TANGENTS: We’re not letting Casey Camire off the popular-science hook yet. This week, we’re going to talk about chemistry in our lives. Casey, please define chemistry and tell us a little about the field’s invention.
CASEY: Fundamentally, chemistry is the study of matter. And, since matter makes up everything in existence, chemistry touches nearly every aspect of existence. As such, humans have been doing chemistry of one form or another from the very beginning. From our earliest days getting fire sorted out, through the ages named for their respective metallurgies, humans have been manipulating matter to suit their needs the entire time there have been humans.
As a proper scientific discipline, however, chemistry didn’t get its start until the 18th century, but it did have roots in the earlier pseudoscience/mysticism known as alchemy. Alchemy, while popularly known for its aim of turning anything into gold, also experimented with perfecting an elixir of immortality, among other fantasies. Alchemy was practiced by many ancient civilizations in and around the Hellenistic world, and was picked up by Islamic civilization, from which it was reintroduced to the West during the early Enlightenment. Until this point, most chemical theories were centered on a four-element system (earth, wind, fire, and water), which had been popularized by classical Greek philosophy. Western rediscovery of alchemical ideas coupled with the beginnings of modern science eventually gave rise to chemistry proper.
Antoine Lavoisier is generally considered the father of modern chemistry. By thoroughly disproving the existence of Phlogiston (which is itself a fascinating read), he placed chemistry as a field on more solid ground, and it is his quantitative approach to chemistry, rather than a qualitative one, which finally led to the maturation of chemistry as a field. In short, Lavoisier began conducting experiments, which produced measurable results instead of interpretive ones. As such, the results of chemical experimentation were less subject to personal interpretation, and reproducibility, the key to any scientific inquiry, was established in the chemical world.
What made chemistry more difficult to establish than other scientific fields is how counterintuitive it is. Its most fundamental unit is the atom, a bizarre, impossibly small thing, which behaves like both a particle and a wave, is itself composed of sub-particles which determine the way it behaves with other atoms, is more than 99% empty space, and comes in a variety of flavors whose properties seem to repeat themselves every eight protons or so. The atom is composed of three kinds of subatomic particles, protons and neutrons, which are found in the center, or nucleus, and electrons, which are found outside of the nucleus in what are called atomic orbitals. It wasn’t until discrete atom types, which we call elements, were discovered that chemistry could really find any sort of footing. An element is a pure substance whose properties are determined by the number of protons in the nucleus. What was so tricky about all this is that most of what we interact with are molecules, which is a substance composed of atoms bound to each other. At an everyday scale, atoms and molecules can be difficult to distinguish from one another, and it is very difficult to just pluck a single atom off of a molecule. Once the basic elements were firmly established, chemistry was off and running.
Today, chemistry can be divided into three broad sub-fields. Physical chemistry concerns itself with the interface of chemistry and physics. Utilizing quantum theory, it can be used to do extraordinary things like determine molecular structure and composition. Keep in mind how remarkable that is – we can, through careful analysis, determine the structure and composition of molecules. The second sub-field is known as organic chemistry, and concerns itself primarily with the chemistry of carbon, oxygen, and nitrogen, and very often sulfur and phosphorous. It got its start in the late 19th century and, as the name suggests, has roots in what was known then as the chemistry of life. Inorganic chemistry, its cousin and complement, concerns itself with the chemistry of the remainder of the periodic table. While inorganic and organic chemistry began as more or less distinct fields, the lines that separate the two have blurred and there is much exchange between them.
Applied chemistry has, among many other subfields, the field of analytical chemistry. Analytical chemistry is incredibly useful. If the question you need answered can be boiled down to “What is this?” or “How much of that is there?” you can bet analytical chemistry will be applied to get the answers you need. It is absolutely essential to the function of every industry, and is where many, many chemists find lifelong employment.
As a discipline, chemistry is known as the central science. It exists at the crossroads of the two other fundamental sciences, physics and biology, and a chemical education benefits from that position. Thermodynamics, the study of how energy flows within systems, and kinetics, the study of how fast things reach a steady state, are concepts from physics that most influence an undergraduate understanding of chemistry. Essentially, they train the chemist to think of everything as a system seeking its most comfortable state. Hot to cold, order to disorder, positive to negative, these fundamental principles drive the resting position of all systems and can be used to understand, and manipulate to our advantage, the world around us.
TANGENTS: I never knew chemistry studies matter in all forms, probably because movies always show “chemists” studying liquids in test tubes and nothing else. How do you think the public misunderstands chemistry?
CASEY: That’s a common misunderstanding! But it’s not entirely inaccurate either. Much of what we chemists to is so-called “wet chemistry,” which means we’re using solvents (and sometimes solids) to isolate and purify the subject of our current chemical investigation. As such, glassware (especially spotless, perfectly shiny, very dry glassware) is indeed close to a chemist’s heart.
As far as public misunderstanding of chemistry goes, by far the largest misconception is exactly what a “chemical” is. Very often these days you hear people complaining of “chemicals” in our food, and in our consumer goods in general, while urging for those “chemicals” to be replaced with something “natural.” But the thing is, everything is a “chemical!” There’s a popular gag that involves calling water “dihydrogen monoxide” and stating facts along the lines of “Everyone who has ever consumed dihydrogen monoxide has died or will die,” and “Every single criminal has consumed dihydrogen monoxide in their lives,” which are strictly true but obviously sensational if the reader is clever enough to realize this. The gag’s punchline is then asking the reader whether they would support removing dihydrogen monoxide from daily life.
Unfortunately, by using a scary chemical name, it is often much easier for those who do not understand chemistry to malign materials which make life objectively better. This has very serious real-world consequences – think “mercury in our vaccines causes autism.” The challenge here for chemists is bringing a certain sense of chemical literacy to the public at large. Unfortunately, anything vaguely chemical-sounding has an immediate negative connotation these days, so that challenge is a daunting one.
TANGENTS: Yeah, I suppose that chemical warfare since the First World War has really soured the public on the word “chemical.”
CASEY: Well, I’d argue that the public was pretty convinced of “Better living through chemistry” (Dow Chemical’s tag line through the 1960’s) and it wasn’t until the ‘70s and ‘80s that things changed. Not for bad reasons! The emergence of environmentalism as a serious (and necessary) political movement, in addition to the atrocious chemical record of the Vietnam War, called into question how much we had trusted our chemical sector. It is in light of those things that I urge in the strongest some kind of chemical literacy – fear only keeps one in the dark.
TANGENTS: What’s the difference between a chemist and a chemical engineer?
CASEY: Finally a short answer! A chemist is concerned with conducting the science of chemistry. A chemical engineer is concerned with the process of manufacturing chemical products. What requires the engineering are the problems presented with scaling up chemistry useful to industry. Making 100 grams of a product is very different than making 160,000,000 grams of it!
TANGENTS: Fair point. Do you have chemical do’s or don’ts that people should bear in mind? Any household products never to mix?
CASEY: As far as chemical do’s and don’ts go, all I can advise is read the labels carefully for any warnings! Companies have a vested interest in making sure the latest household chemical related disaster isn’t from their household product. Beyond that, utilize the same rules any good bench chemist does: Don’t eat it, keep it labeled, and when in doubt throw it out (in an environmentally responsible manner, of course).
Oh, and watching some good YouTube pop-sci channels can’t hurt either. Periodic Videos is a chemistry-focused channel, Khan Academy has wonderful tutorials on nearly everything, and even MIT publishes the full-length lectures for entire courses for their lower level chemistry classes.
TANGENTS: Haz-mat suit optional?
CASEY: Haz-Mat suit optional!
Cover Photo Source: http://bit.ly/1KozHdw.