Category Archives: chemistry

It’s a Chemical Universe

Have you ever heard someone say something dismissive about chemicals? Like comments that indicate these substances are somehow separate from us? It’s pretty common to see some people advocate for “natural” or “organic” products. Or, they preach against vaccinations because they wrongly assume these lifesaving injections are somehow “full of toxins and chemicals”.

It always sounds so silly, to me. I mean, the entire detectable universe consists of chemical elements. That means you and me and the planet and the Sun and Moon and… well, everything we can directly detect. So how can substances or objects consisting of chemicals be somehow unnatural?

Yes, I get that these people are often referring to specific things in vaccinations, for example. (Things that aren’t there, by the way. Or, they’re completely misunderstood or misinterpreted by people with a lack of critical thinking skills. But that’s a different topic.) That old argument about chemicals being somehow “unnatural” and “toxic” just ignores the reality of our existence.

Chemical Ingredients for Life Are as Old as the Universe

Take a look at your hand. Or the apple you’re eating. Or the coffee in your cup. And, the cup itself. Every object you can sense is made of chemicals. Or, to be more specific, chemical elements combined into molecules. Those are, themselves part of some kind of cellular matrix. I always liked the bit in the first “Cosmos” series where Dr. Carl Sagan suggested that, “If you wish to make an apple pie from scratch, you must first invent the universe.”

It’s true. The apple is a construct of atoms of elements that formed complex molecules. They combine to make the apple’s structure. So is the crust. So is the sugar (if you use that), and so are the other ingredients. And, so are all the things inside vaccines. In some cases,they have killed viruses that we wish to inoculate against. And, the viruses themselves are incredibly complex mixtures of molecules made of chemical elements.

Space is where we come from, it’s where the chemicals of life originate and spread seed to places where life can thrive. NASA/Jenna Mottar.

So, where do those “fixin’s” come from? Why from the stars, of course. Other than hydrogen and a little lithium, most other chemical elements come from stars. So, calcium (for your bones), iron (for your blood), potassium (to regulate heart activity), and other elements, come from stars. They cook them up as they age and evolve, and when they die, stars scatter that “stuff” to the universe. There, it gets taken up (eventually), into clouds of gas and dust, which are the birthplaces of stars and planets. And, planets (as we suspect from our sample of one) are formation places for life.

Chemical Clouds Hold Clues to Life

We know that interstellar clouds contain hydrogen. That element was created in the Big Bang. The clouds also harbor complex organic molecules. Many of those substances are actually the building blocks of life. And, they seem to be in many such cloud complexes.

Astronomers, astrobiologists (the folks who study life elsewhere), and astrochemists (who study chemical elements in the universe) want to know how soon in the universe these molecules appeared. What causes their formation? In a disk of gas and dust, when do the building blocks of life appear? One suggestion is that they form in response to rising heat and pressures in a protoplanetary disk. That’s the part of the cloud where a star and its planets are born.

When Do Chemical Percursors Form?

At least one study shows that those complex organic molecules can exist long before a protostar begins to form. In that research, scientists found molecules of methanol and acetaldehyde in a large number of starforming regions called “pre-stellar” or “starless”. These places don’t have stars, yet. However, they seem to be places where cold dust and gases coalesce. There, they form the seeds that eventually will give rise to stars (and planets). And, according to the scientists who are studying these regions, they contain life’s building blocks, before worlds exist to take advantage of them.

These two molecules aren’t the only prebiotic precursors found in such clouds. A simple sugar molecule called glycolaldehyde has been detected, along with a host of other carbon-based molecules. These discoveries show us that we are in a chemical universe that provides the seeds of life.

Finding Chemical Precursors

To study the clouds for their particular discovery, a team of scientists at the University of Arizona’s Steward Observatory, used a 12-meter dish telescope to study emissions from interstellar clouds. They peered at 31 starless cores scattered throughout a star-forming region known as the Taurus molecular cloud. That cloud lies about 440 light-years from Earth. Each core is quite large, about the width of a thousand solar systems. None of the cores has a star at its heart, and probably won’t for several hundred thousand years.

That’s according to Yancy Shirley, who worked with graduate student Samantha Scibelli on the project. “This tells us that the basic organic chemistry needed for life is present in the raw gas prior to the formation of stars and planets,” he said. The processes that bring chemical elements together to form organic molecular building blocks of life aren’t well understood. “The exact processes at play are still being debated because the theoretical models still don’t quite match what we see,” Scibelli said. With the current research, she and the team can constrain the formation sequence that might be taking place in the clouds.

Their work will tell theorists how abundant these molecules are. Eventually, it may be possible to figure out exactly how these molecules form and why they exist where they do. That would open up a wider range of places to study the chemicals that create life. (You can read more about this specific research here.

Accepting a Chemical Universe

It’s thanks to the prebiotic molecules that formed in our local neighborhood that we even exist today. Studies like the one at Arizona are the first steps toward trying to figure out where life exists elsewhere. Even more intriguing: it plays a big role in revealing where life could form next. And, we have chemical elements to thank for it. We’re all made of star-stuff, which is, in turn, made of chemicals. So, now I wonder, what could be more natural than chemicals? After all, they’re what we are.

One Is the Loneliest Number

Or Is It?

I had to do a bit of a long drive today and while I was tootling along in the car, I heard the old Three Dog Night song written by Harry Nilsson called “One is the Loneliest Number”. And as is my usual case, that set me to thinking about all kinds of things, including…  the number 1.

Mathematically, 1 is an interesting entity.  First, it stands for a single thing.  Sometimes we refer to it as “unity”.  It’s the first non-zero whole number, and if you multiply any other number by 1, you get that number.  You get an “identity”.  So 1 x 1 = 1, 1 x 50 = 50, and so on. It’s an odd number, meaning it can’t be divided evenly by 2. There’s lots to know mathematically about 1, which you can read here.

1 (one) gets a lot of play in cultural references — like in the song I mentioned above.  Who hasn’t heard of Neo being “the one” (in The Matrix), or calling someone your “one and only” in a romantic setting?

In binary code, 1 is one of two pieces in a base-2 system of counting (the other being zero).  The binary system is used by all computers, which is where you often see the term “ones and zeros”.

This image of the spiral galaxy NGC 2841 began as data--a series of ones and zeros transmitted back to Earth from Hubble Space Telescope. Courtesy STScI.

In astronomy these days, all the digital imagery and data you see streaming from various instruments is in the form of “ones and zeros” which get encoded into the pictures and graphs we see.  Astronomers use fairly complex computer programs to decode the images, apply algorithms to remove errors and data dropouts, and colorize, sharpen, mask, or other imaging processes to help them understand what they see in their images and data.

Astronomy brings me to an interesting element: hydrogen. Yes, it’s also part of what we study in chemistry when we learn the elements. In fact, hydrogen is the chemical element with the atomic number 1. But, when you start to study the universe in astronomy, you very quickly run into hydrogen, which means you quickly learn about it as a chemical element.

The most abundant isotope of hydrogen (think of “isotope” as “form”) has one proton in its nucleus and no neutrons.  Hydrogen, element number 1, is the most abundant chemical element in the universe. An astounding 75 percent of the normal matter in the universe (not including dark matter) is hydrogen, and 90 percent of the atoms in the universe are hydrogen. When you look at stars, or nebulae, or the planet Jupiter for that matter, you’re seeing LOTS of hydrogen.  In clouds of interstellar gas and dust where stars are born, for example, the hydrogen is in the form of a gas — H2. It’s in what’s known as the “molecular state”, where atoms of hydrogen bond to form molecules of the gas. Hydrogen also exists as free atoms, and also in an energized (think: heated) and magnetized state called a plasma.

Molecular structures of the 21 proteinogenic amino acids (click to enlarge). Courtesy Dan Cojocari under a Creative Commons Atribution-Share Alike 3.0 license.

As befits an element whose number is 1, hydrogen was the first element created in the Big Bang. Within moments of that creation, heavier isotopes of hydrogen came about (like deuterium) and then forms of helium and lithium. But hydrogen was number 1 in the beginning.  And, judging by its abundance throughout the cosmos, it’s still number 1. It’s what you need to form stars (from those gas clouds), it is an essential component of many chemical compounds like water (H2O), or amino acids (see the image to the right).

YOU are largely made of water, and thus your body has a great deal of Element Number 1 in it. All life on this planet dabbles in water, evolved in water, and uses water to survive. There are billions and billions of life forms on Earth, and they all depend in some way on water, which is mostly hydrogen.

That hydrogen link gives us a common bond with the rest of the cosmos — the single atomic and elemental link that stretches back across more than 13.7 billion years to when the first atomic particles of hydrogen came into being and began the dance of cosmic evolution.

So, in a sense, while 1 may be the loneliest number, because of hydrogen, we are all one with the universe in a very elemental and scientific way.