History of the Atom: Footnotes

You’re either here because you’re interested in learning more about something on another page, or because Google mistakenly sent you here.  Either way, the following are footnotes from the various atomic history pages on my site.

1.  Diogenes (412-323 BCE) once said that he “threw my cup away when I saw a child drinking from his hands at the trough.” People treat this as wise, but it could also be the case that it’s wise in the same way that weird fortune cookies are wise.

2.  Lots and lots of other people had ideas about the nature of matter, too, but they usually get ignored in chemistry textbooks.  Plato thought that differently-shaped atoms had different properties, while Aristotle argued that basic substances simply gained new essences when they were shaped into something else.  Furthermore, there were other Greeks who had deeply philosophical thoughts about matter, as well as people from other cultures who pondered the same things.  Finally, stoners frequently explore this topic, resulting in inane nonsense posted in their blogs the next day.

Fig1poetry

 

 

 

 

 

3.  It seems likely that Luther’s personality made the situation worse than it should have been.  Though undeniably a great thinker (he was a theologian, wrote many hymns, and translator of the Bible), he also had some serious mental problems, among them near-suicidal depression and possible obsessive-compulsive disorder.  It’s also thought that the angry and outraged tone of his writings may have hastened his excommunication.

4.  Said Proust:  “I shall conclude by deducing from these experiments the principle I have established at the commencement of this memoir, viz. that iron like many other metals is subject to the law of nature which presides at every true combination, that is to say, that it unites with two constant proportions of oxygen. In this respect it does not differ from tin, mercury, and lead, and, in a word, almost every known combustible.”  Incidentally, depending on source, Proust was said to have discovered this in 1793, 1797, and 1798. If you’ve seen the movie Groundhog Day, you can imagine how annoying that must have been.

5.  This is actually true.  Well, sort of.  Studies have shown that since 1930, the average intelligence of military recruits, as measured by IQ tests, has steadily increased.  Thus, the Flynn effect (as this is called) is said to demonstrate that average intelligence is steadily rising.  Of course, there are excellent arguments that IQ tests don’t accurately measure intelligence, and the sample of recruits is hardly representative.  However, this trend allows me to make a joke about John Dalton, which is the whole point.

6.  In 1989, two scientists named Pons and Fleischmann announced in a press conference that they had fused atoms of deuterium using electrochemical methods.  It turns out that there’s a very good reason that you get things like this published and reviewed by other scientists before releasing it to the public:  If you say that something amazing has happened and you’re wrong, you look like a moron.  By the end of 1989, basically everybody had shown that their results were stupid and had taken to openly mocking anybody who had a part in these results.  Not all was lost, however, as Pons and Fleischmann (but not their careers) live on as a wonderful example of how not to do science.

7.  There are minerals that don’t live up to either the law of definite composition or the law of multiple proportions.  These compounds are called “non-stoichiometric compounds” and have varying composition depending on where they were made – additionally, the composition may not involve nice whole numbers as in the example.  This phenomenon usually takes place in crystals, where some of the spots that should be filled by atoms are left empty.

8.  The Claisen rearrangement is the first reaction of this type that comes to mind (though there are certainly others).

9.  Thomson didn’t actually come up with the “plum pudding” name, though I haven’t been able to figure out who it actually was.  So we’ll just say it was Thomson anyway, because you can’t make fun of people with unknown identities.

Fig2Cabbagepudding

10.  There was actually some question about what the electrons were actually doing inside of the big ball of positive charge.  Some people thought they drifted, while others thought they orbited around.  In any case, the model was disproved in 1911, so it wasn’t discussed for long.

11.  In almost every textbook, people mention that Rutherford was from New Zealand.  I have no idea why this would be the case.  However, I have two guesses:

  • People think that New Zealanders are so awesome that this is just a typical example of their awesomeness.
  • People think that New Zealanders are kind of slow, so they’re amazed that somebody from New Zealand could do stuff this cool.

Personally, I haven’t noticed that the average New Zealander is all that different from anybody else, aside from the accent.  By the way, if you want to watch a cool TV show from New Zealand, check out This is not my life, which can be streamed on Netflix.

12.  This photo is actually of Ted Nugent, a.k.a. the “Motor City Madman.”  Among other things, Mr. Nugent once threatened to shoot a Hare Krishna in the spine.  Mr. Nugent is active in conservative politics and is an avid bowhunter.  Plus he’s nuts.  But a hell of a guitar player.

13.  One of the big unanswered questions that students have is “What happened to Marsden and Geiger, the people who actually did the experiment?”  As it turns out, they were Rutherford’s employees:  Marsden was one of his grad students, and Geiger was a post-doctoral fellow.  It is usually the case that when a professor’s students make a discovery, that the professor gets the credit, usually because he’s the guy who came up with the idea and told them to do the experiment in the first place.  That these experiments are every referred to as the “Geiger-Marsden experiments” is kind of miraculous.  Anyhow, here’s some information about what eventually happened to these two:

  • Geiger, along with a guy named Nuttall, improved radiation detectors, which are now referred to as Geiger counters.  He went on to professorships in Germany and eventually worked on the German atomic bomb project.  It’s not clear whether Geiger was a Nazi sympathizer – the best guess is that he wasn’t and that he just wanted to do cool science.
  • Marsden briefly had a physics professorship, and then served in the British army during world war I on scientific projects.  After the war, he organized agricultural research for a while, followed by research in various nuclear technologies.  Eventually he came to speak out against nuclear testing, though it doesn’t appear that anybody paid much attention to this.  He, too, was a New Zealander;  despite this, he wasn’t as cool as Rutherford.

14.  Some things are even weirder and contain either both (in which a continuous spectrum has brighter lines in it) or something even weirder, such as the Fraunhofer lines in the solar spectrum (the solar spectrum has dark gaps that correspond to absorption lines, which are closely related to the phenomenon later in this tutorial).

15.  As it turns out, incandescent light bulbs do a good job of illustrating how only very hot objects give off visible light.  Though the tungsten filaments in light bulbs are able to give off a great deal of light, it turns out that over 90% of the emitted energy is less energetic than this and is emitted in the form of heat.  This is why fluorescent bulbs are so much more energy efficient than incandescent bulbs:  The process by which light is given off is different, resulting in much higher efficiency in converting electricity to light.

16.  I’ve had people complain to me before when I say things like “atoms like to…” or “electrons like to…” do things because it’s making it sound as if atoms or electrons are thinking beings.  My usual response to these arguments include the following:

  • Saying “like” and “dislike” make it convenient to visualize what’s happening.
  • Students aren’t idiots, and already know that atoms and electrons aren’t little people.
  • It’s clear from context that “like” infers a tendency to do something, while “dislike” infers a tendency to not do something.
  • Stop being such a weiner.  Seriously, is this the biggest thing in life you have to worry about?

Generally speaking, the kind of people who email me believe that yes, this is the biggest thing in life they should worry about.

Fig3IED

17.  This statement is, like most things involving the atom, an oversimplification.  Not only are there more valence electrons in most elements, but higher energy orbitals are closer together in energy than low-energy orbitals.  As a result, there are typically more excited states available to electrons in higher ground states than in low energy ground state electrons.

18.  There are actually more shortcomings than the one I mentioned, though that’s the biggie that we usually comment on.  Additionally, it’s not exactly right to say that the model works only for hydrogen atoms, as it actually works for any single-electron atom such as He+.  However, given that this is not a particularly common or useful ion, this discrepency mainly serves to remind us that the model needs some work.


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