The Science of Aging and its Fictional Cures

Aging

Author’s note: This article was originally published by invitation in Dan Koboldt’s Science in Sci-fi blog series. See the original article here. If you are interested in more Science in Sci-fi, check out Putting the Science in Fiction for expert advice on writing Sci-fi and Fantasy with authenticity. It will be published in October 2018 by Writers Digest, with a foreword written by bestselling author Chuck Wendig. You can pre-order on Amazon, just click on the cover image to be redirected. I will have an article published in the book.

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The Science of Aging and its Fictional Cures

All things age. For non-biological objects, it is a matter of entropy and oxidation (see “Aging Properties” by Gwen C. Katz in Putting the Science in Fiction). While life is not immune to these effects, it has the ability to replenish itself, repair damage, and theoretically exist indefinitely. So why don’t we live forever? This article will explore the science of biological aging and debunk some of its misconceptions in fiction.

 

Myth: Death by Old Age

“So-and-so died from old age.” We’ve all said it or heard it before. But can age really kill you?

Ultimately, aging does not kill you, but makes you more vulnerable to other things that will. As time goes on, our physiological integrity weakens and cells no longer act like they should. Muscles weaken, metabolism slows, and we all become a bit more sedentary, leaving us at risk for accidents, diabetes, metabolic syndrome, and coronary artery disease. Similarly, DNA repair slackens and increases the risk of cancer, the immune system becomes erratic and can lead to autoimmune diseases, and the brain loses it edge and degenerates. All together, the chance that something will kill you every year is over 1000x more likely in the elderly than in children.

How to get it right:

Here are some of the most common causes of death:

Heart disease

Cancer

Stroke

Lung diseases and infections

Accidents

Diabetes

Alzheimer’s

Kidney disease

For the most part, the incidence of all of these causes of death increases with age. In other words, age is never the cause of death, but age-related diseases are. Similarly, “death by natural causes” is commonly used to describe the death of an elderly individual, since these causes are common enough to be considered natural.

 

Myth: There Exists Such a Thing as a Life-Force

There persists a notion that life is some ethereal force that courses through us, able to be sucked away by the first succubus/incubus that lures us in. Aging, therefore, would be the waning of such a life-force.

As far as we know, there is no ethereal energy that perfuses all life and makes it work. In fact, life can be manufactured by going online, copying the genetic sequence of a simple organism, synthesizing the DNA in a machine, and injecting it into an empty husk of a cell. This artificial “life” will then proceed to live on its own as shown by an experiment performed in 2010 by Craig Venter.

How to get it right:

All life has a few things in common, though there are exceptions to the rule. The standard definition of life is an entity that can grow, reproduce, undergo metabolic processes, and sense and interact with the environment. From this definition, metabolism is about the only thing that can be considered a life-force that can be given or taken away.

There is some truth to the concept though, as mitochondria, the energy producing organelles in most of our cells, do lose some of their efficiency as we age, and are implicated in many age-related diseases. Similarly, there do appear to be factors circulating through our body that affect how we age, and these can even be transferred from one person to another. Parabiosis is an experiment wherein two animals are surgically connected, allowing them to share blood. The older of the two animals will show signs of improved cognitive performance, muscle development, heart health, cellular regeneration, and properties that typically deteriorate with age.

The circulating factors thought to mediate this effect are certain inflammatory molecules (cytokines), small packets of intracellular materials (exosomes), some mitochondrial proteins, and many others. Interestingly, some of these are the same factors that promote systemic health following exercise. So unless you plan to surgically attach yourself to your much younger friend, or are currently a succubus/incubus, exercise truly is the best medicine.

 

Myth: The Elixir of Life and other instant cure-alls

Fiction often portrays the cure of aging as an easy fix, often restoring youthful vitality and vigor over the course of just a few minutes. Such an elixir smooths wrinkled skin, increases muscle mass, darkens silver-white hair, and eliminates all ailments associated with age. If only it were that simple.

Many researchers agree that aging is the result of mutations and other damage that accumulate over time, causing cancer, affecting metabolism, protein turnover, the immune system, the endocrine system, etc. A cure to aging would need to reverse all of this damage. Among other things, this would require replacing the lost connective tissue in the skin and removing it from areas where it has been produced in excess, like the muscle. It would need to revive cells that have already died, and kill cells like cancer. Additionally, the cure would need to remove lipid plaques from the vasculature, amyloid plaques from the brain, and fix every type of damage down to individual proteins and DNA mutation. And by most depictions, all of this would occur over the course of a few seconds to minutes. While this may look visually impressive, it would be impossible. The changes that occur with age are just too numerous and widespread to be reversed.

A fictional remedy like small nanomachines would have to constantly change shape, be physically capable of reaching every crevasse of every protein and condensed DNA strand, retain the information of what to fix and how, and somehow produce and store enough energy to complete the task. Even if it could somehow do all these things, fixing the accumulated damage would not be instantaneous, nor would it be visually apparent for at least a day or two. Similarly, gene editing never shows immediate effects, whether by taking years off your appearance or, if so designed, transforming you into a werewolf.

How to get it right:

Fortunately, there are some drugs and lifestyle changes being explored that have been shown to increase lifespan in mice and other mammals, though the effect is relatively mild. Some of these longevity enhancers have negative side effects, however, like testicular atrophy in the case of Rapamycin. Similarly, caloric restriction doesn’t sound like something I would do voluntarily. Even taking such measures, an indefinite extension of our lifespan may not be possible without something to extend our telomeres, the condensed DNA at the end of our chromosomes that gets shorter with each cell division.

Of course, your fictional characters might choose to skip over the cure, and abandon their aging bodies all together for something far more durable. They have merged them, body and mind, with machines. For more info, see Edward Ashton’s post on Immortality in Science Fiction.

 

Myth: Agelessness and the Fountain of Youth

Since reversing aging seems unlikely, the only other option would be to make your character ageless, resistant to the wear and tear of time. However, like wizards and elves, the ageless being is completely fictional.

The most common source of damage within the cell is the act of living itself. While metabolizing our food and consuming the oxygen we breathe, the mitochondria occasionally produces a small amount of oxidants, which then oxidize proteins, DNA, and lipids. DNA polymerase, which is responsible for copying our DNA during cell division, can slip or make a base-pair mismatch. Our immune system, which functions primarily to rid us of invading micro-organisms, can get overzealous and damage other cells caught in the crossfire.

Also, let’s not forget that life is just complex chemistry, and sometimes damaging chemical reactions will occur at a low frequency that are impossible to prevent, like the hydrolysis of DNA. Another major cause of the accumulating damage is the environment. Background radiation, toxins from our food or water, and the aforementioned microorganisms can interfere with all manner of biological processes and inflict direct damage. Eventually DNA damage accumulates, leading to cellular dysfunction, and ultimately death. To be ageless, one would have to resist all of this damage.

How to get it right:

Not all beings are created equal, however, and many creatures that have found a way to subvert the effect of time.

Take the “immortal jellyfish” for example. It is said to live indefinitely by reverting back to an immature polyp state. Unfortunately, humans are quite a bit more complex than a jellyfish. Such a state of immortality would be like taking the DNA from one of your cells and cloning yourself. Your clone would have none of your memories and be a distinct organism. Another creature, the naked mole rat, has extraordinary DNA repair capabilities and connective tissue factors. It looks nearly identical at year one as it does at an impressive 30 years old, which is to say it looks rather hideous all its life.

The Icelandic clam, the Greenland shark, and some other sea-dwellers have been known to live as long as 500 years, partly due to its resistance to oxidative damage. Somehow, I don’t think their natural environments would be compatible for us, but the secret to their longevity may one day be translated to humanity.

If a means to become ageless is developed during your lifetime, chances are you won’t be able to use it. Your unborn children, however, might be more fortunate. The most likely method will be to modify our progeny’s’ genetic code to enhance cellular repair, telomerase activity, antioxidant enzymes, and other processes shown to prolong life in animal models. Only then would human biology have a chance at resisting the ravages of time.

 

Conclusion

Life is complex; so many parts need to come together to keep it functioning, and if one thing falters, so does life end. Gerontology is the study of how those complicated parts of life fail over time. The Somatic DNA damage theory of aging alluded to in this article is just one theory of many. Other theories include antagonistic pleiotropy (i.e. that which makes us strong early in life, makes us weak later), disposable soma theory (i.e. keeping the body young isn’t the best allocation of resources), the replicative senescence theory (i.e. telomere shortening), rate of living theory, other damage accumulation theories, as well as some theories proposing we are programmed to age and die, often for the “overall prosperity of society.” There are still numerous theories of aging which haven’t been conclusively proven or disproven, and until we know the real cause, finding the cure will be all the more difficult.

“If there is one thing a Gerontologists understands, it is complexity,” said Dr. William Hazzard, a renowned gerontologists, at a 2018 aging symposium named in his honor. And while there is currently no cure for aging, there are things we can do in the meantime to slow it down. Dr. Hazzard, an 81-year-old academic who took the three stairs to the podium in one leaping bound, asserts that the best medicine is to “keep moving,” to “keep learning,” and above all, “embrace the totality of the experience.”

 

Until next time, Write Well and Science Hard

The Science of Exobiology

Space rocks

So you want to introduce a new lifeform in your fiction. There are many reasons to do so. A sentient humanoid can provoke your reader’s sympathy and relatability, while a vile, brainless, and flesh-eating slug can put your readers on edge. If done sloppily, however, skeptical readers will find the flaws in such a creature, and that disbelief will undermine any of your attempts to draw them into the story. You can blame biologists for always taking the fun out of your unique imagination, or you can choose to awe them with the many ways you manipulate biology into something terrifying or beautiful. After all, there are millions of weird and wonderful species on our own planet, some far more alien looking than what sci-fi authors have conjured up over the years.

anemone

“Fish and anemone,” picture by Philip Kramer at the Seattle Aquarium

Here are the things you should consider when making a new species:

 

What is life anyway?

To breathe life into your creation, you should first understand what life is. The standard definition of life is an entity that can grow, reproduce, undergo metabolic processes, and sense and interact with the environment. This simplistic definition has led to some interesting debates. A virus for example, can do little to none of these things outside a host cell. Is it a living thing? Crystals too can take in energy and materials from their environment and use it to grow and reproduce. Is a crystal alive? Alien life will also likely defy some of these rules.

So what might life on another planet look like? This field of study is referred to as exobiology and astrobiology.

 

All life is a product of its environment.

Everything about life, down to each protein or strand of DNA, was selected for over the course of millions of years. If an organism died before passing on its genetic material, the next generation would not inherit those characteristics that lead to premature death. This is evolution, and because of it, nearly everything about you has a purpose and function.

True, there are some things that appear to have no function except to give scientists headaches. These things exist because they can, or because they did not provide an evolutionary disadvantage. For example, many of the glycoproteins coating each of our red blood cells have no apparent function. Others, like the Duffy antigen, are used by the malaria parasite to infect cells. As a result, many individuals whose ancestors were from malaria-prone regions do not express this antigen. The simple rule is this: evolution will select against adaptations that negatively affect a species’ chances of survival and procreation, but any adaptations that improve those chances, or don’t change them at all, will persist.

On Earth alone, evolution progressed down millions of branches depending on environmental pressures. Many of those branches ended when these evolutionary experiments failed or the creature was overpowered by another creature attempting to take over the same ecological niche. As humans, we adapted our opposable thumbs from grasping tree limbs to avoid predators on the ground and reach food high in the canopy. We became bipedal to facilitate running and giving us a height advantage to spot both predators and prey when traveling across the ground. When intelligence improved our ability to hunt and forage, we dedicated much more room and energy to developing it. For other animals, they took to the air, or stayed in the water, and evolved talons, teeth, and scales to defend themselves. Any change to the fictional environment would make your creatures change accordingly. If the atmosphere was just a little thicker, for example, like the one on Venus, instead of birds with wings, you might have puffer-fish like creatures that fill an air-bladder with hydrogen or oxygen to float around. If your creature lives in dark caves like Astyanax mexicanus, a Mexican cave fish, they will probably have no eyes, or at least not ones that function.

 

Familiar or strange?

Going out of your way to creating an entirely original and strange lifeform may not be necessary. In fact, some scientists think life can only come in a finite number of forms. So it is possible that alien lifeforms share characteristics with us or other life on our planet. Darwin’s Aliens, is a new theory suggesting that there are only a handful of ways biology can evolve to deal with its surroundings. Yes, even biology is beholden to the laws of physics. Take the eyes as an example; there are only a few ways a creature might focus light from its environment onto a cluster of light sensitive cells. Evidence suggests that eyes evolved independently on dozens of evolutionary branches on Earth into something that looks and operates very similarly. The number and placement of those eyes on the head are also no coincidence, allowing a large range of vision without taking up too much space and energy in the brain to process that information.

Just because alien life might look familiar, doesn’t mean it can’t be strange. You can still be creative with your alien. In fact, it is very unlikely aliens will look too similar or identical to life on Earth. Since we exist because of a series of random genetic mutations and environmental coincidences (like ice ages and the particular tilt of our planet caused by the moon), it is very unlikely a species from another planet will have experienced the same evolutionary history.

Designing your lifeform.

The simplest unit of life as we know it is the cell. Alien life will most likely be composed of cells too, as it is the natural progression of simple to complex life, and allows each unit to carry the genetic information required for it to grow and replicate. Your alien can be a single cell, or a complex lifeform composed of two or more of these units working together for mutual survival. This partnership also allows some cells to specialize in certain tasks (defense, digestion, locomotion, etc.) to make tissues and organ systems.

Here are some of the features and organ systems most complex life should have:
Size- No matter the planet, there will be gravity, so your lifeform’s proportions will likely adhere to the square-cube law. This law, while by no means strict, describes most of the complex terrestrial life on Earth. In simple terms, it describes the relationship between volume and surface area of a creature. As a creature grows in size, its surface area does not increase at the same rate as its volume. As a result, larger animals must have thicker limbs to support a greater mass, a circulatory system to deliver nutrients and gasses through its body, and methods to dissipate heat through its lower relative surface area. Increasing an insect to the size of a cow would make its exoskeleton heavy, and its spindly limbs unable to support the mass of its bulbous body. Additionally, it could no longer rely on it tracheoles and hemolymph to diffuse oxygen throughout its body.

bug

“Pillbug,” by Philip Kramer, (edit of picture)

Skin- Often the largest organ in the body, it is the last barrier between living flesh and a harsh environment with no regard for living things. Making a sentient slime the primary host of a hot, water-poor planet like Venus would not only be impractical, but evolutionarily impossible. A type of lizard with scales that reflect infrared and are resistant to sulfuric acid rain, however, would be far more likely. If the planet is cold instead, fat deposits or thick fur will serve as good insulation.

In addition to a physical barrier, the skin can also serve as an optical defense or lure. Lizards, butterflies, encephalapods, and many other creatures disguise themselves with their surroundings, make themselves look menacing, or lure in other creatures by appearing to be harmless.

 

fleattle

“The Fleatle,” by Ian Dowsett

Skeleton and muscles- In some cases, the skeleton can take place of the skin. This is known as an exoskeleton. While it can provide protection from the external world, it is not very deformable, and weighs too much on large creatures. Additionally, such a skeleton would limit growth, and occasional periods of molting would make the creature vulnerable to injury. An internal skeleton provides more joint versatility, structural support, and anchorage for ligaments and tendons. Add muscles, and the creature will be able to move through and manipulate the environment around them. The means of locomotion will vary depending on its evolutionary environment, allowing for wings, fins, tentacles, or feet and hands. The type and position of joints is going to alter the function of the limb. For example, the elbow and knee are terribly weak joints (the fulcrum near the end of lever), meaning it takes a large amount of force to move the limb. Why would evolution do this? While the arms and legs are weak, their length away from the pivot point means they can move at incredible speeds, ideal for running, climbing, and throwing things. By contrast, relatively small muscles in joints used for crushing and raw strength, like the jaw, can allow bite pressures of over a thousand pounds per square inch in the hippopotamus, alligator, and hyena.

Tim's alien

“Gra’Sugra” conceptualized by Tim Kramer, illustrated by Joseph Martin

Brain- The nervous system, a means by which creatures control their limbs and the movement and function of other organs, can be simple or complex. For complex creatures, they come in two major types: centralized and decentralized. A central nervous system, like our brain and spinal cord, control all peripheral communications. A decentralized nervous system, like the octopus, has multiple little brains that can act independently of one another, or coordinate with each other without sacrificing intelligence. If your human explores encounter an alien starship, chances are the alien creature will have a complex nervous system, for how else would they have constructed such advanced technology.

ForC

Centralized nervous system- “ForC” by Ian Dowsett

 

Drude

Decentralized nervous system-“Drude” by Ian Dowsett

 

Metabolism and digestion- Biology is a huge source of entropy, bringing far more chaos into the universe than order. Life gets its energy by breaking existing molecular bonds and using that energy to create new ones. But we break far more bonds than we form. As humans, we must consume dozens of tons of food over the course of our lifetimes just to maintain our relatively unchanged size and shape, and perform comparatively low-energy functions.

The source of molecular energy a lifeform uses can vary. On Earth, most life gets its energy from breaking down simple carbohydrates, fats, or proteins. These in turn were formed by other lifeforms. Chances are the circle of life will come back to plants, who ultimately get their energy from the sun to form carbohydrates. In areas that lack sunlight or are too inhospitable for plant life, ecosystems revolve around other root sources of energy. Deep under the ocean at hydrothermal vents, where temperatures can reach higher than 400 degrees Celsius, the base life form are extremophiles (Archaea) which can use non-organic compounds to synthesize energy in the absence of sunlight. These in turn feed larger crustaceans and nematodes.

Morning Glory

Morning glory pool at Yellowstone. Many colors attributed to extremophiles. Picture by Philip Kramer

It is also possible, that aliens will not find humanity or other forms of life appetizing unless they evolved similarly. We have very specialized enzymes for very specific foods, like glucose (D-glucose, not L-glucose), amino acids (L, not D), and fats. If an alien predator does not utilize these same substrates, we will not taste very good or sit very well with them.

Waste disposal- On that topic, waste disposal is another must for complex organisms. It is impossible to digest, utilize, and recycle 100% of ingested food. At some point, toxins, and metabolic waste will need to be eliminated. Intestine type organs to digest and absorb, a liver to detoxify, and a kidney to filter our liquid waste, are common features of most complex life on Earth. Some creatures, like birds, reptiles, and most fish release both solid and liquid waste and reproduce through a single orifice called the cloaca. The aliens in The Post-Apocalyptic Tourist’s Guide series, have such an orifice, much to the amusement of all the authors in the series.

TPATG alien

Alien from The Post-Apocalyptic Tourist’s Guide series, illustrated by Stephen Lawson. Note: over-emphasized cloaca.

Reproduction- Life is complex, therefore it requires a lot of genetic information to maintain and recreate it. No matter what your alien species, they will have a genetic material (could be DNA, or some silicon-based version of it), and a method of reproduction. It can be an asexual species that creates clone-like copies of themselves like many starfish, or it can reproduce like humans and most other animals with two or more members of the species contributing genetic code.

starfish2“Starfish,” by Philip Kramer, (edit of picture)

Or, like slugs, they can be hermaphroditic, possessing both male and female reproductive organs.

 

slug1

“Seattle slug,” by Philip Kramer (edit of picture)

Circulation and respiration- The need for a way to distribute metabolic substrates and facilitate gaseous exchange is necessary for all large and complex organisms, including plants. The lungs and/or gills would need high surface area to facilitate the transfer of gasses. In smaller creatures, diffusion is sufficient, though rudimentary tracheoles, a heart, and hemolymph are present in many insects. Aside from supporting metabolism, the circulation is an ideal medium to support an internal defense against invading organisms. Most animals have a complex immune system supporting many types of specialized cells. Any alien coming to Earth would not have the adaptive or innate immunity required to repel local microorganisms. We would also have no defense against alien microbes.

Senses- Like locomotion, the senses will be defined by the environmental medium and ecological niche of the creature. Vibrations travel through air far better and faster than they do through a medium with little to no compressibility like stone or water, so many terrestrial creatures will likely have ears. Assuming there is light to see by, aliens will also have a type of eye, though it may see different parts of the spectrum. Tiny hairs, like those on insects, could improve tactile awareness, and receptors for aromatic molecules can provide a sense of smell. Humans have far more than five senses, so there are plenty to choose from to make your aliens as aware or unaware of their surroundings as you want. If, for example, your aliens only see in infrared, your space troops could use a special armor to disguise their heat signature.

Samuel“Samuel,” by Ian Dowsett

Mechanical augmentations- Aliens with a computer driven intelligence or mechanical augmentations are an exception to many of these “rules.” They will need energy, but this can come in many different forms, and they will not need to digest or dispose of waste in the same way. Despite the differences, however, they would have needed an intelligent biological host or a biological predecessor to design them. Seeing as how mechanical lifeforms are far more resilient, they will likely be the first interstellar visitors we encounter.

The tide

“The Tide,” Conceptualized by Tim Kramer, illustrated by Joseph Martin

Conclusion.

Congratulations, you have now made an imaginary lifeform and, ipso facto, you now have imaginary godhood. Don’t let it go to your head. Even a novice biologist will likely be able to undo all your hard work. But you have one thing going for you. Give your creatures all the things required of life, make it beholden to the laws of physics, and a product of its environment, and even those pesky naysayers won’t be able to prove its nonexistence. If you are still having trouble, take a page out our own planet’s ecological history. There are many millions of species with unique features, functions, and evolutionary trees, right here on Earth. With a little bit of research and imagination, we can all be amateur exobiologists.

 

Until next time, write well and science hard.

The science of suspended animation

Stasis2.png

I sold my first non-fiction article!

Back in January, I got in contact with Tony Daniel, the senior editor of Baen books, sent an article proposal, and signed a contract. Around the same time I won the Jim Baen Memorial Short Story award. I think it took him a couple of weeks to realize he was communicating with the same person in the two different email chains. This article was originally going to be posted last month, but he felt it was best not to publish it the same month as my short story “Feldspar.”

Here is the link to the article on the Baen website: “Stasis: The Future of Suspended Animation.”

For this article, I managed to get an interview with Dr. John Bradford, the COO of SpaceWorks, who is pioneering the development of suspended animation techniques with NASA for future human expeditions to Mars.

Here is the full, unedited interview:

Me- “How long could hibernation theoretically be sustained?”

Bradford- “One initial comment that is a bit of semantics, but we like to always clarify. On the term ‘hibernation’: We can’t actually make people hibernate, so prefer terms like “human stasis”, “torpor inducing”, and “metabolic suppression”. Maybe in the distant future through gene therapy/modification, this can be achieved, but right now we are focused on artificially inducing a hibernation-like state via cooling and metabolic suppression. So, we are trying to mimic hibernation, but not achieve it.

We are in the process of evaluating how long we can sustain the low metabolic state. This will ultimately have to be determined through testing, but since we are starting with current practices for Therapeutic Hypothermia, we have a lot of data to evaluate on what is occurring in the body over short 2-4 day periods. Longer periods of up to 14 days has been achieved, but data there becomes much more limited. We also look at animal hibernators as sources of understanding (and inspiration). Bears are a great model since their core temperature doesn’t drop to the extreme conditions most hibernators experience. They can be in torpor for 4-5 month periods. In summary though, we don’t know what the theoretical limit is yet. For our approach, it would not be measured in years. We can benefit a lot in terms of space travel if we can achieve just a few weeks, but ultimately we are looking to achieve months.”

Me- “Are there any plans to test human hibernation in the near future?”

Bradford- “Eventual human testing is on our roadmap and plans. NASA’s NIAC program is not funding us for any medical testing though, only to evaluate if this is possible, identify how we would do this, and quantify the mission impacts if it is feasible (engineering analysis). However, we are getting inquiries from a few investors and looking at non-governmental funding sources to start some specific testing. Note again that we do have medical data from subjects undergoing TH over short periods already, but those were not controlled tests.”

Me- “What is a major medical/engineering hurdle that will have to be overcome before this technology can be implemented?”

Bradford- “I get asked this question a lot and my answer probably changes frequently depending on what aspect I’m currently working on or problem I’m trying to solve. There are certainly challenges, but we are coming up with a variety of solutions or ways to mitigate them, either via a medical approach or engineering it out. The ability to initiate human testing will certainly be a milestone – fortunately I hear from a lot of people that want to volunteer! Transitioning to space-based human testing would be the next big step.

Lastly, I’d say we believe human stasis represents one of the most promising approaches to solving the engineering and medical challenges of long-duration spaceflight. With this technology, a variety of new options can be introduced and applied that address major human spaceflight medical challenges and risk areas such as bone loss, muscle atrophy, increased intracranial pressure, and radiation damage. System-level engineering analysis has indicated significant mass savings for both the habitat and transfer stages. These savings are due to reductions in the pressurized volume, consumables, power, structures, and ancillary systems for the space habitat. This capability is potentially the key enabling technology that will ultimately permit human exploration to Mars and beyond!”

To read the full article, including other interviews, and to learn about the science of suspended animation, click the image below:

 

stasis article

Link to Baen article: http://www.baen.com/stasis

The science of enclosed ecosystems

billy-and-rubin-ecosystem

Earlier today I did a guest post for fellow blogger, writer, and scientist, Dan Koboldt. I came across his blog about a month ago. He and I share the same mission, to promote the use of accurate science in sci-fi. But rather than do all the background research on his own, he wisely seeks out professionals in related fields and asks them to write about scientific misconceptions in sci-fi and how to get it right. Since my own lab work concerns cellular respiration, I offered to write a post for him on enclosed ecosystems, and he generously agreed. You can see the original post by clicking on the graphic below:

ecosystems-and-life-support-in-scifi

Enclosed ecosystem and life-support systems in sci-fi

A Closed Ecological System (CES) is a broad term that encompass any self-sustaining and closed system in which matter does not leave or enter. These artificial habitats can be built in space, underground, or underwater, but no matter where they are, chances are they are closed for a reason. Whether it is an underground bunker in a post-apocalyptic setting, a distant planet in the early stages of colonization, or a spacecraft carrying the last remnants of humanity, the environment outside is not hospitable. To ensure long-term survival, the occupants must maintain a well-balanced air and water system, a continuous food supply, and a reliable source of energy.

So far, no artificial enclosed ecosystem has successfully supported human life for long periods of time. Even the astronauts on the International Space Station get regular supply runs and have to exchange personnel. The largest CES was Biosphere 2, which sustained 8 crew for 2 years; however, they had to resort to some extreme measures to keep oxygen and carbon dioxide levels in normal ranges, and many of the plant, animal, and insect populations died off.

Creating and maintaining a CES is difficult, as many fluctuations or imbalances can cascade into environmental collapse without continuous monitoring and support. Here I will discuss a few of the misconceptions about Enclosed Ecosystems and Life Support systems and suggest ways to get it right in Sci-fi.

Myth: Waste is useless and should be disposed of.

You see this in many sci-fi stories set in space; the airlock door opens and a stream of garbage is ejected into the vacuum. This might be acceptable for short-term missions, where all the supplies needed are carried along, but for an ecosystem intended to last for a long time, being wasteful is not an option. It is a matter of mass balance. In most situations, it won’t be possible to obtain resources from outside the enclosed system, so if your characters are ejecting waste of any kind out the airlock, soon there won’t be anything left. By the same principle, if some waste product cannot be recycled, it will build up and eventually consume all of the precursor materials.

Getting it right

When creating a life-support system for a fictional crew, they must adhere to a strict recycling policy. Most solids, such as plastics and metals or glass, can be melted and recast into any number of shapes. Of greater importance is the conversion of gaseous, liquid, and solid wastes into breathable air, drinkable water, and edible food. Solid organic wastes such as material from dead plants, animals, or their excrement, contain large amounts of nitrites and nitrates, phosphates, and other inorganic compounds that serve as fertilizer for plants.

Having a ‘living soil’ or cultured hydroponic system is also necessary, as bacteria, like those found in the human gut, are great at breaking down complex organic molecules and making them assessable to the roots of plants. So far, there is no easy way to convert waste, carbon dioxide, and water into an edible food source, outside of a biological system, such as a plant. Such plants can be consumed as food, and the cycle is repeated.

Myth: Water evaporates and condenses, but the total amount doesn’t change.

You hear this often in terms of a large environment like the Earth, where water rises from the oceans and falls again as rain, and it is true for the most part. Only a few processes create or break down water, but in a small, highly balanced environment, they can make a huge difference. Water is made and destroyed in biological systems during condensation reactions and hydrolysis reactions, respectively.

But the most significant of these reactions occurs in the mitochondria, the ‘energy’ producing organelle in nearly every cell. In the mitochondria, oxygen receives 4 electrons from the Electron Transport Chain and is reduced to water. Yes, nearly all of the oxygen you absorb through your lungs is converted into water. The reverse happens in plants, where water is hydrolyzed into oxygen during the construction of carbohydrates during photosynthesis.

Getting it right

The balance between animal and plant life on the ship should ensure a stable supply of water, but water can be made and eliminated artificially if there is ever an imbalance. Electrolysis, breaking water into hydrogen and oxygen, can be accomplished with a little electricity. That processed can be reversed by burning hydrogen in the presence of oxygen. A means of storing oxygen and hydrogen or water should be in place to deal with small fluctuations. Humidity and condensation can cause severe damage to electrical systems, especially in zero gravity, where air currents can become stagnant. This also increases the risk of mold. Cold surfaces or specialized air filters can trap the water vapor and return it to storage.

Myth: Plants convert carbon dioxide into oxygen, while animals do the opposite.

Unfortunately, the biochemistry isn’t so simple. Oxygen is not converted into carbon dioxide in animals. As I already mentioned, nearly all of the oxygen you absorb is converted into water. Carbon dioxide is released from the breaking down of metabolites like sugar, proteins, and fats. This takes place in the mitochondria. In plants, oxygen is made when both carbon dioxide and water are converted into carbohydrates like glucose during photosynthesis. This occurs in the chloroplast in plants.

food-water-and-air-cycles

Another misconception is that producing oxygen is all plants do. In reality, plants have mitochondria too, and they consume oxygen and carbohydrates and produce carbon dioxide and water. When the lights are on, plants tend to produce more oxygen than they consume, but without light, they will suck up the oxygen as hungrily as we do.

Getting it right

Even as little as 1% concentrations of carbon dioxide can cause acute health effects such as fatigue and dizziness, but even higher concentrations (7-10%) can lead to unconsciousness, suffocation, and death within hours. To control fluctuations in carbon dioxide, CO2 scrubbers can be used. However, carbon dioxide is an intermediate step in oxygen and carbon cycles, so this artificial means to lower carbon dioxide may cause downstream effects on plant growth and lower oxygen concentration. This occurred accidentally in Biosphere 2 when carbon dioxide was converted into calcium carbonate in exposed concrete.

Materials like metal oxides and activated carbon can be used in CO2 scrubbers and then the carbon dioxide can be released at a later time. Large variations from the normal 21% oxygen is more easily tolerated than variations in carbon dioxide, but long-term exposure to greater or lower concentrations can lead to many acute and chronic health effects. Adjusting the amount of artificial or natural light available for photosynthesis is an effective means of controlling oxygen concentrations.

Myth: Energy must be produced within the ecosystem.

No closed ecological system is completely enclosed. If it were, it would soon succumb to the laws of entropy, making it a very cold and dark place. Something has to enter the system, and that thing is energy. The energy driving the weather, the currents, and the very life on this planet is coming from the sun.

Getting it right

Most common energy sources:

  • Solar
  • Wind
  • Water
  • Geothermal
  • Gas
  • Fusion/fission

The first four examples are the only types applicable in a completely closed ecological system, since energy can be moved into the system without any exchange of matter. A major drawback, however, is that the habitat can’t leave the source of the energy. A spaceship powered by the sun will have a hard time operating in interstellar space.

Any technology that requires the use of combustible fuels or fissionable (uranium 235 or plutonium 239) or fusible (Hydrogen 2 and 3, deuterium and tritium, and helium) materials will have to be resupplied on a regular basis, so they are not suited for long term ecosystems. By nature of their bi-products, they cannot be reused for more energy, but they have the benefit of being disposable and can be used as a form of thrust in spaceships without upsetting the mass balance.

Other Considerations for Environmental Control and Life Support.

Ecosphere.jpg

My year old Ecosphere. Going strong except for a slight algae overgrowth (The lab decided to keep lights on around the clock this past month).

Size- Closed ecological systems can come in all shapes and sizes, but the larger the better. Larger ecosystems, like the Earth, can sustain much more life and complexity and take longer to collapse if poorly maintained.

Nutrition- The nutritional demands of a human are more than getting the right amount of calories. There are many essential trace elements, minerals, amino acids (9 of them), and fatty acids (omega 3 and omega 6) and nearly everything that is classified as a vitamin, that cannot be synthesized by the human body. Until these things can be synthesized by machines, a complex ecosystem of many different plant and animal life forms would be required to maintain optimum human health.

Temperature regulation- Heat will build up rapidly in most enclosed systems, even in the cold of space, especially when you have heat generating electronics around. Heat needs to be dumped back into space as thermal radiation, usually a high surface area radiator that circulates a fluid capable of picking up heat in the interior and then dispensing with it outside. The opposite may be true in the deep ocean or underground, where heat may be drawn out of the enclosed system, and insulation will be necessary.

Air circulation- This is particularly important in zero G space, where hot and cold air will no longer rise and fall, respectively. To prevent air stagnation, humidity fluctuation and condensation, air needs to be well circulated. Filters are also necessary to remove any particulate matter such as skin cells or microbes.

The human element- Most enclosed ecosystems designed to support human life have not lasted nearly as long as they were intended to. Why? Because they failed to factor the human element into the equation. People get lonely and fall in love, personalities clash and people fight. Close quarters and a limited food supply can cause even the most patient and respectful of people to lose their temper. In Biosphere 2, the eight crew were barely on speaking terms by the time they exited, and two of them got married soon after.

Writing Update-October

fall-in-seattleIt is Fall, a beautiful time of year in Seattle. All the leaves are changing color, and the days are either rainy, sunny, or a bit of both.  I wish I could blame the weather for the late writing update this month, but the truth is, I just forgot. I do have some fun blog posts planned, but you will have to wait till next week to see them.

My works-in-progress.

The thing I love most about this blog is that it allows me to research dozens of topics I would otherwise have no reason to research. In so doing, it has given me more ideas than I know what to do with. These ideas have found their way into my writing and into the outlines of several new works in progress.

In case you missed it in my last post, I am working on a new story called Grounded (working title). Quotidian is more dystopian than sci-fi, but Grounded is very sci-fi. You can read the blurb here. It will be set in the near future, just like Quotidian, but unlike Quotidian, it will be chock full of science and innovation. It has been fun learning all about orbital mechanics and buoyancy and speculating about what will change when gravity has been eliminated. I have even consulted with my uncle, who works for NASA. You will be hearing more about this project in the near future.

Editing.

Quotidian is coming along slowly. In my August update, I had planned to make it through several rounds of edits and several drafts by the end of the year, but I am still wading through the current draft. The hardest part it deciding what stays and what goes. If a subplot doesn’t contribute much to the overall story, character development, or setting, I eliminate it. Unfortunately, this means I have to comb through the draft and remove all mentions of it. The earlier the subplot is introduced, the more there is to eradicate as the story progresses.

Typically writers fall into one of two categories: underwriters and overwriters. I think I am an overwriter, but not to the extreme. As I am editing, my word count is shrinking, but not by much. I think I outlined it well enough that there isn’t a whole lot of extraneous exposition or excessive subplots.

I usually write my entire story as one Word document. It is easier to keep track of the drafts that way verses having a Word document for each chapter. I regularly make new versions of the same document with a new save date to ensure, if I lose one copy or make a significant change, I can return to a previous version if necessary. This has resulted in a huge file of documents over the years. I love graphs, so I plotted the word count for each of my document versions over time to get an idea of my writing pace and speed:

quotidian-word-count

Word count for Quotidian

The book started relatively high in word count, but this was mainly due to all the notes, outlines, and about a chapter or so of actual story. It was pretty slow to get started because I was finishing Book 2 of the Abyssian. I didn’t start making headway on Quotidian until the end of 2014. Of course, this didn’t last long. I had to graduate. The next several months were spent writing my dissertation and graduating. I started my postdoc about a week after my last day in grad school, and that week was spent packing my bags, leaving Alabama behind, and traveling across the country to Seattle. Once in Seattle, the setting for Quotidian, I felt much more inspired. During the day, I was in lab, but afterwards I would find a quiet place in some nearby café or bar and write, nearly every day, until I completed Quotidian. Now I am in the editing phase, and I am really missing the daily writing. I have since started Grounded, but juggling both is making editing and writing progress pretty slowly.

Thankfully, I get quite a lot of editing and feedback from members of Critique Circle. On this website, I post chapters to my private queue, and my queue members read and critique it. I only have 16 chapters posted so far, but will be putting all of them up by the end of the year. In addition to finding me some alpha readers, CC was able to generate some pretty cool stats for my posted chapters:

readabilityadjectivesnounspronounsadverbsverbsprepositionsdeterminersdistinct-wordsdirect-speech

The readability stats indicate what grade level the reader needs to have in order to understand each chapter. Mine is pretty standard for a book targeting a broad audience, I think. The other stats give me assurance that my writing style isn’t dramatically changing throughout the story, and they show me where I am heavy on description or dialogue. I highly recommend CC to other aspiring writers. When I get into some other editing software, I will be sure to post my reviews and recommendations.

As a side note, I was thinking about starting up a scientific consultant service to cater to writers’ specific story needs. I would probably do this service for free, unless demand rises rapidly. So if you are having trouble figuring out the science involved in your story’s unique context, or if you simply want someone to help you brainstorm, please feel free to contact me. I will likely not be an expert in the topic you need help with, but I do enjoy researching new things.

I am also happy to take suggestions for future blog posts. Any topic related to improving the accuracy and believability of science in science fiction is preferred.

That’s all for today. Back to writing… and editing, I guess.

The science of the presentation

presentationI am posting much later in the week than usual. It was a busy week. Most of my time was dedicated to analyzing data and preparing a research presentation for a group at the university. It was in preparing the presentation that I came up with the topic for this blog post. I realized that the mechanics of giving a presentation were very similar to the mechanics of writing a book. The goal is to make it sell.

I was lucky enough to be trained in how to give presentations by my first mentor, who was passionate about the mechanics of delivering presentations (he even gave a yearly presentation on how to give presentations). These were some of the main points he stressed:

Control the flow of information-

Don’t give any more background than the audience needs to be able to understand and appreciate the rest of the presentation. This is especially important when it comes to the content of individual slides. If you overload the audience with too much information at one time, they will become distracted from the heart of your message. Begin a presentation with a complicated scheme or figure and the audience’s eyes will wander to every part of it except for the area you want them to focus on. Worse, the audiences’ eyes might glaze over entirely when confronted with what appears to be a lecture. In a book, they call this an info dump, and it is a sure way to slow down a story and make people lose interest. In short, deliver the information only when they need it, and never more information than they need.

It is also important to deliver the information in a direct and logical fashion. If you are too vague and ramble, your audience won’t have gained anything in the time they spent listening. You want to anticipate their thoughts, giving them an answer right before they realized they had a question. This will keep them interested and give them confidence that you are an expert in the subject on which you are presenting. It follows that you should never bring up something you will not address or hope people won’t ask about. If you have a curious artifact in a piece of data, don’t draw attention to it, especially if you have no idea why it’s there or what could be causing it. You will be asked questions you can’t answer and the audience will get the impression you are ignoring something important, or just too dense to figure it out.

It is best to assume your audience is intelligent. Having a slide titled What is DNA? will be sure to offend all the geneticists in the room. By the same token, your sci-fi readers will not be pleased with a detailed description of why earth orbits the sun.

Which brings us to our next point.

Know your audience-

Delivering a presentation on muscle physiology and contraction kinetics to a group of geneticists is difficult. Trust me. So it’s important to deliver the information in a way that makes sense to them and gives them a bit of what they are expecting. You can judge your audiences’ reaction to a presentation by how many have fallen asleep in their chairs. On amazon, you can get an idea of your book’s success by number of reviews. At this point, it is too late to go back and fix things. Running these things past your lab or beta-readers will help you narrow down your audience.

If you are struggling to find a way to make your product (research or novel) interesting to the audience, it’s probably not your target audience, and you should not spend your time and effort on them. Selling a horror novel at a Romance Readers Conference is the definition of futile.

Be enthusiastic and confident-

Projecting enthusiasm and confidence is the best way to draw your audience in. But like all things, it is best in moderation. You can litter your presentation with animations and colors and media, just as thoroughly as you can fill your novel with flowery language, imagery, and description. But too much of it will be distracting and off-putting, and make it seem like you’re trying too hard, or compensating for a poorly plotted story or lack of data. Keeping things too colorless and dry, however, will come across as boring. If you sound bored, your audience will be bored too.

It’s okay to be a little nervous. When we put our stuff out there, whether it is in front of a lecture hall or on the virtual bookshelves of Amazon, anxiety is to be expected. I find that I am far more confident in my presentation if I have done a lot of preparation. This includes significant edits and revisions of my slides, and many practice runs with people willing to give me critiques. It is the same with my writing. I am far less nervous about my audience’s impression of my work if I know it is well thought-out and heavily edited for grammar, style, and structure.

 

Research presentations are a lot like books. The major difference is that your data shouldn’t be fiction (theorizing that your data is the result of ‘magic’ is frowned upon in most scientific circles). But no matter how much you prepare and polish, there will always be those who don’t care for your work and will criticize it. Don’t lose heart. You can’t please everyone… unless there’s free food involved. Nobody complains about free food.