“Why’re they pink?” Gus asked, pointing to his chest as he struggled with the donning procedure of a Carmine in his size.

“Carmine. It’s the colour as well as the suit,” Amon corrected him.

“Fine. Why are they fucking Carmine?”

Amon rattled off his lines like an actor jumping the mark. It put Gus on edge in a way he struggled to articulate.

“The area in which these suits saw action is tidally locked. That is, the strategically important areas on Volta are cast in a permanent twilight, which casts a pinkish hue over the entire region.”

“Carmine-ish,” Gus corrected him.

[Excerpt from Brigador Killers: Pilgrim by Brad Buckmaster]

Arriving at a particular design is one of the difficulties of video game development. “Just come up with something new” sounds romantic, but is often an ineffective approach. We find that the best designs are often authored in response to particular constraints; those can be story (the planet has a red star), practical (we only have two weeks to build this), gameplay (we don't have the sprite budget for this unit to animate), or even just arbitrarily self-imposed.

If you read our post on Reimagining The Spacers from last year, you’ll know what comes next: we went one step before that process to answer what might seem to be a simple question: why is the Carmine suit that colour? Naturally, we asked an astrophysicist to help us out.

The Carmine suit’s origins

Also known as a tactical rig or “tac rig”, the Carmine suit is less sturdy than a powersuit like the loyalist Mongoose. It makes up for this with increasing the player’s movement speed and kick power, as we have previously noted.

Within the fiction the suit comes from Volta, a mining colony planet mentioned in the text above. Voltan locals attempted a revolt with the use of these suits, though Volta is not a planet like our own.

Volta

Volta is different to both Novo Solo (where Solo Nobre is located) and Mar Nosso (where Brigador Killers takes place). There’s no specific mention of the following in the original Brigador, but if you listened to the prologue of the Pilgrim audiobook…

…At the 3:10 mark, you might have wondered what the word “terminator” means in this context.

On most planets like our own, the terminator is the ever-moving line that is the border between daytime and nighttime. In Volta’s case this line does not move. This is because Volta is tidally locked towards its sun, meaning one side of the planet is always facing that direction. Our own Moon is an example of this phenomenon, since it faces towards Earth. In the novel extract, the character Amon mentions “a pinkish hue over the entire region” but most of us have experienced twilight - that period where the Sun’s light is still scattering into the upper atmosphere despite being below the horizon…

…but these periods are not exclusively pink. Missing from the extract is what sort of sun Volta has. Enter Dr. Lindsay DeMarchi, an astrophysicist kind enough to consult us on the vagaries of living on a tidally locked planet.

What is a red dwarf?

Our sun in the solar system is a yellow dwarf. It’s about 0.5 degrees across, or in other words takes up approximately 1/720th of the sky. Volta’s sun is a red dwarf, which is 2.1 degrees across and takes up 1/180th of the sky. If we overlaid both planets’ skies into one scene, the stars might look something like this.

Despite the yellow dwarf looking smaller than the red dwarf, red dwarves are smaller in mass, have less luminosity and are cooler than a star like our Sun. Volta is also much closer to its star for two reasons. The first is tidally locked systems occur when bodies are close to one another, such as Mercury and our Sun (another example of tidal locking... kind of). The second is that Volta’s red dwarf has a cooler temperature and is less luminous than our Sun. This means the habitable zone for Volta needs to be within 0.030 and 0.043 astronomical units from the red dwarf to make up for the disparity in temperature and light compared to the Earth (which is ~1 AU from the Sun).

If you are wondering whether we did the math on any of this, absolutely not. The astrophysicist who does this sort of thing as their day job did the math, resulting in the following table:

Or, as a diagram:

We are aware that tidally locked planets might not be habitable at all. Dr. DeMarchi wrote to us the following caveat:

“Astronomers don’t yet know for certain the effect tidally locking has on the development of life. Would this cause a temperature gradient that triggers very strong winds? Would the opposite faces each be too hostile for life to develop? Would an atmosphere be able to exist at all, or would the cold side condense it all until it’s too thick to be a gas?”

Yet when it comes to the realism vs. fun debate in video games, we tend to lean towards fun because it’s far more interesting to assume that Volta is (just about) habitable and all the effects that might have on a local population.

Now that we know where Volta is and what sort of sun it has, what does any of this have to do with the Carmine suit being carmine?

Light, Or The Ornamental Force Of The Universe

Since Volta has a red dwarf and not a yellow dwarf, there is going to be a difference in the range of visible light on Volta. This means that Volta’s star isn’t putting out a lot of blue or green into the spectrum, which we get a lot of from our own Sun. Put blunt, this is what a Voltan rainbow might look like.

This isn’t the full list of colors visible, just a snapshot of what might appear. If you’d like to play around with what colors appear at different wavelengths, you can use this site. 

As the name of the red dwarf implies, Volta’s environment would appear very red on the surface. We arrive then at our answer as to why the Carmine suits are that colour: camouflage. There’s even precedent for this in an actual conflict.

The Pink Panthers of the SAS

A few years into the Dhofar War that took place between 1963 and 1976, Britain supported the then-sultan of Oman with the Special Air Service. One of the vehicles used in this conflict by the SAS was a run of 1968 series IIa Land Rovers painted entirely in pink. This vehicle can be seen on display in the British Motor Museum in Warwickshire, England.

The reasoning behind this choice of colour is that it turns out pink was effective at disguising the vehicle in Oman, the geography of which is mostly desert and valley. The colour scheme would later be abandoned when it was replaced with the sand-coloured SAS 110 Desert Patrol Vehicle in the 1980s.

If you’re voracious for more physics, you might have missed this lengthy chat our designer Hugh had with another physicist friend discussing the rationality behind the proposed form of space travel in the Brigador universe. Enjoy.

[Special thanks to Dr. Lindsay DeMarchi AKA @stellarmorticia who also went to the trouble of explaining several other things, like why bees would not do well on a planet like Volta due to the lack of UV light from a red dwarf.]