Science for SciFi: Astrobiology

Rubber-forehead aliens are basically a meme at this point. They make perfect sense in terms of production costs and limitations imposed by special effects technology at the time. The good news is that writing for print gives us far more options than would be possible otherwise. I think that they make it easier to relate to characters on screen but making all of your aliens look like humans with a few extra bits glued on requires a lot of worldbuilding to explain away. If you try to explain it that is.

The point of this post is not so much to provide an explanation of how life on other worlds could work but rather why it’s so hard to envision what life on other worlds could be like. This is because a) I am not a biochemist and b) it’s somewhat difficult to pin down just what “life” is. Once you’ve wrapped your head around this second idea and thought about some of the strange chemistries that are possible on alien worlds you will feel much freer to imagine strange new forms of life.

At this point, you are probably getting ready to type an angry comment or tweet along the lines of “WHAT DOES HE MEAN? OF COURSE WE KNOW WHAT LIFE IS. I’M ALIVE AREN’T I?” It’s actually a lot more complicated than that. Here on Earth we still have trouble deciding whether viruses are alive. Sure they can infect hosts and they use the same DNA/RNA coding that we and the rest of life here on Earth do, but they lack the machinery needed to make copies of themselves so they have to hijack ours. NASA has a definition of life that they use in the search for extraterrestrials and it’s probably the best one available to us, but there are still likely to be some who disagree with the definition.

“Life is a self-sustaining chemical system capable of darwinian evolution” – NASA

I’d be interested to hear whether readers think that viruses are included in this definition or not.

The reason that the definition of life is so hard to pin down is that we only have our own world to serve as a reference. In our solar system of eight planets and who knows how many planetoids and moons only one body, Earth, is known to support life. Yet there are two other planets, Mars and Venus, that might have once supported life and several moons that could even harbor life this very moment (I’m looking at you Europa).

We can look around at our own planet and describe how life works here. We can explain how DNA works, how organisms obtain energy, and how one organism gradually evolves into another over time. We know all that but we still do not know how life began on this planet. Without knowing how life began it is hard to definitely say whether a planet could support life or not. We tend to get excited when we find planets around other stars that could support conditions similar to those here on Earth, but when we talk about whether a planet is in a star’s “Goldilocks Zone” what we are really saying is that the planet could support life that is like us, and that’s a little arrogant I think.

Fortunately, our knowledge of chemistry and physics allows us to envision other ways in which life might arise. We are, after all, just bags of chemical reactions that happened to develop egos.

Excuse Me, Is This Life Organic?

These days a lot of people think that if something is organic it was produced from “natural” materials or grown without the use of certain fertilizers or pesticides. What they don’t realize is that oil is both organic and naturally occurring, but you wouldn’t want to eat it. When scientists say something is organic all that means is that it is composed of primarily carbon and hydrogen along with a smaller proportion of other elements.1

We and all the living organisms that we know of here on Earth are built out of carbon. Our DNA, our proteins, our hormones, our cell walls. Every bit of biochemical machinery that makes us is built on a scaffolding of carbon. Organic compounds are so prevalent in living things that the distinction between organic vs inorganic chemicals was originally based on whether they had come from a living thing or not.

Carbon is useful in all these ways because each carbon atom can form up to four bonds with other atoms. Carbon can form long chains with other carbon atoms and can also form double and triple bonds not only with itself but with other elements important to Earth life including both oxygen and nitrogen. Silicon is often suggested as a possible substitute for carbon on alien worlds, but silicon is less versatile than carbon and many of its compounds are unstable. This combined with the prevalence of carbon among molecules found in space does not bode well for silicon’s chances. There is however the clay hypothesis that has to do with the beginning of life on Earth.

Another point in carbon’s favor is that by now many complex organic molecules have been detected in space in molecular clouds around stars and on the surfaces of comets. Many of them being the same molecules used by living things here on Earth. With ready-made materials out there in the cosmos, why not take advantage of them?2

Water? I Hardly Know Her

Water is a really great solvent for life on our planet. Besides being everywhere and thus the most logical choice for life solvents, its properties allow both acid and base chemistry to take place. When we begin to consider different temperatures, pressures, and chemical makeup, a number of other solvent options become clear.

All it takes is a solvent that allowed for acid-base chemistry to take place. Water allows this, but there are other solvents that could, under different conditions, or with different commonalities. Waters is ubiquitous on Earth, but it doesn’t have to be on other planets.

Take a look at different solvents. Or familiar gases that would be liquid at other temperatures. The possibilities might surprise you.

Eating Sunshine (And Other Things)

Here on Earth, most ecosystems arise from the energy provided by the Sun. Just about everything either harvests light through photosynthesis or eats something that does. But even on Earth, we know that this is not the only option. In the deepest parts of our oceans, we have found extremophiles that feed off the heat and chemicals released by volcanic vents.

That is just on Earth. There are many sources of energy in the universe including gravity and magnetic fields. Alien life forms could catalyze the synthesis of vital metabolites using alpha and beta particles released by radioactive minerals to catalyze reactions or construct molecular machines on their cell membranes that harvest hydroelectric power.

The Galactic Habitable Zone

It’s weird to think that there might possibly be a shortage of resources on a galactic scale but once you get an idea of how elements are made it begins to make sense.

Basically, there is a band with indeterminate boundaries somewhere between the center of the galaxy and the edge that makes up the galactic habitable zone, a region that is determined by metallicity, the age of the stars, and how often stars in the area go supernova.

The center of the galaxy with its high concentration of stars is considered unsuitable for life, as the frequent supernovae release bursts of radiation that would sterilize nearby worlds and make the development of life difficult, if not impossible. Meanwhile, the edge of the galaxy is full of younger stars that have not had time to transmute the heavier elements that life needs.

All this results in an uncertain band looping around the galaxy where planets are more likely to be habitable. The boundaries of this band are uncertain, but

Turning The Weirdness Dial Up to Eleven

A lot of us tend to base alien species on the species we are familiar with here on Earth. A quick look at some extinct species will show that there are many, many variations on how weird life can get just on a single planet. Just because it didn’t happen HERE doesn’t mean it can’t happen SOMEWHERE.

In all honesty, it just depends on how strictly you want to adhere to known science. You could have aliens with bones like ours with gelatinous flesh or stationary mollusks that spend their days exploring complex algorithms in their minds.

Hard science fiction is all about finding plausible explanations based on what we know now. That doesn’t mean it can’t be weird.

Conclusion

If anything should be clear by now it’s that nothing is. The Milky Way is a big place and we can envision so many possibilities that it is just about impossible to anticipate all the possible variations of life. In fact, I came across so much information while reading this post that I wasn’t able to include it all in this one post. So stay tuned for future posts on the origins of life, panspermia, and whatever else catches my eye in the process.

Notes

  1. Unfortunately for myself and other inorganic chemists. Our field is literally defined as “not organic” which makes it more than a little hard for someone to guess what we do.
  2. I’ve come across a wealth of information on this topic and it’s all incredibly facinating. Enough so that I’ll probably have future posts on both on possible origins of life and on the wonderful hydrocarbons that have been found out there in the universe.

Sources

Some of these resources may be behind a paywall. Consult your friendly neighborhood librarian for help. Or in the case of research papers, it never hurts to email the author, they may just send you a copy!

Astrobiology: The Study Of The Living Universe by Christopher F. Chyba and Kevin P. Hand. Annu. Rev. Astron. Astrophys. 2005

Astrochemistry: From Astronomy to Astrobiology by Andrew M. Shaw

Beloved Wikipedia.

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Science for SciFi: Peer Review

When a research project reaches completion, the investigators often write up their results in a peer-reviewed journal. Once the investigators decide what journal is most appropriate for their research, they submit their paper, if the editor of the journal decides that the research has merit and is a good fit for the journal, they begin the peer review process.

For many scientists, the peer review process can be stressful and drawn out, sometimes for all parties involved. But the peer review process, despite its faults, is vital to ensuring that honest, quality research gets published.

It’s also likely to be a major source of stress for the scientists in your novel.

There are A LOT of memes about Reviewer 2 out there. Source

Article Anatomy

Each publisher and journal will have its own formatting guidelines. These are the essential bits. Sometimes results and discussion will be a single section and not separate.

Abstract – in science we pack the conclusions into the headline. Abstracts vary in length but are normally about a paragraph. An abstract’s job is to convince someone to read the entire article and to help put what follows into context. Writing an abstract is hard, in just a few sentences you need to explain why the research matters, how it was done, and what conclusions were made.

Introduction – this is (for me) the most fun part of the article to write. The introduction explains the basic principles of an article. An introduction should explain the motivations behind the research and what gap the research aims to fill.

Experimental/Materials and Methods – every journal puts this section in a different place within the article. For someone interested in learning the impact of the research this section is fairly boring, for someone who wants to judge how reliable the data is or replicate certain techniques, this section is essential. Experimental contains a list of what tools and materials were used, who manufactured them, and how they were prepared.

Results- this section explains the collected data in excruciating detail. The data is often supplemented by a variety of graphs and other diagrams.

Discussion – here is where the authors get to explain what the data means. This section is filled with explanation and interpretation.

Conclusion – these are short. Almost as short as the abstract. A conclusion should be short and sweet.

References – any claim that is not common knowledge for the audience or data gained from the research needs to be cited. This might include established experimental techniques, general background information, mathematical formulas, computer code, and so on.

How To Read An Article

How you read an article will depend on what you are trying to get from it. If you are trying to discern the salient points you will probably read the abstract to decide if you care about it. Then maybe the introduction, then the discussion and conclusion.

If you want to explain how the authors reached those conclusions you will spend a lot of time reading the experimental and results sections. You will want to know what they did, understand why, and try and see where the project’s weak points are. This can take a good deal of time and may require multiple readings of a single article.

If you want to know the current state of the field, then a single research article just won’t do. You might find many other sources from the reference list at the end of the article, but you’ll quickly find yourself falling down a rabbit hole. If you are new to a field, you will want to find a review article. A review article is meant to summarize the current state of a given field or subfield and will highlight that field’s important developments. These articles may have hundreds of references.

The Review Process

Once the authors submit a paper, the first thing the editor does is decide whether the article is suitable for their publication. Basically, does it fit the focus of the publication and does it have a large enough impact? Some journals are “high-impact” and some are not. But that is a discussion for another day.

If the paper makes it past this stage the article is sent to a set of reviewers. These reviewers are chosen because they are experts in the field. They are the authors’ “peers” and are likely to have the knowledge needed to evaluate the quality of the research.

These experts comment on the experiments, the data, and may suggest changes that need to be made before the paper is ready for publication. This is where many of the Reviewer 2 memes originate. Authors may often feel that a reviewer’s comments are unreasonable, or that they are trying to manipulate the authors for their own benefit. The good news here is that authors can respond to reviewer comments, and if they can convince the editor that the comments have been addressed then the article can be published.

The key thing to remember is that just because an article has gone through peer review does not mean that it is free of mistakes. A research article is the result of the best possible measurements and analyses that were possible at the time. Peer review means that a small group of experts has decided that the research has merit and that it is free of major flaws.

This doesn’t mean that there are no mistakes, that there is not a larger picture, or that better analysis or measurements won’t be done in the future. A single research paper tells just one small part of a larger journey of discovery.

Emotional Costs

The impact of one single paper is likely to be minuscule, but to the authors, it might well be everything. PI’s (principal investigators) are often established, professors. The other authors, however, are likely students. These students spend years working on a project that might result in just a handful of papers. For these students, the process can be very draining. No matter how “small” the project may be in the grand scheme of things, it has, by the time of publication, been a major part of their life.

For many in academia, publishing is everything. Publishing is how graduate students build a resume. And it’s how many professors achieve tenure. Research activity is frequently measured in publications and grants.

Scenarios

There are a lot of ways to write a scientist’s motivations. But based on what we have just talked about above I will provide a few examples. The examples in this list are for creative purposes only. These are WRITING PROMPTS, not recommendations or endorsements.

  • After years of “publish or perish” the character sees their self-worth only in terms of publications. They frequently overwork themselves and lose sleep in order to make progress.
  • Eager to increase their number of publications, the character divides their research into smaller and smaller chunks to get more papers out. This practice is sometimes called “salami slicing.” It’s frowned upon, but they hope that most observers will only see the publication count and not look much deeper.
  • Desperate to publish in a high-profile journal, the character begins to falsify or omit data. After getting away with it multiple times they think they are safe. Then, several years later, they are found out and their career crumbles around them.
  • The rat race of academia is too much. Fed up with the constant publish or perish mentality, the character decides to take a post at a teaching-focused institution. They publish a paper every few years, but what they really care about are the lives of the students they help shape.

Further Reading

I don’t have any book recomendations about the peer review process. However, peer review and publishing play big roles in the lives of scientists. So here are a couple books where you can learn about the history of science and the people who do it.

Science for SciFi: Poisons

This might seem like a bit of a repeat. After all, we just learned about a few natural weapons, right? Sort of. I talked a bit about how snake venom works, but I think it’s worth our time to learn a bit about toxicology. How do poisons work? How are they administered? Can toxicity be quantified? We’ll get to those answers in a minute. But before we start, let’s get two disclaimers out of the way. First, I am not a doctor and nothing you read here should be considered medical advice. Second, some fields distinguish between toxins and poisons. For the sake of simplicity, I will be using them interchangeably.

How do poisons work? Like we saw with snake venom, poisons work by interfering with the natural processes that happen constantly in your body to keep you alive. If you think about it we are really just a leather sack filled with water and chemical reactions. If anything interferes with those systems then we’re in for a bad time.

Measuring Toxicity

Death is in the dosage. Molecules that we need to sustain life can be toxic if we have too much, and molecules known to cause death might not hurt us at all if we have too little. Determining the amount and duration of exposure that results in toxicity can be tricky, but it’s an important consideration.

Two important considerations are acute versus chronic toxicity. Does the poison kill you immediately (acute), or over time with repeated exposure (chronic)? One measure of toxicity is LD50, often denoted in terms of milligrams per kilogram, which is defined as the median dose that kills 50% of the test population. Chronic exposure is something that workers in many industries need to worry about, but the assassins in your crime novel will be more concerned with acute exposure.

But measuring toxicity can be difficult. After all, it’s hard to find willing human subjects. The easiest way to test potential toxins is to see what they do to cells in a petri dish (in vitro). These experiments can reveal a lot, like the mechanism of toxicity (eg. does it block cell receptors or bind to DNA?) but cells in isolation are a poor model for living systems. Sure, maybe a chemical is toxic to liver cells, but if it never leaves the lungs after being inhaled then its effect may be limited. Large multicellular organisms are more than just individual cells, they are complex systems comprised of many cells with many functions. Toxins may then target a specific organ or grouping or organs depending on how the body processes them.

The best way to test toxicity is to use live animal models, but for obvious reasons, not everyone has the time, resources, or inclination to perform those tests.

How Bad Are Heavy Metals?

Mercury and lead are often thought of as extremely toxic, and for good reason, there are a great deal of environmental and health risks that arise from heavy metal pollution. However, just because something contains a heavy metal does not automatically make it dangerous.

The properties of metallic compounds vary greatly depending on their structure, makeup, and reactivity. For example, heavy metal chlorides may be toxic, but heavy metal oxides may be considerably less so.

Water solubility is a big factor here. If a compound cannot dissolve in water it’s going to have a hard time reaching target systems in the human body where it can do the most damage. But factors such as pH and any reactions the metals might undergo once inside the body can also play a role.

Predicting Toxicity

By now it should be clear that toxicity is hard to predict. It’s not just a matter of what a molecule contains, but what reactions that molecule undergoes inside the body which determines how dangerous it is and what kinds of damage it inflicts.

This is a problem for researchers because not all of the chemicals found within a lab will have been fully studied in terms of toxicity. Because of this, it’s easier to assume everything is dangerous and behave accordingly. That said, there are a few things that can be done to predict a molecule’s hazardous effects.

After a few years in the field, most chemists can intuit the reactivity of molecules based on their structure.

  1. Reactions that occur once released into the environment.
  2. Reactions that occur within biological systems.

For these reasons, predicting toxicity is not as straightforward as one might think, although knowledge of structure and reactivity can give us some clues. There have even been attempts to take known reactivity data, feed it into computers, and generate toxicity predictions. These efforts are unfortunately hampered by a general lack of data in many cases and the number of environmental and chemical variables that need to be considered. Even so, progress in this area is being made.

Famous Toxins

Arsenic – a poison that was favored by Agatha Christie, rat catchers, and stylists alike. Arsenic and arsenic-containing compounds have found many uses over the years as rat poisons, pigments, medicines, and more. Because of these many uses arsenic was once easy to come by and could be bought at many pharmacies. The really dangerous form of arsenic is arsenic oxides. Once inside the body, it disrupts the production of ATP, the molecule that our bodies use for fuel. Arsenic (III) oxides are similar in structure to the phosphates that our bodies use to make ATP and so our bodies try to use them instead. Without a regular supply of energy, cell death soon follows.

Capsaicin – do you really need to know why peppers feel hot on our tongues? Do you care? Maybe peppers won’t drop you dead, but the mechanism is fascinating and very useful to science fiction authors. Capsaicin targets neurons, specifically the vanilloid receptor. In practice, they cause the same sensation as heat. So they hurt, but they could hurt more if controlled by a mad scientist. This is actually my favorite toxin here, because in real life it is relatively harmless, but could be used by a writer in a lot of interesting ways. An alien plant for example, could have a much nastier variety of capsaicin for explorers to stumble upon.

Cyanide-cyanide is a classic. No spy would be caught dead without their cyanide capsule. Like arsenic, cyanide disrupts the production of ATP. In this case, however, it functions as an inhibitor that prevents the enzyme cytochrome c oxidase from doing its part in the ATP cycle. It should be noted, that in this case when we say cyanide we actually mean hydrogen cyanide (HCN). Cyano groups (CN) are common in many areas of chemistry, and hydrogen cyanide has many industrial uses.

Sarin – famous as a chemical warfare agent and a neurotoxin. Sarin acts quickly and can strike you dead in under ten minutes. Sarin is not too different from some of the snake venom we looked at a while back. Like our example there, Sarin works by inhibiting signals sent by nerve cells, but the mechanism is different. The key to sarin’s effectiveness is the neurotransmitter acetylcholine. Sarin permanently binds to receptors and prevents muscle cells from correctly interpreting the acetylcholine signal. The victim’s muscles are then unable to process acetylcholine, hindering their movement, and the victim dies from asphyxiation soon after. Sarin is an organophosphorus chemical that evaporates quickly and is incredibly deadly.

Narrative Uses

Agatha Christie was famous for using accurate portrayals of real poisons in her mystery novels, so much so that an entire book was written about it. By doing this she was able to give her readers the chance to deduce the murderer and the means of murder before she revealed it. The clues were all there for anyone who wanted to puzzle it out.

Whatsmore, knowing what a poison is and what its other uses help to build more plausibility into your story. A worker at a chemical plant might have ample access to hydrogen cyanide, just like a pharmacist in Victorian England would have no trouble sourcing arsenic on the down-low. And of course, for you writers of science fiction, knowing about the mechanisms and effects of real-world poisons allow you to ground your fictional toxins in real science.

Sources

A Is For Arsenic: The Poisons of Agatha Christie. Kathryn Harkup.

Measurement and Estimation of Electrophilic Reactivity for Predictive Toxicology. Johannes A. H. Schwobel et al. Chemical Reviews. American Chemical Society. 2011.

Toxicity of Metal Compounds: Knowledge and Myths. Ksenia S. Egorova and Valentine P. Ananikov. Organometallics. American Chemical Society. 2017.

Science for SciFi: Jargon

a man doing an experiment

Photo by Artem Podrez on Pexels.com

Writers want their smart characters to sound smart. Making a character sound smart sounds hard. But really it just requires a surface-level understanding of the topics and an understanding of keywords.

As a scientist (a chemist) and a writer, I understand this challenge well. So I thought I would help by explaining some basic concepts, keywords, and tools used by scientists. This will be the first in a series of posts highlighting interesting parts of science (mainly chemistry) for writers looking to beef up their technobabble.

My own experience and knowledge of chemistry has biased much of this. My fellow scientists who are reading this and feel their favorite topics have been ignored can resolve this grievance by submitting a guest post or leaving a comment.

The “Three” Branches of Science

There are three basic branches of science, but each of them has many subfields and specialties each with it’s own quirks, norms, and standards. Do not mistake these fields as exclusive. Each field may have it’s own focus but in truth the are better at denoting specialties than limits. The lines that separate these fields are becoming blurrier as time goes on and science becomes increasingly interdisciplinary.

Physics – the “most fundamental science” according to Wikipedia. Physics aims to study force, energy, and motion to understand the fundamental laws of the universe.

Chemistry – the “central science.” Chemistry fills a space between physics and biology. Sometimes it is hard to determine where one begins and the other ends. In general, chemistry is concerned with reactions between different chemicals, or analysis of chemicals and their behaviors.

Biology – this field is concerned with the study of living things. Many think of counting fruit flies and dissecting frogs when they think of biology. Much of modern biology shares techniques with biochemistry as scientists have tried to pull apart the secrets of smaller and smaller systems.

Common Vocabulary

Accurate – often confused with precise. To say that something is accurate assumes that there is a “true” value.

Aliquot – a very specific portion taken from a larger sample of liquid sample.

Amino Acids – amino acids are the building blocks of proteins. There are twenty common amino acids and all share some common structural features.

Atoms – atoms consist of a nucleus containing protons and neutrons, and are surrounded by a collection of “orbitals” where the atom’s electrons are found. An atom is composed primarily of empty space.

Atomic Orbitals – regions of space around an atom where an electron is likely to be. Orbitals that farther away from the nucleus contain higher energy electrons.

Bacteria – ubiquitous and mostly harmless microorganisms. Normally we only care about bacteria when we are sick. Bacteria inside our bodies perform many vital functions that are not completely understood.

microscopic shot of a virus
Photo by CDC on Pexels.com

Deoxyribonucleic Acid – nature’s data storage. DNA tells cells how to build the proteins that keep them functioning.

Elements – an element is a pure substance that contains only one type of atom (not counting isotopes). Elements can now be created artificially. Many of these are unstable and decay quickly, but some researchers have speculated about a potential “island of stability” hiding among the undiscovered high-mass artificial elements.

Evolution – the theory of evolution is a theory, as far too many would like to say. You can read more about that later. But it’s worth remembered that evolution is a fact. If you can’t wait a few million years you can watch it happen in a petri dish. The Theory of Evolution is simply out best explanation of how it works. Another vital thing to remember is that evolution has no pre-determined direction. “Good enough” is enough for nature.

Functional Groups – a segment of a molecule that determines is properties in a reaction. Examples of functional groups include hydroxyl groups, carbonyls, and much more.

Hypothesis – a hypothesis is an educated guess. A scientist takes known information and uses this information to predict what will happen in their experiments.

Inorganic Molecules – defined simply as “not organic,” inorganic molecules can contain both metals and non-metals.

Ions – ions are atoms that have lost or gained electrons and have a positive or negative charge as a result. Paired positive and negative ions form ionic salts.

Isotopes – isotopes are rarer forms of elements that differ in the number of neutrons contained in their nucleus. Natural samples contain a mix of isotopes in different rations depending on purity. Isotopes will vary in atomic mass and stability. These properties make isotopes useful in many applications.

Law – a law describes a known truth about the universe. Theories explain how laws work, laws do not change when a new theory is devised.

Light – both a wave and a particle. Light is a form of electromagnetic radiation. Light interacts with matter in a myriad of interesting ways. Scientists often take advantage of these interactions to study properties of matter that are invisible to the naked eye.

Molecules – molecules are built from atoms. Most things we interact with are some kind of molecule. Bonds within molecules are the result of interactions between electrons and atomic orbitals.

crop chemist holding in hands molecule model
Photo by RF._.studio on Pexels.com

Organic Molecules – the components of gasoline are organic. Organic molecules make up all living things on earth and many dead or inert things as well. Carbon and hydrogen are the primary elements that make up organic molecules.

Peer Review – When a scientists completes a project they write up the results and submit it to a relevant journal in their field. The editor at that journal decides whether the topic is relevant to their publication. If it is, they send the article to reviewers, who are normally other experts in the field. These reviewers look at the article, comment on its merit, and specify what in the article needs to be changed or corrected. An article might go through multiple rounds of corrections before the reviewers decide it is worthy of publication.

Precise – often confused with accurate. Precision is about consistency. Repeated measurements of similar value are said to be precise. We can’t always expect to be accurate, so we aim to be precise instead.

Precipitate – a precipitate is a solid that forms out of a solution.

Proteins – these are how living cells do things. Proteins serve as structural elements, transport molecules, catalysts, and many other things.

Polymers – large chains of molecules constructed from smaller subunits called monomers. Polymers have many useful properties. Kevlar, nylon, spider silk, cellulose, and all plastics are polymers.

Redox Reactions – redox reactions are a huge part of chemistry and biology. The word redox comes from the two related reactions, reduction and oxidation, that are part of every redox system. A useful mnemonic is LEO the lion says GER. Lose Electrons = Oxidation. Gain Electrons = Reduction.

Ribonucleic Acid – DNA’s less popular cousin. RNA carries out several functions inside of a cell. For example, mRNA carries instructions from the nucleus to the ribosome.

Solutions – solutions are everywhere. Solutions have two parts; the solute and the solvent. The solute is a solid that dissolves into a liquid, the solvent. A good rule of thumb when making solutions is that like dissolves like. Polar compounds dissolve in polar solvents, nonpolar compounds dissolve in nonpolar solvents.

Theory – these explain how a particular phenomenon works and why.

Viruses – bits of DNA or RNA bundled up in a shell of proteins and sometimes lipids. Viruses can only survive for a short time outside of a host and reproduce by hijacking the machinery inside of host cells to make more of themselves.

Qualitative – qualitative measurements are somewhat vague. They care about quantities like bigger, smaller, lesser, greater, and so on.

Quantitative – quantitative measurements are exact. They yield a specific number and should have all kinds of statistical analysis to go alongside them.

Quantum – science fiction writers frequently abuse this word. Which is understandable, many trained and experience scientists struggle to grapple with quantum physics because of how unintuitive it is. At this scale the classical physics described by Newton is no longer adequate to model what we observe. So we have a separate branch of physics called quantum physics to describe the behavior of particles on the subatomic scale. Quantum physics is based on probabilities and energy. We can’t nail down the precise location of an electron, but we can determine where it is most likely to be.

Common Laboratory Tools

Balances – many people will recognize these as scales. Many classrooms still used old fashioned balances not unlike the scales found in a doctor’s office. Modern laboratory balances are electronic and can measure mass with a high degree of accuracy.

Dewar – a vacuum insulated container that can be filled with liquid nitrogen, dry ice, or ice water. A dewar is useful for a keeping a sample cold for extended periods.

Gloves – there are two reasons to wear gloves. To protect the scientist from the sample, or to protect the sample from the scientist. The same properties that make many chemicals useful also make them dangerous to human life. Just like many bacteria and viruses that are of interest to scientists are also dangerous. In other cases it is the scientist who could damage the sample. Humans are full of DNA, proteins, and all sorts of other things that could contaminate biological and forensic samples. Gloves are an important part of this. Another important thing to remember about gloves is that the material matters. Nitrile gloves are probably the most common but not all chemicals are compatible with nitrile. Some chemicals may breakdown nitrile or soak right through. Gloves made of other materials are available for those instances.

crop faceless person in outerwear putting on latex gloves
Photo by Laura James on Pexels.com

Glove Boxes – for samples that must be rigorously protected from oxygen, or for samples that may be dangerous to the user, glove boxes are the best option. Glove boxes are exactly what the sound like. A large box, with a glass window and a pair of large rubber gloves. The inside of a glove box is filled with an inert gas like argon or nitrogen.

Heating Mantle – chemists use heating mantles to drive chemical reactions by converting electricity into heat. Heating mantles are controlled by a variac that regulates the supplied voltage. Some heating mantles have a built-in variac, but in most cases the variac is a separate component. Heating mantles are often placed on top of magnetic stir plates.

Hot Plates/Stir Plates – hot plates are another option for heating solutions and materials in lab. Many have a built-in magnetic stirring function that can make a magnetic stir bar inside the reaction vessel spin.

Mortar and Pestle – a frequent component of imagined alchemy labs. Mortar’s and pestles remain useful tools in chemistry and biology labs.

Pipettes – pipettes transfer small volumes of liquids. Some pipettes are carefully calibrated, others are little more than fancy eye droppers.

crop chemist using modern equipment during work process
I’m not sure what they’re trying to do in this photo. I have no idea why anyone would clamp a volumetric flask like that. Or why they would use an open flame instead of a hot plate (flammable vapors make an open flame dangerous in many labs). Still, it’s a good illustration of a pasteur pipette being used to add approximate amounts of a certain chemical.

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Spatulas – spatulas are used to move solid chemicals from one place to the other. For example, from the bottle to a balance or from a weigh boat to a reaction flask. Metal spatulas will be common to most undergraduate, but some labs use disposable plastic spatulas.

Syringes – syringes are incredible useful. Biologists may find many uses for syringes in drawing blood or injecting drugs. Syringes are used to work on air free reactions. Syringes are fantastic for piercing septums and adding or subtracting aliquots with minimal interference from surrounding oxygen.

Common Laboratory Instruments and Techniques

Some instruments are available from commercial sources for thousands or millions of dollars. Others are so specific that they need to be custom built by the user.

Centrifugation – centrifuges separate sample components by density. The centrifugal force causes high density sample components to move outward and form layers.

crop unrecognizable cosmetologist taking test tube out of centrifuge for plasma in modern clinic
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Chromatography – chromatography separates sample components. All chromatography involves a mobile phase and a stationary phase. The mobile phase carries the sample through the stationary phase. As the sample interacts with the solid phase it becomes separated into its components. Many techniques pair chromatography with another analytical technique such a spectroscopy or mass spectrometry.

Electrophoresis – electrophoresis describes the movement of charged particles in an electric field. Multiple separation techniques use electrophoresis to separate sample components such as gel electrophoresis or capillary electrophoresis.

Fluorescence Spectroscopy – some molecules absorb light at one wavelength and emit light at another. Fluorescence is useful in many instances and especially in biology and biochemistry. The strong signal given by fluorescence makes it easy to distinguish from background noise. This is its main advantage over absorbance spectroscopy.

Infrared Spectroscopy (IR) -heat is transmitted through infrared waves. When those waves hit a molecule, parts of that molecule vibrate in characteristic ways. These vibrations are like finger prints for different functional groups.

Nuclear Magnetic Resonance Spectroscopy (NMR) – probably one of the most useful instruments in modern chemistry. Nuclear Magnetic Resonance takes advantage of the “spin” that is an inherent property of subatomic molecules like protons and electrons. Basically they behave like tiny magnets. An individual spin has a value of either +1 or -1 and when opposite spins are paired these spins cancel each other. Certain isotopes of common elements have an odd number of subatomic particles in their nucleus resulting in a non-zero spin. NMR works by placing a sample inside of a magnetic field. The unpaired spins then align with the field and the instrument hits the sample with radio waves of a specific frequency. The unpaired spins then flip as they absorb the energy from the radio waves and release energy as they return to their original orientation. The environment surrounding each unpaired spin affects the signal they emit, allowing us to determine the structure of molecules. Proton and Carbon 13 NMR are most common, but isotopes of Oxygen, Fluorine, Phosphorus, and more can also be targeted. Special, expensive solvents have to be used for liquid samples to avoid interferance. The same technology is also used in MRI except in this case the density of spins is used rather than the individual behavior of those spins.

person holding silver round coins
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Mass Spectrometry (MS) – another incredibly useful instrument in modern science. Mass spectrometry begins by injecting a sample, ionizing it, and shooting it at a charged plate. This results in peaks that show us the mass-to-charge ratio. Mass spectrometry can do a lot. So much that mass spectrometry research almost constitutes its own subfield, but it is useful to all other niches of chemistry.

Ultraviolent/Visible Spectroscopy (UV/Vis) – UV/Vis instruments are used to study a sample’s interactions with light in the visible and ultraviolet range. There are two basic types of readings we can get from this: absorbance and transmission. Absorbance is how much light the sample absorbs, transmission is how much light passes through the sample. Accurate readings depend on knowing the emission profile of the light source. Basic instruments assume that this profile is constant, more sophisticated instruments take constant readings of the light source. Interference in these experiments may come from fluorescence in the sample or form surrounding light sources.

X-Ray Spectroscopy – of all the electromagnetic waves X-Rays contain the most energy and are the most destructive. These high energy rays frequently ignore anything outside the nucleus. Various forms of X-Ray spectroscopy are used to determine the structures of solid crystals and identifying the elements and isotopes in a sample.