Where Does Fat Go When You Exercise? (A Molecular Monday Post)

June 5, 2017

Exercise is good for you, I guess. It’s probably one of the better options for anyone who’s trying to lose weight. But when you exercise, where does the weight go, physically speaking?

The first time someone asked me this question, my best guess was that it had something to do with Einstein’s E = mc2 equation, the equation that allows matter to be converted into energy. But I knew that couldn’t be right. That’s more of a nuclear physics thing, and the human body is not a nuclear reactor.

The actual answer has to do with chemistry. Rather simple chemistry. This is a triglyceride molecule:

Okay, it is sort of a complicated-looking molecule. Don’t worry. Your body knows what to do with it, even if your brain doesn’t.

The important thing, in relation to today’s question, is that triglyceride is composed almost entirely out of carbon and hydrogen atoms, with a few oxygen atoms sprinkled in.

Now when your body exposes triglyceride to the oxygen you breathe in, that highly reactive oxygen starts breaking the triglyceride molecule apart. With each chemical bond that breaks, a little bit of energy is released (allowing you to keep exercising), and the broken pieces of triglyceride recombine with oxygen to make carbon dioxide (CO2) and water (H20).

It’s worth noting that chemical bonds do contribute marginally to the total mass of a molecule, so when you break them and turn them into energy, E = mc2 does apply, sort of. But that’s nowhere close to being a significant factor in terms of weight loss.

The vast majority of the weight you lose comes in the form of carbon dioxide, which you breathe out through your lungs, and water, which you sweat out or pee out or breathe out as water vapor. (If you want to get into the math and find out how many kilograms of oxygen you need to burn how many kilograms of triglyceride, producing how many kilograms of water and CO2, click here.)

When I started studying chemistry, this was not the kind of thing I was hoping to learn. I’m a science fiction writer. I’m interested in the type of chemistry that makes rocket engines go, or drives weather patterns on other worlds, or could make alien life possible.

But still, it’s exciting to me when I can connect all that outer space science to some of the mundane aspects of life here on Earth.

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Today’s post is part of a special series here on Planet Pailly called Molecular Mondays.

On the first Monday of the month, we take a closer look at the atoms and molecules that make up our physical universe, both in reality and in science fiction.

Sciency Words: Basic

May 5, 2017

Today’s post is part of a special series here on Planet Pailly called Sciency Words. Each week, we take a closer look at an interesting science or science-related term to help us expand our scientific vocabularies together. Today’s term is:


During this year’s A to Z Challenge, I ended up covering several scientific terms that do not mean what you might think they mean. Notable examples include reduction, metallicity, and volatile. Basic is another good example, but I already had something else I really wanted to do for B.

Whenever I hear someone talking about basic chemicals, it’s not always clear to me what they mean. On the one hand, basic could mean simple or ordinary.

But basic can also mean fundamental or foundational, as in a base is a foundation upon which you can build something. This gets us closer to what the word means (or should mean) whenever we’re talking about chemicals.

A “Base” for Salt

The modern usage of base and basic in chemistry can be traced back to the mid-1700’s, to Guillaume-François Rouelle, a French scientist who studied the chemical formation of salts. Rouelle found that certain substances, such as alkalis, served as good “bases” for creating salts.

All you have to do is take one of Rouelle’s bases, add an acid, and voilà! you have a salt. And if your base happens to be sodium hydroxide and your acid happens to be hydrochloric acid, you end up with water and sodium chloride, a.k.a.: table salt.

So the next time you run out of table salt but have plenty of sodium hydroxide and hydrochloric acid around, you know what to do!

A “Base” for Protons

Our understanding of acid-base chemistry is a little more sophisticated today than it was in the 1700’s. Rouelle wouldn’t have known about protons, for example. Fortunately, the original terminology still makes a certain sense, even after we learned of protons and the role they play in acid-base reactions.

In most cases (excluding Lewis acids and Lewis bases), an acid can be thought of as a molecule with a proton dangling loosely off the side. This dangling proton will break off at the first opportunity, so long as the proton can find a better place to go.

In this context (again, excluding Lewis acids and Lewis bases), a base can be thought of as a molecule that can accept a proton that has broken free of an acid. In other words, it’s the “base” upon which the proton can land and make a new home for itself.

Basic Chemicals Aren’t So Basic

So if you hear someone talking about basic chemicals, you might want to ask for some clarification. By “basic,” do they mean (wrongly) a common or easy-to-make chemical, or are they talking (in a more proper sense) about acid-base chemistry?

Molecular Monday: Why Chemistry?

May 1, 2017

The first Monday of the month is Molecular Monday here on Planet Pailly!

We just wrapped up this year’s A to Z Challenge, and I ended up writing a lot about chemistry. A lot more than I expected. You’d think I must really love chemistry.

But I don’t.

I really don’t.

For a long time, I tried to avoid the subject completely due to bad memories from high school chemistry. My professor was extremely generous in giving me a just-barely-passing grade.

So when I made the commitment to include more science in my science fiction, I figured I could get by with just the “fun” sciences like physics and astronomy. Then in 2015, I did my yearlong Mission to the Solar System, and the planet Venus forced me to start learning this chemistry stuff.

As you can see in this totally legit actual Hubble image, Venus has some very special chemical activity going on.

There’s simply no way to understand what’s happening on Venus without getting into the weird sulfur chemistry of the Venusian atmosphere. But once you do make sense of that sulfur chemistry, a strange new world is suddenly open to you: a world of both heavenly beauty and acid rain hellfire death.

Since my experiences with Venus, I’ve come to realize that understanding chemistry, even at a basic level, makes my work as a science blogger and science fiction writer so much easier.

  • Is there life on Mars or Europa? What about life in other star systems, or silicon-based life? If alien life is out there, it will be the product of chemistry.
  • What about humans traveling to other worlds? What would be safe for us to eat or breathe? Chemistry can help answer that too.
  • Venus isn’t the only world defined by chemistry. Earth has been shaped in large part by the chemistry of oxygen and water; the gas giants by ammonia and methane; and then there’s a true oddball like Titan with its tholen chemistry.
  • And how am I going to get my rocket ship off the ground? By mixing rocket fuel. In other words, by doing chemistry.

Chemistry is by no means the most fundamental science, but for the kinds of things I write, it is the most applicable science. So even though I don’t enjoy the subject, I’ve forced myself to stick with it.

And if I’m being perfectly honest, in those aha-moments when complex chemical reactions suddenly makes sense to me, I may quietly murmur to myself, “Okay, chemistry is kind of fun.”

Sciency Words: Volatile (An A to Z Challenge Post)

April 26, 2017

Today’s post is a special A to Z Challenge edition of Sciency Words, an ongoing series here on Planet Pailly where we take a look at some interesting science or science related term so we can all expand our scientific vocabularies together. In today’s post, V is for:


Whenever I hear somebody talk about volatile chemicals, I’m never quite sure what they mean. This is another case of a word that means one thing to the general public and something rather different to professional scientists.

In chemistry, a volatile chemical—also refered to simply as “a volatile”—is a chemical substance that tends to evaporate spontaneously under ordinary temperature/pressure conditions. A common example of a volatile here on Earth is water.

Of course you may encounter other chemicals here on Earth far more volatile than water. Just think about alcohol or gasoline. You might also think about nitrogen, oxygen, or hydrogen, because if you manage to get these chemicals into their liquid phases, they will immediately turn back into gases at the first opportunity. That makes them extremely volatile.

To be clear, the volatility of a chemical has nothing to do with how flammable, explosive, reactive, or unstable it is. That may seem a little confusing, but unlike previous confusing chemistry terms we’ve seen (like organic or reduction), I’m not sure I can fault chemists for this one. The chemistry definition is actually closer to the original meaning of the word; in a sense, it’s the rest of us who’ve been using the word wrong.

When volatile first entered the English language from French, it could mean either “light weight” or “evaporating quickly.” The “violent and unpredictable” meaning didn’t come until later. If you go further back into the word’s history, you find it derives from a Latin word meaning “to fly away,” which is actually an apt description of what atoms and molecules do when a volatile chemical evaporates.

Next time on Sciency Words: A to Z, the WIMPs will take on the MACHOs. Which acronym will win?

Sciency Words: Reduction (An A to Z Challenge Post)

April 21, 2017

Today’s post is a special A to Z Challenge edition of Sciency Words, an ongoing series here on Planet Pailly where we take a look at some interesting science or science related term so we can all expand our scientific vocabularies together. In today’s post, R is for:


In his book Atom: Journey Across the Subatomic Cosmos, Isaac Asimov writes:

It often happens that a poor name is given to an object or a phenomenon to begin with, either out of ignorance or out of bad judgment. Sometimes, it can be changed in time, but often the ill-chosen name is used so commonly by so many that it becomes inconvenient or even impossible to change it.

Hank Green says much the same thing at the beginning of this episode of Crash Course: Chemistry on oxidation and reduction.

I wish someone had told me this in high school chemistry, because I could never make sense out of reduction. The name confused me too much, because it means the opposite of what it should mean.

Some atoms are naturally greedy for electrons. These atoms are called oxidants.

And some atoms are naturally well inclined to give electrons away. These atoms are called reductants.

When a reductant gives an electron to an oxidant, the reductant is said to have been oxidized. And when an oxidant gains an electron from a reductant, the oxidant is said to have been reduced.

Yes. The gaining of an electron is called reduction, a word typically associated with the losing of something. Just… how even? This is one of the most fundamental reactions in all of chemistry. No wonder chemistry is so notoriously hard!

Apparently long ago, it was observed that some substances become lighter after undergoing a chemical reaction. Hence, reduction. We now know the substances in question were gaining electrons (which weigh practically nothing), while incidentally losing other, heavier things in the form of gases. But how were scientists of the 18th Century supposed to know that?

We can take some consolation in the fact that when a chemical substance gains electrons, its oxidation number goes down. So in that sense, the word reduction doesn’t seem completely stupid.

But Asimov and Green hit upon a key insight on how scientific terminology works—or rather, why it doesn’t always work. When you really delve into the scientific lexicon, you find this naming before understanding trend everywhere. As a result, we’re now stuck with a ton of confusing, counterintuitive names for important scientific concepts.

Next time on Sciency Words: A to Z, we’ll jump feet first into a black hole.

Sciency Words: Organic (An A to Z Challenge Post)

April 18, 2017

Today’s post is a special A to Z Challenge edition of Sciency Words, an ongoing series here on Planet Pailly where we take a look at some interesting science or science related term so we can all expand our scientific vocabularies together. In today’s post, O is for:


Sometimes scientists name things before they fully understand them. Such is the case with the entire field of organic chemistry.

Organic chemicals are called organic because, it was once thought, they could only be produced by living organisms. There was something almost mystical, almost magical about living things, scientists believed. They spoke of a mysterious “vital energy” without which certain chemical reactions simply could not occur.

Then in 1828, Friedrich Wöhler synthesized urea–a key ingredient in urine–in a test tube. That sounds kind of gross, but it was a monumental achievement in the history of science.

Sort of like how Newton showed that the same laws of physics which apply here on Earth also apply to the planets and stars, Wöhler’s urea synthesis demonstrated that the same laws of chemistry apply to both living and non-living matter.

The group of chemicals that scientists had been calling “organic” do have at least one thing in common: carbon. They all incorporate carbons atoms, typically carbon atoms bonded to other carbon atoms or to hydrogen atoms (certain simple carbon compounds like CO2 are generally not considered organic).

Perhaps some other name would be more appropriate for these complex carbon molecules, but scientists had been calling them organic chemicals and talking about organic chemistry for a while. The name had already stuck.

I suppose we could rationalize the modern usage of organic by saying we organisms need organic chemicals to live; but thanks to Wöhler, we now know organic chemicals do not need us organisms in order to exist.

Next time on Sciency Words: A to Z, let’s see if we can get Pluto’s planet status back.