Wednesday, February 29, 2012

Just A Thought...

cuban bob wrote: Our local NPR station had a big story on Monday about how this is killing the funding for highway maintenance.

This reminded me of Ken Burns' "Prohibition" when he taught how a potential loss in federal tax on alcohol was a major deterrent for enacting Prohibition--the Feds wondered how they could recoup losses if such a national prohibition law were to pass. But the 16th Amendment (Federal Income Tax) nicely solved that in 1913 and paved the way for the subsequent Volstead Act.

Beware any national energy tax to offset declining fuel tax revenues--it could be a prelude to a stricter prohibition on hydrocarbons.
crossposted at Althouse

Tuesday, February 28, 2012

"Rutherford was an artist. All his experiments had style."

Ernest Rutherford (1871-1937)
Ernest Rutherford reminds me of Michael Faraday. Born in humble circumstances in faraway New Zealand, he travelled to the mother country to study physics. Like Faraday, equal opportunity earned him a place with the best of his day and this meant the Cavendish Laboratory at the University of Cambridge. Rutherford must have witnessed J.J. Thomson's discovery of the electron there in 1897 but there's no record of him taking part in that work. It didn't matter--he had enough in him for two careers in science and a Nobel Prize of his own. And one of Rutherford's great achievements was the accidental undoing of his mentor's plum-pudding model of the atom.

Rutherford's first independent work was the unravelling of radioactivity along with Fredrick Soddy.  More on this later. But first, I want to close a loop I opened a few posts ago by hinting that I had found an inconsistency. I was referring to Richard Rhodes' account of Rutherford receiving the 1908 Nobel Prize in Chemistry:
An eyewitness to the ceremonies said Rutherford looked ridiculously young--he was thirty-seven--and made the speech of the evening. He announced his recent confirmation, only briefly reported the month before, that the alpha particle was in fact helium. The confirming experiment was typically elegant. Rutherford had a glassblower make him a tube with extremely thin walls. He evacuated the glass tube and filled it with radon gas, a fertile source  of alpha particles. The tube was gas tight, but its thin walls allowed alpha particles to escape. Rutherford surrounded the radon tube with another gas tube, pumped out the air between the two tubes and sealed off the space. 'After some days,' he told his Stockholm audience triumphantly, 'a bright spectrum of helium was observed in the outer vessel.' Rutherford's experiments still stun with their simplicity. 'In this Rutherford was an artist,' says a former student. 'All his experiments had style.' 
~Richard Rhodes in "The Making Of The Atomic Bomb"
Rhodes' book is a favorite of mine and I've read it a couple times. But Rhodes makes no mention of Soddy and Ramsey's proof five years earlier that the alpha particle was helium. According to Wikipedia:
In 1903, with Sir William Ramsay at University College London, Soddy verified that the decay of radium produced alpha particles composed of positively charged nuclei of helium. In the experiment a sample of radium was enclosed in a thin walled glass envelope sited within an evacuated glass bulb. Alpha particles could pass through the thin glass wall but were contained within the surrounding glass envelope. After leaving the experiment running for a long period of time a spectral analysis of the contents of the former evacuated space revealed the presence of helium. This element had recently been discovered in the solar spectrum by Bunsen and Kirchoff.* link
This account essentially parallels the elegant (but later) experiment announced in 1908 by Rutherford and described by Rhodes with the exception of radium instead of radon as the source of alpha particles. However, my review of the 1903 Ramsey & Soddy paper cited by the Wiki actually describes a much different and less elegant experiment. link
*Also, Bunsen and Kirchoff didn't find helium in the solar spectrum--Lockyer did: link

Monday, February 27, 2012

Deep Thoughts By Oppie

It is a profound and necessary truth that the deep things in science are not found because they are useful; they are found because it was possible to find them.
~J. Robert Oppenheimer

Strontium Builds Strong Bones

Naturally occurring rubidium is only weakly radioactive and unregulated, but manmade strontium-90 is practically a worst case scenario. Strontium-90 first acquired its bad reputation back in the 1950's when it, along with certain caesium and iodine isotopes, were identified in the fallout from nuclear weapons testing. Strontium-90 is also a decay product from nuclear reactors. The worst accidents involving strontium-90 both occurred in the former Soviet Union: Chernobyl in 1986 and the Kyshtym nuclear disaster in 1957. link

Strontium-90 decays relatively quickly (it's a beta-emitter) and is taken up in bones. Strontium "rhymes" with calcium and very much resembles it. Strontium is bone-seeking and can supplant and replace natural calcium. Calcium is the backbone of life and modern civilization: think skeletons & concrete. Ca2+ and Sr2+ are both small & hard and can interchange within living structure as oxides and polyoxoanions, e.g. phosphates.

But regular strontium, which is not essential to life, may partially redeem itself. Naturally occurring strontium is not radioactive and strontium therapy shows promise for the treatment of osteoporosis, though its use is controversial. link

Lastly, if the name strontium sounds weird it's because it was named after a Scottish town Strontian (Srón an t-Sithein) where it was first found. Van der Krogt tells the story of its naming here.

Sunday, February 26, 2012

Doing the aftermath of Becquerel's discovery

[continuation in part from here]

Becquerel's discovery of uranium's radioactivity led to several immediate questions:

(1) Were other elements besides uranium radioactive?
(2) What is radioactivity? Was it it like X-rays?
(3) How to square radioactivity with the Law Of Conservation of Energy.

In the mid 1890's the Periodic Table looked like this:

Note that the noble gases (which had just been discovered--were absent). Also, nickel and cobalt were incorrectly ordered under group VIII as I mentioned here.

Marie Curie found that thorium (an element known since 1828) was radioactive in 1898.  There was a priority dispute with a German chemist, Gerhard Carl Schmidt which I'm still reading about. Thorium's importance briefly eclipsed uranium's, because the latter was in short supply until more sources could be found. Curie, along with her husband Pierre, began extracting uranium from samples of impure Czech pitchblende. They discovered that the purer they got the uranium, the stronger the radioactivity was in the concentrated waste left behind. This told them that something else was in there. They discovered polonium in July and radium in December of 1898, adding two new elements to the chart shown above.  In this way, radioactivity became a tool for discovering new elements.

Thursday, February 23, 2012

"Radiation...You Hear The Most Outrageous Lies About It"

A favorite line from a favorite movie--Repo Man:

So in delving into the early history of radiation, I think I'm fact-checking myself into outing a falsification.

More later.

meanwhile, added:
Early radiotherapy

Wednesday, February 22, 2012

The Restless Conscience

I found this movie on Netflix and watched it last weekend.  I wanted to see and hear Freya von Moltke, whom I wrote about here. She appears briefly in the linked trailer at the 1 min 14 sec mark. She is interviewed throughout the movie which tells the story of her husband, Helmuth James von Moltke, whom I wrote about here. The movie isn't about him per se but does an excellent job of fitting him into the larger picture of German anti-War resistance at the time.

If you're into that sort of history, give the movie a watch.  The Restless Conscience (1992)

Monday, February 20, 2012

Decay Matters

Turning and turning in the widening gyre
The falcon cannot hear the falconer;
Things fall apart; the centre cannot hold;
Mere anarchy is loosed upon the world,
The blood-dimmed tide is loosed, and everywhere
The ceremony of innocence is drowned;
The best lack all conviction, while the worst
Are full of passionate intensity.

~William Butler Yeats THE SECOND COMING (1919)
Radioactivity, even more than X-rays, shook up physics at the end of the 19th century. Men and women of reason gradually realized that atoms do break down--that atoms were not indivisible as the name implied but that they could decompose and decay into other kinds of atoms. And when they do break down radiation and lots of mc2 follows.

The man-made sun on earth...

...was first preceded by a moment of darkness. Nuclear weapons were contrived invention, but the phenomena behind them are quite natural. The Sun is our main source of energy--directly or indirectly--and at first its light was thought necessary for radioactivity.

Henri Becquerel (1852-1908)

Henri Becquerel was fascinated by phosphorescent materials--materials which glowed in the dark after exposure to sunlight--including uranium salts. In 1896, he knew of Roentgen's discovery the previous year--the discovery of X-rays--and he wondered if phosphorescent uranium would give off penetrating rays after exposure to light.* Here he describes his eureka moment:
One wraps a Lumière photographic plate with a [Ag] bromide emulsion in two sheets of very thick black paper, such that the plate does not become clouded upon being exposed to the sun for a day. One places on the sheet of paper, on the outside, a slab of the phosphorescent substance, and one exposes the whole to the sun for several hours. When one then develops the photographic plate, one recognizes that the silhouette of the phosphorescent substance appears in black on the negative. If one places between the phosphorescent substance and the paper a piece of money or a metal screen pierced with a cut-out design, one sees the image of these objects appear on the negative...
The shadow of a small copper cross is visible
One must conclude from these experiments that the phosphorescent substance in question emits rays which pass through the opaque paper and reduce silver salts.
But further experiments led him to doubt the necessity of sunlight and to abandon this hypothesis. Later, he reported:
I will insist particularly upon the following fact, which seems to me quite important and beyond the phenomena which one could expect to observe: The same crystalline crusts [of potassium uranyl sulfate], arranged the same way with respect to the photographic plates, in the same conditions and through the same screens, but sheltered from the excitation of incident rays and kept in darkness, still produce the same photographic images.  March 2, 1896
Becquerel's students, Pierre and Marie Curie, went on to discover two new elements, radium and polonium. Marie Curie coined the term "radioactivity" to describe the elements' natural property of begetting penetrating rays.

[story continues]
*Becquerel may have been aware of Niepce de Saint-Victor's near discovery of the same phenomenon a generation earlier. link

Friday, February 17, 2012

The Red Line Of Rubidium

The name rubidium derives from "deep red" in Latin. Robert Bunsen (yes, that Bunsen) named the element that after he and physicist Gustav Kirchoff discovered it burned reddish-purple in a flame. They also found caesium which lies below (rhymes with) rubidium and which burns bright blue. Burning elements is still important in fireworks and also in modern analytical chemistry techniques such as ICP-MS. Also, a fair number of elements are named after colors: chlorine, rubidium, caesium, chromium, rhodium, indium, iridium, iodine, etc.

The depiction above implies how weakly rubidum holds its outermost electron and why it so readily gives it up to become Rb+. Most anything can pluck it off. Here's a spectacular video of rubidium hitting water:

Naturally occurring rubidium has two isotopes: the stable 85Rb (72.2%) and the radioactive 87Rb (27.8%).  87Rb is considered only "slightly" radioactive--despite its abundance (it is naturally present in seawater)--because of its extremely long half-life of 1010 years.  Remember that something has to actually decay in order for it to emit radiation.

Radioactivity is not something which has occurred naturally in the previous 36 elements except in very trace amounts (though artificial isotopes of lighter elements of course exist). Radiochemistry is a fascinating topic unto itself and becomes increasingly important for heavier elements which pretty much means from here on out.

I thought this was profoundly cool:

In quantum mechanics one replaces the word 'orbit' with orbital, a word introduced by R.S. Mulliken who defined it in a simple way by saying that an orbital is as much like an orbit as quantum mechanics permits.
You see, Bohr's planetary model of an electron orbiting the nucleus (the iconic "atomic" symbol) was undone by Heisenberg. There can be no precisely defined position and energy for an electron as there is for a planet. It's a blur. So you can't really say that the electron orbits the nucleus even though you want to think that it does.  That's what Mulliken was trying to convey.

How the past gets Bury'd

I love stories like this one about the man who first noticed and explained what's behind my Rime of the Ancient Elements: alternative proposal was put forth in 1921 by Charles Rugeley Bury (1890-1968), who was a lecturer at the University College of Wales at Aberystwyth. The scheme that he described succinctly in a mere seven pages is essentially the scheme to be found in modern introductory textbooks of chemistry and physics. He deduced from the chemical evidence that the electrons are arranged in successive layers containing 2, 8, 18, and 32 electrons. He gave a clear discussion of the electronic arrangements in the actinides and lanthanides, and even made some predictions (inevitably but not quite correct) for the transuranic elements.
Bury's scheme was reproduced in The Electronic Theory of Valency by Nevil Vincent Sidgwick (1873-1952); this was an important book that first appeared in 1927 and which interpreted the chemical behavior of the elements in terms of their electronic configurations. Sidgwick acknowledged the important contribution of Bury, but almost all subsequent accounts have failed to do so and Bury's name is now almost entirely forgotten.
~Keith J. Laidler, The World Of Physical Chemistry, Oxford University Press: New York, 1993
I can't even find a photo of Bury on the Internet. :(

The Rime of the Ancient Elements*

The discovery of krypton and the other noble gases ushered in a fuller understanding the elements, but it was still some time before the noble gases were depicted as shoring up the whole right-hand side of matter:

click to enlarge
The noble gases at the right-hand end appear to make the table rhyme like verse. The elements arranged in successive rows are like verses of length 2, 8, 18 and 32 elements (the gaps make this hard to see at first).
The natural rhyme of the Periodic Table is written in a 2n2 meter, where n = 1, 2, 3, 4,.. . The atomic numbers of the inert gases show this remarkable regularity:
...2 elements...He[2]
...8 elements...Ne[10]
...8 elements...Ar [18]
...18 elements...Kr[36]
...18 elements...Xe{54]
...32 elements...Rn[86]

The ellipses show the number of elements between rhyming noble gas elements, 2, 8, 18, 32, corresponding to the natural meter, 2n2, with n = 1, 2, 3, 4...

The Periodic Table is much more than rhyming noble gases; each element rhymes with the one above and the one below.  The whole damn thing rhymes.
*Rhyme (rime) and rhythm were once distinctly different notions. The old word rime is a Germanic term originally meaning "series, sequence" as in the sequential ordering of the elements. link

More about the man who first noticed this here: Link

Tuesday, February 14, 2012

Krypton was hiding in plain sight


Perfection can be boring, and so it is with the chemistries of the noble gases. Once argon was discovered 1894, the others were diligently sought and found hiding in liquid air in 1898. First came krypton--its name meaning hidden one--the other two, neon and xenon, were found a few weeks latter. Lord Rayleigh and William Ramsay won the 1904 Nobel Prizes in Physics and Chemistry for their discoveries.
Helium, the first noble gas, was first found in the solar spectrum, not in thin air.

My Funny Valentine

Monday, February 13, 2012

Bromine puts the Purple in Tyrian Purple

Althouse commenter Palladian wrote an interesting comment a while back about Tyrian purple dye:
The ancient purple, Tyrian purple, is more akin to the color of a fresh Welch's grape juice stain on a white cotton shirt, only much more intense. Tyrian purple is made from the fresh mucous secretion of a big sea snail that is variously known as Murex brandaris and Haustellum brandaris. It requires harvesting and killing 10,000 of these gastropods to produce one gram of the dye, hence the astronomical price and rarity of the color. Link.
Palladian didn't mention bromine in his comment but I remembered his post after I started thinking about organobromine compounds.* He didn't give a pretty picture either, so here it is:

So what?  Well, it's bromine that gives it its striking color. Why do I say that?  Take away the two bromines and replace them with hydrogens and you get a dye called indigo:

I am interested in this stuff because I'm trying to understand and explain how organic dyes are used in DNA sequencing and also in OLED devices (futuristic electronic devices).  Subtle changes like changing substituents like bromine (or more commonly chlorine and fluorine) are important to those technologies.
*Bromine is rare in natural compounds and, unlike chloride and iodide, bromide is not an essential element for humans. Due to its high water solubility, the world's bromide is mostly trapped in the oceans, where it cannot easily escape without help. Significant amounts of bromide are also trapped in fresh water brines and brackish waters, which is why Dow Chemical is in Michigan. Link

Saturday, February 11, 2012

Live Fast, Die Old: "Lemmy"

Lemmy (2010) is documentary film about Ian Kilmister, better known to his adoring fans as Lemmy, the founder of Motörhead.*  The film traces his entire career arc, starting back in the British Midlands in the early 1960s to the present day.

Asked about his earliest musical influences, Lemmy mentions Little Richard, Elvis, and The Beatles and he recalls seeing the latter at The Cavern Club in Liverpool before they had cut a record. He challenges a commonly held notion:
Everybody thinks the Stones were the hard man and the Beatles were the sissies and it's really opposite. The Beatles were from Liverpool and the Stones were from the London suburbs--you know, going to art school and shit and so it wasn't that way at all. And The Beatles--I always thought were the best band in the world you know?
There were three phases of Lemmy's career--first came a pop group called "The Rockin' Vickers" which lasted until about 1967. I'm not sure what he did after that except a lot of drugs. Then came Hawkwind, a pioneering psychedelic band. Lemmy was fired from that band in 1975-- a casualty of (in Lemmy's words) "a type of 70's drug snobbery." His band mates preferred "organic" drugs like pot and mushrooms, while he preferred "synthetics" viz., amphetamines.

Motörhead is slang for "speed freak." I never really got into them (though I did see them in Zurich in the early 90's). I always considered them derivative of other metal bands. I was a bit disturbed by all the fawning accolades by American metal musicians for his having "invented" heavy metal. That's not the way I remembered it.  That is, until Ozzy Osbourne weighed in:
If they'd said to me-uh-who would you say was the original metal band? ....It was a toss between Lemmy and Black Sabbath..but I would say Lemmy and Motörhead.
There is plenty of humor in this film. We see his $900/mo LA apartment (man cave) brimming with "stuff." He collects WW I and WW II memorabilia, including a roomful of Nazi "stuff."  We also glimpse a bit of the personal too. Asked "What's your most cherished possession in here?"  Lemmy answers (after a swig from his Jack and Coke): "My son."  The camera zooms out to include his son, Paul Inder.  "I mean he's the only one I've got.  I mean I have another one but I've never seen him."  Paul tells the whole story--about his mother, his own curiosity about not having a father, and their eventual reunion. We learn too that Lemmy's own dad abandoned the family way back when. This was the only time I could sense resentment in the man.

Man, I just hope somebody is following Dick Dale around with a camera.

Here's a working link to Lemmy's signature song, Ace Of Spades.

BTW, this isn't from the movie but here's Lemmy talking about drugs:

*Blue Öyster Cult claims to have been the first band to use an umlaut in their band name because of the Wagnerian aspect of metal bands. link

Wednesday, February 8, 2012

Little Things Matter Too

I took a Hunter Safety course last year with my son to prepare him for the deer season in Wisconsin last fall. That turned out splendidly for him.

One thing the instructor taught us stuck with me. He said (paraphrasing): Look, only about 5% of the population in this country hunts. Opposing us are about 5% of the population who are strongly opposed to hunting for whatever reason.  And the other 90% of the population doesn't really have an opinion on the matter. But a significant part of that 90% votes. And when they do vote, they tend to make up their minds based on personal experiences...things they see and hear...things like "hey, I didn't like the way those guys left all their trash behind," or, "I'm a farmer and those damn hunters wrecked my fence and didn't even ask my permission." On the other hand, some people are really put off by people who just come off badly. They hear and think things like "Man that guy sounds like an arrogant little bigot. I'm not going to vote for his side," or "I can't believe how stupid she sounds. I can't be on her side."

That's one way how little 5% things add up and end up mattering.

Amazing Version Of "Amazing Grace"!

I'd love to see Dick Dale play the Super Bowl halftime show.

Tuesday, February 7, 2012

Conversations with Henry

Henry: "Isoelectronic" is a perfectly fine concept. No need for you to feel it's inadequate. I'll give you an even easier example. We can play the same game with carbon, nitrogen, and oxygen:

[Henry sketches the Lewis structures for N2 and CO]:
Henry:  Forget about the labels "C", "N", and "O" for a moment.  Don't let them color your thoughts. Think of them as the numbers 12, 14, and 16:

Me:  OK, but what does the little curved arrow 1p, 1n mean in your picture?

Henry:  That's your little Maxwell's Demon, moving a proton and a neutron from one side to the other. There's no net loss or gain, but rather just a transfer.

Me: Are you pushing electrons too?

Henry: No! The electrons haven't moved yet but they feel the polarization: suddenly there's an extra charge on the oxygen side and one less charge on the carbon side. The electrons rearrange, being drawn slightly closer to the oxygen, but not completely, and the carbon, having less positive nuclear charge, is polarized negatively by the electrons. The molecules electron's are polarized like this:
Me: Ah, that explains why carbon monoxide binds to metals like iron in hemoglobin via its carbon.

Monday, February 6, 2012

Gallium Arsenide is Germane to Solar Cells

Gallium arsenide, a simple combination of two elements, interconverts light and electricity; GaAs lasers turn electricity into light and GaAs solar panels convert light back into electricity. There are alternative combinations of elements for these tasks, but each has its limits. What strikes me is how gallium and arsenic bookend germanium:
I need a name for "binary combination of elements which brackets and mimics another element." The term isoelectronic is close but doesn't cut it for me. There is a mathematical symmetry about GaAs in view of Ge and it goes like this: (31 + 33)/2 = 32 or, in chemical logic symbols: (Ga + As)/2 = Ge.

Like gallium arsenide, germanium is a photovoltaic material. Google "germanium solar cell" and you will find cutting edge research involving blends of gallium arsenide with germanium. I'm glad there is on-going research into new materials because I am not sure we should be putting arsenic on every rooftop much like we're putting mercury in every lightbulb.

A similar "bookend relation" occurs a couple rows up in the Table between boron, carbon, and nitrogen. Look how boron and nitrogen bracket carbon:

Once again, (5 + 7)/2 = 6. And just like carbon, boron nitride (BN) has both graphite- and diamond-like structures. One type of BN is even harder than diamonds: link

I see a pattern here: the centrality of the carbon group, C, Si, Ge, etc. to the family of main group elements:

Thursday, February 2, 2012

Isn't the guy on the "left"...

...debating Ted Nugent the same guy who got called out for mocking the Santorums in their grief?

Who is that POS?

Wednesday, February 1, 2012

More On Negative Voting

A commenter named revenant made an astute remark over on Althouse:
 Revenant said... 
1. Romney is a bad choice for President.
2. Gingrich isn't Romney.
3. Therefore, Gingrich isn't a bad choice for President.
For the record, the above is the logical fallacy known as "denying the antecedent". The problem is that a lot of people who really ought to know better seem to think it is a valid argument.
1/31/12 10:08 PM

I recast it back in time:

1. McCain was a bad choice for President.
2. Obama wasn't McCain.
3. Therefore, Obama wasn't a bad choice for President.

For the record, the above is the logical fallacy known as "denying the antecedent". The problem is that a lot of people who really ought to know better seem to think it is a valid argument.
My point goes back to a one I made earlier about negative voting, here