Why aren't there elements filling those gaps?  The answer (besides the "cute" one that there are no whole numbers between 1 and 2 nor between 4 and 5) is that those gaps are a consequence of the two dimensional presentation of the table which has become standard. While the table doesn't map anything physical in the sense of a photograph of unseen things, it might be useful to think of the gaps in the periodic table in the same way that certain flat maps depict a spherical earth:

In essence, what the periodic table represents cannot be perfectly rendered in two dimensions!
There have been numerous alternative presentations of the periodic table: spirals, pyramids, spheres, etc, none of which ever caught on as the iconic image above did. Several of the alternatives are presented here.