Worldbuilding

Add one mind-controlling alien . . .

Posted on by Chris McMahon

Every epic tale needs its villain. My new Fantasy book Warriors of the Blessed Realms is written against a backdrop of multiple worlds, and follows the adventures of heroes like Finn, from the Blessed Realms, and Liam, from Brisbane in Australia, as they fight the dark forces of the Vault of Seven Horns. They seek to defeat the plans of a cruel overlord, and rescue a captured priestess from a dark ritual that will give their enemy a vast increase in power. So who is the villain? Add one mind-controlling alien . . . the krell lord VoYannan!

So who are the krell? They are a solitary species that propagate without sexual union. Somewhere in their evolutionary history they took a dark, inward turn. In order to reproduce a krell must implant a krell-spawn into a host. The spawn grows in the host as a parasite until it rips its way free as a fully conscious krell. Nice eh? Heh – they are the bad guys! Each new krell possesses all the memories and talents of their progenitor, but their power as newborn krell depends on the choice of host. This is the fate of the captured priestess Sephany — unless our heroes can reach VoYannan’s ruined world and rescue Sephany from the depths of VoYannan’s dark citadel.

So why would a krell — who are always jealous of their power and control — loose a generation of krell-spawn on the universe? Because the sire and the newly born krell are mentally linked. The newly emerging krell can be leashed to their parent, and enhance the parent’s power. Yet there is a trade-off. As the new krell grows in strength, they can in turn consume and destroy their parent, as VoYannan did to his own progeninitor.

Krell don’t socialise well. In fact, they pretty much want to kill and dominate each other. Yet new krell keep coming.

The krell have awesome mind-control powers. Lord VoYannan, the ruler of the Vault of Seven Horns, controls fifty-eight planets, and dominates millions of sentient beings through direct mental control. He draws power from each, and enhances his power with each new mind brought under his control.

The Vaults themselves are dystopian SF worlds. Oppressed millions are kept in check by legions of laser-wielding brutes called Siithe, a savage race that consumes their victims (and even each other if they get the chance). Here are leaden skies, vast ruined cities, and factories manned by slaves from dozens of conquered species.

So, about the story . . .

Warriors is an epic tale spanning multiple worlds and multiple genres — fantasy, urban fantasy, and SF — where magic and high-technology go head-to-head.

VoYannan plots to unleash a devastating assault on the Blessed Realms, a coalition of six worlds with benign technology that is dedicated to preserving life. He uses an ancient Gateway on Earth to strike. His Vault forces capture the priestess Sephany, crucial to his plans, and escape.

Realm warrior Finn Evenstone sets off in pursuit, but cannot pass the Gateway used by the Vault.

Liam Durrow, sole survivor of an ancient Earth lineage, is led to Fraser Island by a vision, and uses his unique magical abilities as Keeper to open the Gateway.

Both Finn and Liam are soon battling the Vault on Earth, and in the Shadow Worlds, planets already ruined by the krell. They need all the help they can get. They are joined by tenacious Federal Agent Yolinda Paris, who has her own score to settle.

Check it out! Grab a copy of the book! Available at selected bookstores and these online retailers!

Avid Reader Bookstore

Amazon – Print and kindle

Barnes & Noble – Print and Nook

Google Books – Print

Booktopia – Print

Bookdepository – Print

Fishpond – Print

Waterstones – Print

Kobo – ebook

eBay – Print

itsi – epub

What is a Realm?

Posted on by Chris McMahon

My new novel, Warriors of the Blessed Realms is out into the world, but what is a Realm?

In the exact sense, a “realm” is a community or territory over which a sovereign, such as a king, rules. Or an area or sphere of certain knowledge or activity.

In the case of Warriors, a Realm is a world. A planet.

And there are many worlds in this epic tale. One of them is Earth itself, where the story starts with central character Liam Durrow.

The Vaults of Sheol are fifty-eight planets ruled by a ruthless mind-controlling alien warlord, VoYannan, one of a solitary species called a krell that can dominate millions, growing in strength with each new mind that falls under their sway.

The Vaults are dystopian SF worlds. The enslaved populations are kept in check by legions of laser-wielding brutes called Siithe. Here desperation breeds under leaden, cloud-filled skies, which lower over vast ruined cities, while factories manned by slaves from a dozen conquered species churn out weapons of destruction.

Standing against VoYannan is The Blessed Realms, a coalition of six worlds with benign technology that is dedicated to preserving life, with magic that can stop Vault technology in its tracks. The Realms have fought VoYannan for thousands of years, containing him with steel and magic.

VoYannan plots to unleash a devastating assault on the Blessed Realms. He uses an ancient Gateway on Earth to strike. His Vault forces capture the priestess Sephany, crucial to his plans, and escape.

Realm warrior Finn Evenstone sets off in pursuit, but cannot pass the Gateway used by the Vault.

Liam Durrow, sole survivor of an ancient Earth lineage, is led to Fraser Island by a vision, and uses his unique magical abilities as Keeper to open the Gateway.

Both Finn and Liam are soon battling the Vault on Earth, and in the Shadow Worlds, planets already ruined by the krell. They need all the help they can get. They are joined by tenacious Federal Agent Yolinda Paris, who has her own score to settle.

That that’s Warriors! An epic tale spanning multiple worlds and multiple genres — fantasy, urban fantasy, and SF — where magic and high-technology go head-to-head!

Check it out! Grab a copy of the book! Available at selected bookstores and these online retailers!

Amazon – Print and kindle

Barnes & Noble – Print and Nook

Google Books – Print

Booktopia – Print

Bookdepository – Print

Fishpond – Print

Waterstones – Print

Kobo – ebook

Walmart – ebook

eBay – Print

itsi – epub

The twin Earth almost had

Posted on by Chris McMahon

It’s hard to imagine Mars as a wet place, but that’s exactly what the data and images coming in from the Curiosity rover in Gale Crater are telling us. In fact, Mars is the twin Earth almost had.

Wet Mars.

3.5 billion years ago Gale Crater was filled with ponds of water, with streams cascading down the ancient basin’s walls, down to its wet centre. Eventually these watercourses dried up, but then perhaps the whole cycle repeated numerous times. Of course the water did eventually go for good.

Why?

Unlike Earth, which has a powerful magnetic field protecting its atmosphere, Mars has no such advantage. The solar wind — all those energised particles — just ram straight into it, knocking molecules right out of its atmosphere into space. Which molecules go first? The lightest ones. The hydrogen, the water, the oxygen. What is left is the heavier molecules like carbon dioxide, purely by virtue of the balance between gravitational attraction and the applied force of that solar wind. But that’s planet formation!

How do scientists conclude that there may have been these super wet and dry periods from the geology? By evidence left in the rocks, specifically high concentrations of mineral salts, deposited during periods of evaporation. This is not the first time Curiosity has found evidence of water here. The rover has also unearthed evidence of freshwater lakes.

Gale Crater: Source NASA JPL

The Gale crater itself started life with a bang, and is thought to have been formed by one massive impact. Sediment on the floor of the crater was built in layer upon layer of alluvial deposits, drying into a substantial formation over time. This layered rock was later wind-eroded to form the current Mount Sharp, which Curiosity is busily climbing.

So, we know there was water there, and likely there for long periods of time. The 64 million dollar question is, was this wet environment capable of supporting microbial life at the surface, and if so, for how long? How long were evolution’s engines allowed to turn, working to transform that life? And is that life still present?

If not for the weak magnetic field of Mars, we could have had a celestial twin. A planet in our own solar system with water-based life. Now that is something to think about!

Studies like this are invaluable in understanding our own home. As a SF writer, they provide invaluable insights when it comes to building your own planets! Check out my own world-building in The Tau Ceti Diversion.

With the crew dead, and the starship’s fusion drive held back from a lethal explosion, Karic and the surviving officers reach a habitable planet – the last thing they expected was to find it already occupied . . .

Get it now on Amazon!

Can We Guess Why Warmaker is a Standalone Novel?

Posted on by Chris McMahon

Brandon Sanderson is probably my favourite living fantasy writer, and has published some highly entertaining and multi-faceted fiction in notable series such as the Way of Kings, but with all these successful series can we guess why Warmaker is a standalone novel? Or his debut novel Elantris for that matter?

It’s not as though Warmaker lacks anything in the thoroughness of the world’s depth or texture. All the backstory, the unique magic system (involving the use of “breath”), the fascinating characters such as sisters Vivenna and Siri, the indolent Returned  Lightsong and other scheming Returned that are worshiped as gods in Hallandren, along with the remote God-King, who is not all that he seems.

So why write Warbreaker as a standalone?

The first and most obvious guess is that this was the size of the idea. As many writers will tell you, some ideas come in short story length, other as novellas, while others have such breadth they demand the broader canvass of the full novel. The key is what is driving the story. What was that core idea, that first “wow” moment that gave the impetus for the world’s creation in the first place?

For Warbreaker, I find that key idea difficult to pin down. Did Sanderson have the idea for the magic system and then create the story around it? One of the things I do love about Sanderson is the invention in his magic systems – look at the use of metals for magic in the Mistborn series. The magical sword in Warbreaker is particularly entertaining (don’t worry it’s introduced early).

 

Or is it in the characters? The backstory does link the key villain to the royal line, of which Vivenna and Siri are scions. Was it the character development of the two princesses that drove the story for Sanderson? I guess if that was the case, its resolution would present a natural end point.

What do you think?

 

 

 

 

 

 

Want to check out Chris McMahon’s fiction?

The Tau Ceti Diversion, the first interstellar exploration vessel Starburst sets out from Earth in 2157, but this is no NASA science mission, it’s funded by the mega-corporation ExploreCorp. On approach to the planet Cru, the Starburst is hit with a surge of deadly radiation that kills most of the crew and disables the ship. It’s a fight for survival as sub-Commander Karic struggles to get control of the fusion drive before the ship turns into a giant hydrogen bomb.

 

 

 

 

 

In The Calvanni, first of the three-book fantasy series, The Jakirian Cycle, Cedrin, a street-wise calvanni (knife-fighter), is summoned to the secret underground tunnels of the Brotherhood and forced to join in a rebellion. Caught between the threat of death and his suspicions that all is not what it seems, he must try to keep his friends alive and escape.

 

Atmosphere on a Fictional Planet

Posted on by Chris McMahon

So you’ve got your story working, but how do you sketch out the atmosphere on a fictional planet? Maybe you have some idea of the mass, radius and gravity and you’ve got the orbit in the ‘sweet spot’ goldilocks zone where liquid water can be present on the surface, but what will conditions on the surface actually be like?

What sort of factors go into whether that planet, presumably an Earth-like rocky world, will have an atmosphere that can support terrestrial life?

Planets above a blue planet

The gravity of the planet is one key variable, along with surface temperature, and the strength of the planet’s magnetosphere, which can protect against atmospheric stripping due to solar wind.

The surface temperature of a planet will determine how much kinetic energy, and so velocity, the gas particles will have. If that temperature, and velocity, is high enough it will exceed the planet’s escape velocity and the molecules will fly off into space like tiny spaceship explorers. Earth has lost most of its very light gases like hydrogen and helium in this way, whereas the gas giants have enough gravity to retain them. We kept our water, and we’ve got a lot of it! If Earth was sitting where Venus is things would be different, the additional temperature would give those lighter gases like water vapour enough energy to escape, and also prevent any being trapped on the planet’s surface itself (whereas some is ‘sequestered’ on Earth as water and ice at our lower surface temperature). But beyond the early, settling down period where the lighter gases are lost, any world larger than Earth, orbiting in that goldilocks zone, will not continue to lose a significant proportion of its atmosphere through thermal processes.

Here’s a cool pictorial on thermal escape (source: Wikipedia).

Solar_system_escape_velocity_vs_surface_temperature.svg

Beyond that thermal stripping process, is where the magnetosphere comes into its own, deflecting the solar wind – one of the main non-thermal processes leading to atmospheric loss. The very thickness of a planet’s atmosphere (retained due to its gravity, and as a function of surface temperature), will also protect a planet from the solar wind, even in the absence of a magnetosphere. It’s thought that Venus’ thick atmosphere, ionized by solar radiation and the solar wind, produces magnetic moments that act out to 1.2-1.5 planetary radii away from the planet to deflect the solar wind, much like a magnetosphere (but an order of magnitude closer to the planet). In fact, it’s thought the dominant non-thermal atmospheric loss process on Venus is actually from a type of naturally induced electrical acceleration. On Venus, the stripping of the lighter electrons from the atmosphere causes an excess of positive charges, accelerating ions like H+ out of its atmosphere.

Our explorers need a breathable atmosphere, but they also need an atmospheric pressure like our own Earth’s.

My fictional planet of Cru, in the Tau Ceti Diversion, has comparable surface temperatures to Earth, but a higher surface gravity. The higher surface gravity, and its lower density, allowed me to assume a lighter atmospheric composition, and allow an atmospheric pressure, or weight of atmosphere, close to surface much like Earth’s. That atmospheric composition is crucial to having a reasonable atmospheric pressure – its not just the gravity of the planet. Venus, even though it has slighter lower gravity than Earth, has a crushing atmospheric pressure of 90 times Earth’s due to its heavier  atmosphere of CO2.

Check out what my my intrepid explorers found in my novel The Tau Ceti Diversion when they touched down on the planet!

Read it now on Amazon!

Tau-Ceti-Diversion-severed-ebook-cover (Medium)

Return to Elantris

Posted on by Chris McMahon

I recently make a return to Elantris – the first published work by Brandon Sanderson. Elantris is also the name of the great city of immortals where all the trouble begins and ends. What a great story.

Sanderson would have to be one of my favourite living writers. He manages to combine great storytelling with inventive worldbuilding of an outstanding scope.

My memories of Elantris centred around the core mystery of the book – how the virtually immortal godlike Elantrians lost their power (don’t worry, that’s no spoiler, you find out on page 1), and the PoV of the prince Raoden who is cursed at the onset and thrown into the fallen city in secret while his royal father declares him dead to the world at large.

When I re-read the novel I realised it held so much more. I had forgotten about the two other major PoV characters for a start: Sarene, Raoden’s bride-to-be who becomes stranded in Arelon, a widow despite the fact that the political marriage never went ahead (thanks to the strange marriage contract), and the warrior-priest Hrathen, who is on a mission to convert the entire country to his militant faith before the theocracy that sent him descends on Arelon in a not-so-holy crusade of destruction and domination.

The twists and turn of the plot, and the intrigue are highly developed, and Sarene and Hrathren become opponents on opposite sides of the political divide, slowly winning each other’s respect. The book has a strong romantic arc, with Raoden and Sarene making a slow dance toward each other and eventually uniting in common cause at the conclusion. The depth of characterisation is definitely a plus for the book, as is the wide range of secondary characters, which all enhance the plot.

There is so much more in this book than I remembered. The development of so many themes through the storyline and characters, from politics and different political models, to the credible, and chilling, tactic of using hatred to unify an political faction. The exploration of different leadership models, the strange mix of mercantile meritocracy and feudal system used in modern Arelon, the democracy of a now vanished republic (destroyed by the theocratic empire of Hrathen’s people), and the benign leadership of the old godlike Elantrians before their magic failed.

The worldbuilding is so extensive, and solid, the setting so convincing, I can hardly believe the book is a standalone. I was left wondering if the additional character arcs and complexity was lost on me the first time, or if I had just forgotten it.

If you like fantasy, and have never read Sanderson’s first novel, it’s well worth the read!

 

Estimating Surface Gravity on a Fictional Planet

Posted on by Chris McMahon

So you want to estimate surface gravity on a fictional planet? Easy!

One of the things I had to do as part of the rework of my novel The Tau Ceti Diversion, is to try and work out the surface gravity of my fictional planets. From the Kepler data, there are two exoplanets located in the Tau Ceti system that are likely to be in the system’s habitable zone, or where there is the possibility of liquid water on the surface, and perhaps life as we know it.

To play around with my estimates of gravity, I used ratioed rearrangements of Newton’s law of gravity (law of universal gravitation) and a simple formula relating the density of a spherical planet to its mass and radius (these are at the bottom of the post in the ADDENDUM).

WARNING: MATHS CONTENT!!!

Here’s Newtons famous law:)

law of gravity

The two planets thought to be in Tau Ceti’s habitable zone are denoted Tau Ceti e and Tau Ceti f. What is known about these two planets is their likely orbit, eccentricity, and their mass. All of these properties have been derived by calculation, based on observed data, so are all known to within appropriate error bounds, but I’m leaving the error off my scribblings so things don’t get too messy.

Tau Ceti e is thought to be around 4.3 Earth Masses, or Me (i.e. 4.3 times as heavy as Earth), while Tau Ceti f, the planet that orbits a bit further out, is thought to be around 6.67 Me. For the astronomically minded, these two planets orbit at around 0.55 and 1.35 AU from Tau Ceti respectively.

So, here’s where I cheated a bit, like any good engineer. I started with the answer I wanted and calculated backwards to see if the answer I wanted led to reasonable base assumptions. This is not as cheeky as it sounds, because when you have an insoluble problem (i.e. not enough data is known for an explicit result), an iterative approach is often used.

For my story to work, I needed a surface gravity on my planet of no more than 1.2g – that’s twenty percent higher than Earth’s. But how could I get a gravity that low on a planet that was over 4 times the mass of Earth? The answer is that surface gravity is a function of mass and radius, or going a step further along the calculation path, mass and density.

I used a ratioed form of Newton’s law that allowed me to relate the ratio of two planets gravitational forces to the ratios of their masses and radii. I already knew the ratio of the gravities ( assumed at gTCe/gE= 1.2) and the ratio of the masses (MTCe/ME =  4.3), so could calculate the ratio of radii (rE/rTCe) at 1.89.  Using another formula that related the ratio of the two planet’s densities to their ratioed mass and radii, I could then calculate their ratioed densities (dens TCe/ densE) at 0.63. So at the end of all that, to have a surface gravity of 1.2 g, Tau Ceti e would have to have a density of 63% of Earth’s. Is that reasonable?

The density of Earth is 5.514 g/cm3, not too much different from the density of a rocky planet like Mercury (5.427 g/cm3), but a lot higher than other solar system planets like Jupiter and Uranus (1.326 g/cm3 and 1.27 g/cm3 respectively), comprised of lighter materials. A surface gravity of 1.2g on Tau Ceti e would put its density at around 3.5 g/cm3, less dense than our own rocky planets, but certainly in a feasible range.

So what sort of densities would you expect for the Tau Ceti system? One clue is the metallicity of the system, which is a measure of the ratio of iron to hydrogen in the star’s makeup. In the case of Tau Ceti, this is estimated to be around one third of our own sun. This indicates the star is likely to be older than the Sun, made up of stellar remnants left over from less evolved stars that have not had time to form as much of the heavier elements in their internal fusion factories.

So Tau Ceti is made up of lighter elements. Based on this, it was reasonable to assume that the planets in the Tau Ceti system would also be made up of proportionally lighter elements, and quite possibly in the range I had estimated. Tau Ceti e and Tau Ceti f are also large planets – much larger than our own Earth – so having a density in between Earth and our own gas giants also made sense to me.

Using the same planetary density I had calculated for Tau Ceti e, for the larger Tau Ceti f, gave me a surface density of around 1.4g for the bigger planet – just a little too high for feasible human colonisation – and that fit nicely with my story as well.

It was a lot of fun playing with these calculations, and thankfully the known science fit with my story, at least with some comfortable wiggle room!

Check out what challenges that increased gravity provided for my intrepid explorers in my novel The Tau Ceti Diversion!

Read it now on Amazon!

 

 

 

 

 

 

 

 

ADDENDUM

For those interested in the maths. . .

Density formula:  densp= Mp / (4/3*pi()*rp^3)

Where:

densp= Density of Planet (kg/m3)

Mp = mass of planet (kg)

rp = radius of planet (m)

In ratio form: densp1/densp2= Mp1/Mp2 *(rp2/rp1)^3

 

Ratio of Newtons law relating gravity, mass and radius of two planets:

gp1/gp2= Mp1/Mp2 *(rp2/rp1)^2

 

Evolution, Insects & Oxygen

Posted on by Chris McMahon

One of the key elements of my novel the Tau Ceti Diversion was the unique setting I imagined for the story. Specifically, an alien planet where the top evolutionary niche was filled by an intelligent insect race.  So I needed to think about insect evolution, and how that evolution was affected by the amount of oxygen those insects could take in from the planet’s atmosphere to fuel their metabolism.

Now, it wasn’t going to be too much fun to have my human crew menaced by determined ladybugs or extremely intelligent grasshoppers two inches long, so I needed big insects! I needed a world where the entire biosphere – every single evolutionary niche, both large and small – was filled with insectoid life.

You think people shudder when they have to shoo an insect out of the living room window with a rolled up newspaper, how about having to face a three metre tall intelligent being, staring back at you with multi-faceted insect eyes? Creepy? Stay calm space-explorers!

dragonflycaterpllar lifecycle_thumb

On Earth, insects are small, and a variety of other life has evolved to claim the top evolutionary spots in the food chain.

The size of insects on Earth has been constrained by two main factors, the way they take oxygen into their bodies, and the amount of oxygen in the atmosphere. Change those two things, and everything changes. Insects were here first. If not for those two constraints, our little furry ancestors would probably never have made it out of their burrows, let alone up the primate tree.

Earth’s insects don’t actually breathe in the way that mammals do. Our insects take oxygen into their bodies through the process of diffusion, the precious oxygen passing across membranes directly into their cells, with waste gases passing out of the cell walls in the other direction. Our insects have a series of holes in their abdomen, called spiracles, that allow air to enter their bodies. From there, incoming air moves into a network of tiny tubes called tracheae. The biggest bugs have the longest tracheae, to allow them to get the most oxygen into their bodies.

Insects have a very limited ability to use their oxygen absorption equipment. They can open or close the spiracles by muscle contraction, and they can also pump muscles inside their body to try and increase the amount of air passing through the tracheal system, but to limited effect. The amount of oxygen they can extract from the air is always going to be limited by the tracheae shape and the rate of  oxygen diffusion through the cell walls.

In the Tau Ceti Diversion, human explorers come face-to-face with evolved life dominated by insects, thanks in part to the planet’s high oxygen atmosphere, and an evolutionary adaption of the alien insects that has given them true lungs.

That’s not to say Earth didn’t have some big insects. At the moment our atmosphere has around 21% oxygen (by volume). The concentration of oxygen in the air has gone up and down throughout Earth’s history, mostly in response to what was happening in the biosphere. Toward the end of the Carboniferous periods (300 million years ago), oxygen peaked at a maximum of 35%. At this time there were some pretty impressive insects – like dragonflies with wingspans of over a metre in length. That’ s one hell of an insect, and all with basic air diffusion to get the oxygen into its body.

On my fictional planet of Cru, orbiting Tau Ceti, the oxygen concentration in the atmosphere is more than 30 percent, which certainly makes things fun for the explorers. They not only have to deal with huge insect life, but also have to deliberately moderate their breathing to prevent hyperventilation, and they have to be careful how all that extra oxygen makes any sort of combustion in the atmosphere more aggressive.

My novel, The Tau Ceti Diversion, is a story about our search for new planets to colonise outside our solar system. Much of the action takes place on planet tidally locked to Tau Ceti that has some rather unique life forms. The novel is due to be launched on September 1st 2016 – not long now! – and pre-order is available on Amazon! Read more about what happens in the story here!

Stay tuned for a free chapter download, coming soon!

Tau-Ceti-Diversion-severed-ebook-cover (Medium)

 

Day Side & Night Side – Tidal Locking of Planets

Posted on by Chris McMahon

So what is tidal locking? Our Moon is tidally locked to the Earth, always presenting the same face to us. That doesn’t mean that the Moon is stationary, far from it, it just means that it takes just as long to rotate around its own axis as it does to revolve around the Earth. The same thing can happen for planets, which can be tidally locked to their stars, always presenting the same side of the planet to their star, giving those planets a permanent ‘day’ side and ‘night’ side.

We could expect these planets to have some pretty unique characteristics, with a hot, dry side, and a frigid frozen night side. Some scientists have even dubbed them ‘eyeball’ Earth’s due to the likely combination of features that might develop.

one-side-planet eyeball earth

Source: space.com

In my SF novel, the Tau Ceti Diversion, the action is set on a planet that is tidally locked to Tau Ceti, always divided into a hot day side and a cooler night side. This set up was crucial to the novel, and to the civilisation that the stranded crew of the starship Starburst find when they land on the planet’s night side. Actually they were aiming for the terminator – the dividing line between the day and night sides – expecting this to be a temperate zone. But I can’t say much more without spoilers:-)

Tau Ceti is a G-class sun, around 12 lightyears from Earth. One of our close stellar neighbours. Could we expect that one of its planets would be tidally locked to its star?

Well, it did not take me too much research to realise that this is one very complex question. It would indeed be surprising to find a tidally locked planet around Tau Ceti. Finding a tidally locked planet might be more likely around a smaller M class star. But there are many, many variables that might allow a planet to become tidally locked to its star within a reasonable fraction of that star’s lifetime. The variables that might increase the likelihood of a planet becoming tidally locked early in the star’s lifetime include the lack of a companion satellite (i.e. more likely if there is no moon), a low initial rate of planetary spin, a low dissipation function (the rate at which mechanical energy is converted into heat), a low rotational inertia . . . even the rigidity of the planet can be variable.

So, all these variables gave me enough wiggle room to allow my planet to be tidally locked. Plus I had a secret weapon – a key bit of backstory that affected the planet’s spin at a key point of its history. But I can’t say anything about that either, not without giving away the story!

Stars are classified based on their spectral characteristics. The M-class spectrum contains lines from oxide molecules, particularly TiO, with absorption lines of hydrogen typically absent. M-class are the most common of stars, representing over 76% of our stellar neighbours.  So we might expect more than a few tidally locked planets out there. Of course these will be the smaller bodies, Earth-sized and smaller, so will not be well represented in our current exoplanet catalogue, which features a lot of big, Jupiter-sized and heavier planets due to the methods used to identify exoplanets (so far). M-class stars are light orange red in colour, from 0.08-045 solar masses and low luminosity (less than 0.08 of our Sun’s). This class features rare and exotic creatures that can rarely be seen by the naked eye, mostly red dwarfs, although some are red giants, or even red supergiants. The class also includes the intruiging brown dwarfs, which are ‘late’ class M stars.

My novel, The Tau Ceti Diversion, a story about our search for new planets to colonise outside our solar system, is due to be launched on September 1st 2016, and pre-order is now available on Amazon! Read more about what happens in the story here!

Stay tuned for a free chapter download, coming soon!

Tau-Ceti-Diversion-severed-ebook-cover (Medium)

Tattoos in Fantasy

Posted on by Chris McMahon

Cropped A3 Poster with Red Button
I’ve always been intrigued by tattoos. The awesome finality of having your skin inked has made me even more fascinated by traditions where tattoos carry a special meaning, such as the Polynesian cultures.

In my fantasy world of Yos, tattoos carry very particular meanings. Men and women are tattooed with a totem on coming of age, which has a religious meaning and marks inclusion in a particular sect and tradition – men inked on the chest and women on the cheek.

Then, both men and women gain tattoos that show their chosen path in life, their achievements and honours. This is so central to the cultures of Yos that to cover your chest (it’s a warm world) is a sign of deceit. Warriors will only wear armour in full-scale conflict.

In a world where many cannot read or write, the tattoos give a person’s history at a glance, where honour – and dishonour – is written in ink.

Here’s the cover from The Calvanni, that shows some of the tattoos of the Way of the Calvanni – or knife-fighter.

Calvanni front cover (Small)

Do you have any special tattoos that carry a particular meaning for you?