Fermentation

Last week’s blog post, all about alcohol and law, triggered a number of interesting discussions, and one of them (from a Goodreads friend) has inspired this post. It all started with my brief comment about the prospects of brewing on the ISS, up in the microgravity of low earth orbit. But before we get into space, let’s think about what happens during fermentation. (I’m going to mostly focus on beer in this post but similar comments could probably be made about wine).

Beer making in the Egyptian 6th dynasty (British Museum)
Beer making in the Egyptian 6th dynasty (British Museum)

People have been brewing beer for many thousands of years – in Egypt the process was well-organised long before 2000BC, and the earliest confirmed evidence for beer-making that I am aware of is from the 5th millennium BC, at Godan Tepe in modern Iran. I strongly suspect the history is much longer, and that more evidence will turn up in time.

Pottery beer jar, Egypt, c. 1600BC (British Museum)
Pottery beer jar, Egypt, c. 1600BC (British Museum)

Beer making has been credited with all kinds of benefits to humanity, including driving an early wave of technological development. Quite apart from the enjoyment factor. Back then, and for a great many years subsequently, beer was made in open fermentation vessels – basically very large pottery containers, semi-porous and so holding on to residues of yeast and the like. It was often a spin-off of the bread-making industry, seeing as how you needed yeasts and grains for both. Both bread- and beer-making have had, at times, vaguely magical or alchemical associations – these very ordinary foodstuffs are hidden away in a very ordinary vessel, and over the course of a few days they transform into something quite extraordinary. In early times, hops were not added (this seems to have been introduced in the middle ages), but people did sometimes add other flavourings such as fruit or spice extracts.

A 16th century brewery (Wiki)
A 16th century brewery (Wiki)

Now, during fermentation the yeasts work with the various sugars in the raw mixture, together with oxygen in the air at the top surface, and convert these into alcohol and CO2. The process is self-limiting – yeasts eventually kill themselves in too high a proportion of alcohol, so fermentation slows and stops. A brewer can choose whether to let the process go on to completion, or stop it early. An early finish means lower abv (alcohol by volume… the strength of the brew) and a sweeter drink. In olden days, I suspect brewers had conventions about how many days to leave the mixture – nowadays brewers have a more mathematical set of targets to do with final abv balanced against taste. Also, large breweries are very interested in keeping consecutive batches consistent about strength and flavour, whereas a domestic brewer, or someone in pre-industrial days, was less bothered about this.

Finally, carbonation. If you are brewing in an open-top vessel, all the CO2 generated simply goes out into the air. And if you are brewing at room temperature, especially in a hot climate like Egypt, not much gas is held in the liquid anyway. Nowadays we brew and store beer at specific temperatures in order to achieve a target level of carbonation. The colder the beer, the more gas it can retain, and then release as the drinker opens it up at room temperature. You brew for the preferences of your target market – lots of fizz (as in many lagers) or hardly any (as in many real ales).

Fermentation vessels - Grasmere
Fermentation vessels – Grasmere

That brings us onto the specific issue that triggered these fine discussions. What happens in low gravity? Not a problem in ancient Egypt, but looking ahead it’s an issue we will want to solve. Consider a modern fermentation vessel – a cylinder, usually with a cone at the base, and considerably taller than a person. As yeast ferments here on earth, different groups of yeasts arrange themselves at different levels in the vessel – some near the top and others near the bottom. This reflects slightly different ways in which they turn the sugars into alcohol… the sugar level varies in a gradient as you go up and down the vessel. As the yeast becomes exhausted, and starts to die because of the alcohol percentage, the yeast particles sink into the cone, taking with them some of the other residues like hops, grain particles and so on. The beer slowly clarifies by itself, though most brewers also use specific methods to end up with a clear rather than cloudy beer.

The ISS in low earth orbit (NASA/JPL)
The ISS in low earth orbit (NASA/JPL)

That’s fine here on Earth… but in orbit several problems arise. First, there is no real sense of up and down. So a yeast that is used to being near the top of a vessel, with its preferred environment of sugars and whatever, does not know where to go. Likewise, as they finish their job and die from overindulgence in alcohol, there is no “down” direction into which they can settle. Finally, there’s no particular reason why the liquid would stay in one clump – you could easily end up with several disjoint blobs of liquid, with varying proportions of the yeast you had added, each fermenting to different extents.

Centrifugal Fermenter (speculative!)
Centrifugal Fermenter (speculative!)

So this was the point I got to in my Goodreads discussion, which triggered several follow-up chats here in Grasmere. Not that we’re (yet) planing on an orbital version of our various beers and ales, but it is good to be ready for the future! The best answer we could come up with was to artificially introduce a sense of up and down by means of a kind of slow-speed centrifuge. Not so fast as to drive all the solid matter to the outside too quickly, seeing as you need it spread through the liquid at first, but fast enough that the liquid stays in one body, and the yeast can tell which tell which way is up and down. (As a side issue, you’d probably want two of these, rotating in opposite directions, so as not to off-balance the space station itself).

The fermentation will generate CO2, and you don’t want to just dump that into the cabin air supply, so you capture that with a safety valve coming out along the spindle (the “top” of the vessel). That can then either be kept for later use – as many breweries fixed here on Earth do, so as to reuse a resource which costs real money – or fed slowly back into whatever air-purification system takes your fancy. When the time comes to clarify your beer, you just spin the centrifuge faster and let the solid particles accumulate in the “bottom”, taking the splendidly clear beverage out of the “top”.

Artwork, astronaut drinking on the moon (WallpapersByte)
Artwork, astronaut drinking on the moon (WallpapersByte)

Bottling would be an interesting task, since yet again it is something that here on Earth relies on gravity as well as some back-pressure to get the liquid where you want it to go. But if you’ve successfully got this far, I’m sure that the final stage of getting your finished beer into some kind of container would not be an insuperable problem. In orbit you want low carbonation anyway – the last thing you want is for some rogue container to fob frothy mix all around the interior of your capsule. So you keep the whole thing chilled, to hold the gas in suspension in the liquid, and in any case you aim for a quiet liquid rather than a lively one! And voila – you have Orbital Beer, and happy astronauts…

As mentioned very briefly in Far from the Spaceports, concerning the legendary Frag Rockers bar,

“You’ll need to go to Frag Rockers to get anything decent. Regular fermentation goes weird in low gravity. But Glyndwr has got some method for doing it right. He won’t tell anyone what.”

For the curious, here is a British Museum video of recreating an ancient beer-making process based on what we know of ancient Egypt…

 

Another Alexa skill – Grasmere Brewery

Grasmere Brewery Alexa Icon
Grasmere Brewery Alexa Icon

Another of my Alexa skills has gone live – Grasmere Brewery, to be found at https://www.amazon.co.uk/dp/B07L8WK3Y9/ – UK only at present but rest of world to follow in a few days. Here’s the skill description…
“In this skill you can find out about Grasmere Brewery – where we are, and the range of beers we make, together with a selection of fun and interesting facts. We don’t sell our beers through Alexa, but you can find out how to buy them here. As with all alcohol products, we urge you to enjoy our beers responsibly.”

***Stop Press***

To my surprise, the skill has already gone live at other international Alexa market places – US, CA, AU, NZ, IN – as well as UK. I thought it would take a bit longer than this!

For example the US link is https://www.amazon.com/dp/B07L8WK3Y9/

Laws, qualifications, and the drinking of alcohol

University of Cumbria at Barrow - where I took the course
University of Cumbria at Barrow – where I took the course

I heard today that I had passed the study element of a Personal Alcohol Licence, which (after I have gone through a police background check and a few other formalities) allows me to authorise the sale of alcohol in England and Wales. Not in Scotland, Northern Ireland, or indeed anywhere else in the world, but I guess you have to start somewhere.

Now, this is far from my most advanced academic qualification, but the intriguing thing about this one is that it legally entitles me to supervise – and therefore take legal responsibility for – the public sale of what is undoubtedly a kind of drug. Without the licence, I can work under someone else’s supervision, but cannot just set up and flog booze on my own account. With it, and subject to a bunch of other constraints, I can do just that.

You can imagine that a fair proportion of the material, and the final test, focused around UK law relating to drink. There are obvious things to do with the age of the drinker, but I also learned that it is a specific legal offence to sell alcohol to someone who (in the considered opinion of the seller) is already drunk. Too much like shooting fish in a barrel, I suppose. Most of the laws fit around common sense, though as with any body of legal material you are left a little perplexed as to why specific conditions were imposed.

Russian troops and Finnish smugglers, 1853 (Vasily Hudiakov, WIki)
Russian troops and Finnish smugglers, 1853 (Vasily Hudiakov, WIki)

Anyway, all this set me thinking about law and qualification. The government of the day, however it was decided, has for a very long time indeed decided that it is entitled to a certain proportion of the profits from various kind of sales – and alcohol has typically been way up the list. And of course where rulers try to enforce a ruler, some subjects will concoct cunning schemes to get around the additional expense – excise duty spawns groups of smugglers almost by definition. But you only risk smuggling goods where the financial equation makes sense – small, easily concealed items where the tax duty is high enough that you can pocket a decent cut for yourself, while still leaving the buyer feeling they have done very well out of the deal.

So customs duties, and the body of regulations which underpin them, have been around for millennia. And – typically – part of those regulations consists of ways to appoint specific individuals as those few who are allowed to make transactions. In days of old, one suspects that many of these appointments were based on nepotism or bribery… if you had the right connections, or could stump up enough starting cash, you could find yourself in a comfortable position and set up for life. Nowadays the process is rather more transparent, and the barriers to entry are very much lower.

The Jolly Sailor, Bursledon (www.jollysailoroldbursledon.co.uk)
The Jolly Sailor, Bursledon (www.jollysailoroldbursledon.co.uk)

But equally, things have been tightened up in other ways. A couple of hundred years ago, it was fairly common for ex servicemen to use their prize money, or sign-off pay, or whatever they had saved up, to buy a little inn somewhere, and make a tidy living brewing or distilling booze of widely varying quality, and plying locals with the results. (Any pub you find called the Marquis of Granby recalls charitable donations by this 18th century gentleman who donated money to wounded servicemen). Provided you could afford a small building and a few bits and pieces to do the fermentation, you could set yourself up, no questions asked. These days, you have to go through hoops like planning permission, health and safety, police, plus of course getting a premises licence. There are all kinds of reasons why an apparently sound business plan might be rejected by officialdom.

The ISS (NASA/JPL)
The ISS (NASA/JPL)

So that is looking back… but what about forwards? Right now the only human outpost we have away from the Earth is the ISS. It’s not very far away – about 400km above the surface of the Earth, less than the distance from one end of England to the other. And I don’t suppose that the occupants have much privacy or opportunity to set up fermentation or a distillery up there. Though I did hear today that Budweiser has funded one of the science experiments on board, seeking to improve strains of barley with increased resistance to environmental stress. So maybe next year someone wil fund a experiment to make beer up there and see how yeasts behave in microgravity!

Alexa Far from the Spaceports logo
Alexa Far from the Spaceports logo

But let’s assume that within the next couple of decades we have an outpost or two somewhere else – the Moon, say, or Mars, or even a privately operated space station. How likely is it that nobody will attempt to ferment fruit or vegetable juices? And whose laws will be applied to regulate such an operation? Now run the scenario on a few more years, into the solar system I imagine for Far from the Spaceports and its sequels. There are a decent number of scattered habitats, each separated from the others by at least days, often weeks, and sometimes months of travel time. It will, I suspect, become impossible to try to enforce some kind of uniform system of laws.

Alexa Timing logo
Alexa Timing logo

My guess is that each habitat will have its own local set of laws and customs – no doubt broadly consistent with each other, but differing in detail. Sure, you can send a message anywhere in the solar system within a day at most, but if you get a tip-off that the habitat on Charon is bootlegging some kind of moonshine drink that is not allowed on the Moon, it’s going to take your police three or four months to trek out there and investigate. Will they bother? In that kind of situation, I don’t think it is feasible to try to maintain a single unified system of laws and regulations. So now suppose I have trained for my personal alcohol licence here on Earth (which in fact I did), and then decide on a whim to travel out to Charon. Will a publican out there recognise my licence? Or will he or she make me study for a duplicate one, ending up with a signature of someone on Charon rather than Earth? Right now, in the present day, it is extraordinarily hard to transfer qualifications between countries in professions like teaching, nursing, psychotherapy, and so on – will things be any different when we’re scattered across a few dozen habitats? I suspect not, especially as my own new licence doesn’t even allow me to do stuff in Scotland!

All of which is why I like writing about that near-future band of time, when there is no Federation, no Galactic Empire, or whatever – only local enforcement of issues according to moral and social principles which makes sense to the occupants. I suspect the chief coordinating factor would be economic – if you felt that some particular habitat was doing things the wrong way, you wouldn’t trade with them. They would become isolated, and there’s nowhere in the solar system away from Earth that can actually be self-sufficient. Hence I write about economic and financial crime, as these are the things that seriously threaten lives and livelihoods.

Compost

Mars from about 1000 miles, as seen by CubeSat MarCO-B (NASA/JPL)
Mars from about 1000 miles, as seen by CubeSat MarCO-B (NASA/JPL)

Before I start on compost, here’s a remarkable picture of Mars taken with a fairly ordinary camera, from a spaceship about the size of an average briefcase. Called a CubeSat, two of these were launched alongside the Mars Insight probe, and whistled past Mars while said probe made its way to a safe landing. More about Mars later…

It’s the time of year when – at least in the northern hemisphere – you put compost on your garden as part of bedding it down for the winter. These days that’s generally easy – you trot along to your local garden centre and get 3 bags for £12, or whatever the deal is, and you spend a suitable amount of time distributing it around your little patch. Someone else has done most of the hard work of transforming original plant and animal matter into an easy-to-use commodity.

But in a big garden you can do things a bit differently (and if you’re a farmer, you’ll be up into another league altogether, which I am not going to presume to write about). You can gather up said plant and animal matter yourself, stow it away somewhere dark and warm, add whatever extra bits and pieces you want, wait the better part of a year… and there you have your own compost. Which is what has been happening up here in Grasmere – last year’s rotted stuff, including pig manure, was ready for distribution. Not only that, but all those leaves which have been building up in the garden got put into the compost bins, waiting for their turn next year!

Now, this process has been going on pretty much ever since people discovered how to cultivate crops. Last year’s plant waste, together with stuff from whatever animals you had, and most likely human waste as well, got stashed away and spread on the fields when ready. The process has got steadily more scientific over the years, with additives to ensure that the ratios of chemicals are appropriate for the crops in question, but fundamentally nothing has changed.

Plants about to be harvested on the ISS (NASA/JPL)
Plants about to be harvested on the ISS (NASA/JPL)

But now think about what happens when you go out into space. You can grow some crops hydroponically, but this needs water which has been prepared with suitable levels of nutrients… which needs those nutrients to be available. We’ve done it up on the ISS, where the astronauts have prepared bits and pieces of salad to accompany their regular rations. But most of what is eaten in orbit has had to be carried there in a cargo supply ship. Suppose we add a couple of large modules on to the ISS and start growing things on a bigger scale. Then maybe we just need to ship the nutrients up there. That helps.

Now go a bit further. You have built a moonbase, or are living in a dome on Mars, and you want to grow your own stuff. In one sense you are surrounded by soil, but it is totally lifeless soil. It probably has a number of the basic chemicals you need, but none of the complex organic substances that your plants need. So you’re back to shipped-in nutrients… until you have either built up some human waste (and allowed it to decompose in some suitable way), or waited a year for the spare bits and pieces from one year’s harvest to rot down into compost.

Cover - The Martian (Goodreads)
Cover – The Martian (Goodreads)

This is probably reminding you of The Martian – Mark Watney manages to grow potatoes using the left-behind waste of his fellow crew-members. It goes pretty well until an accident exposes all his carefully prepared plants and compost to sub-zero temperatures and an air pressure less than that on Everest… which kills the lot and causes him to revert to Plan B (or probably, Plan F by that stage in the book). All necessary stuff, and emphasising the point that to grow Earth plants, you have to have built up a stock of Earth compost to encourage their growth.

So as I was piling leaves into the compost houses to being their long process of rotting down for this time next year, I suddenly wondered about our future. Out of all the unlikely cargos to be shipped out to our future colonies out on the Moon, Mars, the asteroids, and wherever else, wouldn’t it be supremely funny if most of them were shipping out the raw ingredients to make compost? Not an eventuality that makes its way into fiction very much… but how else are you going to grow your food?

The Compost Houses sitting waiting for next year
The Compost Houses sitting waiting for next year

Fire

The empty fireplace
The empty fireplace

This week I helped swap over an old wood-burning stove for a new one. As has been my experience of all practical jobs, what had promised to be a fairly straightforward out-with-the-old-and-in-with-the-new process ended up having unexpected wrinkles. The chimney pot also needed replacing (since the old fire didn’t draw very well), and a new chimney liner had to be put in. And there was an old liner which had to be pulled out – both liners follow a chimney which is about ten or eleven metres high, so these were interesting tasks in themselves.

The new fire installed
The new fire installed

Then an old hearth had to be taken out (which has already happened in the picture above, thanks to the very large drill on the floor, plus a sledgehammer and other hefty tools). Then the new stove had to be moved into position and the exit pipe fastened to the chimney liner with suitable gunk.

Then the paintwork had to be touched up where it had been bashed about by all this. And finally the copious amounts of dust – from stone, soot, brick and ash – had to be cleaned up on pretty much every surface in the room!

The story has a happy ending – the new fire really does light, as you’ll see below, and early impressions are that it is doing a better job than the old one. But while doing this job, I had plenty of time to contemplate fire. Or more widely, energy.

There are some places on planet Earth where people can live without using any energy source for heating, though most places need something at least in wintertime. But every society that I know of, world-wide, has harnessed fire for cooking. This isn’t just for aesthetic or culinary satisfaction – the process of cooking food makes a much wider range of nutrients accessible to our digestive system in much more reliable quantities. So the harnessing of fire for cooking – something like a couple of million years ago, give or take – liberated our hominid ancestors to get on with other things rather than have to forage endlessly. They could prepare food so as to use it more efficiently, and store it so as to survive lean times.

The Venus of Willendorf, c. 30000 years BCE (Wiki)
The Venus of Willendorf, c. 30000 years BCE (Wiki)

They could invent fish hooks and jewellery in their spare time, create artwork and conduct sacred ceremonies. (They also designed weapons of increasing effectiveness, and social orders which exaggerated differences in wealth between individuals, but we’ll skip over that for today). The use of fire for cooking seems to coincide with one of those great leaps forward in the often-slow process of human development, signalling this opportunity for our remote ancestors to explore and comprehend their world with intelligence.

Cover - In a Milk and Honeyed Land
Cover – In a Milk and Honeyed Land

All this happened in remote prehistory – long before the Late Bronze Age of In a Milk and Honeyed Land and its sequels, and long before the Langdale world where Quarry will be mainly set. By those times, fire and cooking were established parts of life whose origins were lost in the unfathomable world of the ancestors. But fire – energy – has remained a key part of our expanding world. Our ability to inhabit every part of the world has relied totally on our ability to maintain adequate warmth in our houses. An unprotected human in the middle of an Antarctic winter wind would die within thirty minutes at most, and would be crippled long before that.

A wood-burning stove is basically a very old bit of technology – except the one I helped with was made of metal, which pushes the date much more recent. But the problem it is helping to solve is perennial. Nowadays we don’t actually need to burn wood to generate heat, though many people find the experience of being warmed by an actual fire to be more comforting and engaging than just switching on a radiator. Energy from many sources is fed into our electricity grid – coal, water, wind, oil, nuclear, solar – and whatever the source, it runs an electric fire very nicely. The choice of our national energy spectrum of sources is – and should be – made according to national and global considerations, not whether I personally happen to have one device or another.

Artist's impression, Juno probe near Jupiter (NASA/JPL)
Artist’s impression, Juno probe near Jupiter (NASA/JPL)

And the situation become more stark as we go out into space. Space, as well as being mind-bogglingly big – is a weird place. In one sense it is freezing cold – a warm body will radiate away energy at a steady rate. But in another sense it is full of energy – light from the sun, electromagnetic radiation, and down at a quantum level a whole sea of vibrant energy just waiting to be collected. Whether we send out a robotic probe like Dawn, or we go elsewhere in person, we either take our energy with us or we collect it from the void around. The Juno probe has huge solar power collectors – each of those three panels in the picture is about the height of a typical house – and it is operating  almost at the outer limit of where such solar panels can be used. Probes that go further from the sun must carry their energy with them, and when it runs out they will die.

Cover, Tau Zero by Poul Anderson (Goodreads)
Cover, Tau Zero by Poul Anderson (Goodreads)

Most science fiction writers assume that the spaceships that they write about can refuel somewhere in space – maybe by gathering up interstellar hydrogen as they travel about using one variation or another of an idea of the physicist Robert Bussard – Poul Anderson’s Tau Zero was a relatively early novel making use of a Bussard ramjet, and at some stage Star Trek script writers decided that this was how the Enterprise and other similar ships gathered fuel (alongside matter-antimatter reactions and dilithium crystals). That way your ship can carry on boldly going without the inconvenience of having to stop at a nearby starbase just to load fuel into the necessary bunkers.

However it’s done, people will continue to need energy – fire – wherever they go. I think it’s most unlikely that energy sources in my science fiction books look anything like a wood-burning stove, but whatever they do look like, they serve the same purpose.

The new wood-burner alight
The new wood-burner alight

Mars Insight lander and Elysium Planitia

A quick post today as I have been buried deep in coding web applications for Lake View Country House and its sister businesses. As an added bonus there will be an extract, this time from Timing.

Artist's impression, Insight on Mars (NASA/JPL)
Artist’s impression, Insight on Mars (NASA/JPL)

First though, the NASA Mars Insight lander. This is well on its way to Mars, and is due to touch down on November 26th (at around 3pm Eastern Time, or 8pm UK time). Landing on Mars has traditionally been a hazardous affair, and something like half of all probes sent there have not done so successfully. But things have improved recently, so let’s hope all goes well on 26th.

Now, Insight has a couple of primary science targets, both relating to the interior of the planet. One instrument will measure heat flow under the surface, and another will detect seismic changes – earthquakes if you like, though perhaps Marsquakes might be a better word. The overall intention is to get a better idea of what Mars is like once you probe below the dusty surface. To that end, various drills will work their way several metres down below wherever the probe ends up landing.

The site area on Elysium Planitia chosen for landing (NASA/JPL)
The site area on Elysium Planitia chosen for landing (NASA/JPL)

But it was the landing place that particularly caught my eye – a flat plain called Elysium Planitia, roughly straddling the equator. This was chosen for scientific reasons – it is mostly flat and has a suitable kind of surface layer for the instruments to work well. But interestingly, Elysium Planitia features in Timing (Far from the Spaceports Book 2) as the site for a developed, and particularly lively, habitat.

In that book, Mit and Slate visit a couple of places on Mars, as well as its tiny moon Phobos. Their first target is a training college close to the mountain Olympus Mons, and from there they move across to Elysium Planitia in order to meet an old adversary… who claims now to be an ally. The two sites are in stark contrast – the training college is austere and frankly dull (though helpful for Mit and Slate in deducing what has been happening), but Elysium Planitia is exciting to the point of excess… Insight will have a very staid experience in comparison…


The quayside at Elysium Planitia was busy and bustling, and didn’t exactly feel safe. I kept all my pockets sealed shut, held my bag in front of me all the time, and tried to stay alert. Slate had promised to keep a eye out for anybody trying to infiltrate at a virtual level. I was used to crowds in London, but they were well-behaved, in which individuals knew where they were going, and made a habit of slipping past each other without interaction. And, as Slate kept reminding me, I had been away from that environment for a considerable time now, and the various habitats I had visited more recently were comparatively empty. I was out of practice.

Here, there was a lot of intrusion into personal space. Men and women jostled past each other, and there was a sensory bombardment on every side, offering all kinds of goods and services. Nothing was free, and the price of the more personal interactions was, literally, astronomical.

The habitat was much the biggest one I had been to, making even the south lunar pole settlement look small. I focused on threading my way through the hustle, following Slate’s internal prompts for some distance from the dock towards a quieter, cheaper row of guest houses. All I wanted – all that Elias would expense for – was an economical, no-frills hideaway. All being well, I would be back to Phobos soon.

The place I selected had no human greeters, just an automated checkin service. I wasn’t paying enough to warrant a real person’s presence. Out in space, Slate had sighed about the frequent partings our job required. I was much more basic in my needs, and this was my complaint. I particularly loathed the need to keep staying in dingy soulless rooms.

My heart sank slightly when the welcome screen spiralled brightly coloured words at me: “We’re Like Vegas Used To Be! Only In Space! And Better!!” But the process of getting access to the room was easy to follow, and it didn’t take long. You just had to focus away from the vivid ads which pressed in from the edge of the screen just as soon as the system had decided that I was an adult.

Once I had successfully navigated that, I was given access to the room. It was secure and reasonably comfortable, and it got me off the streets well before the really busy evening time. I had no particular desire to just go wandering round in a fit of exploration. There was going to be quite enough excitement just meeting Jocasta tomorrow.

 

Dawn, death, and ion drives

Dawn takes off, September 27th 2007 (KSC/NASA)
Dawn takes off, September 27th 2007 (KSC/NASA)

Last week, NASA’s Dawn space probe, which first launched back in 2007, finally ran out of fuel and has been declared dead. Regular readers will know that Dawn has been a great source of information and inspiration for me as I have been creating the future world of Far from the Spaceports, Timing, and the in-progress The Liminal Zone. So it seemed fitting to me to do a kind of tribute to Dawn here.

So here’s a timeline of key events:

  • September 2007 — Launch
  • February 2009 — Mars Gravity Assist
  • July 2011 — Vesta Arrival
  • September 2012 — Vesta Departure
  • March 2015 — Ceres Arrival
  • June 2016 — End of prime mission
  • July 2016 — Start of first extension
  • November 2017 — Start of second extension
  • November 2018 — No remaining fuel: mission ends
Enhanced colour image of Ceres (NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)
Enhanced colour image of Ceres (NASA/JPL-Caltech/UCLA/MPS/DLR/IDA)

Of course, Dawn is not going anywhere – it will remain in its current orbit around Ceres for decades at least, until some combination of inevitable gravitational perturbations distorts that orbit enough that it eventually crashes into the surface. But there will be no more navigation from Dawn, no more course correction, no more photos or science information.

I want to talk a bit about Dawn’s ion drive, in the connection of storytelling, but if you want pictures and information about the mission findings, the best place to start is the NASA site, which has separate pages for Vesta and Ceres.

So, the ion drive. Most craft up to now have used chemical rockets – two or more chemicals are stored separately, then mixed to form a high-energy burst of propulsion. For example, the latest SpaceX SuperDraco engine uses the two liquids nitrogen tetroxide and Monomethylhydrazine. The net effect is that the spacecraft is pushed with high acceleration in a particular direction. After this engine burn, the craft coasts with no further propulsion for days or months, until it’s time for another correction. Astronauts in the craft have to endure short periods of high g-forces, followed by long periods of weightlessness. The engine burns have to be very precisely calculated for direction, force, and duration, so as to minimise the need for subsequent burns. Once the fuel is gone, it’s gone, and each burn takes a fair proportion of the fuel stores.

Falcon Heavy launch, February 6th 2018 (SpaceX via Wikipedia)
Falcon Heavy launch, February 6th 2018 (SpaceX via Wikipedia)

What does this mean for storytelling? Well, most of the journey is spent at zero acceleration, coasting towards your destination without burning fuel, and without any sense of up or down. It took the Apollo astronauts about three days to get from the Earth to the Moon (and the same back again, after doing stuff on the lunar surface). As and when SpaceX or whoever sends another rocket there, it will still take about three days – the time taken is a result of the coasting period without power, not the force of the engine. And because of the long zero-gravity sections, you need to be fairly well-trained to manage this.

SpaceX 'Starman' orbit (SpaceX Twitter feed)
SpaceX ‘Starman’ orbit (SpaceX Twitter feed)

Now consider a trip to Mars. In February of this year, SpaceX launched a Falcon Heavy rocket, with payload of a Tesla car and suitable contents. It left Earth orbit and headed out on an orbit that goes out past Mars, but at a slight angle so that the two never intersect. Each orbit takes 557 days to complete, so at this point not even one has been finished. The payload – a Tesla car – passed by Mars orbit a few days ago, after about eight months.

The Hermes rocket from the film The Martian (http://the-martian.wikia.com)
The Hermes rocket from the film The Martian (http://the-martian.wikia.com)

Now, this rocket had not reserved enough fuel to slow down and enter Mars orbit – it was a vivid proof of concept for SpaceX, not a real attempt to land on the Red Planet. But basically, if a human crew does the same journey in the same rocket, it will take them about eight months to get there – eight months of zero gravity, unless rocket design changes to include a kind of pseudo-gravity produced by rotation, as in the Hermes spacecraft in The Martian.

Getting out into the solar system on chemical rockets just prolongs these figures. Potential astronauts have to cope with months, if not years, of isolation and low gravity. It is just not viable to send people there, which is why the present focus has been on sending hardware and instruments.

Schematic diagram of ion drive (NASA/JPL)
Schematic diagram of ion drive (NASA/JPL)

Enter the ion drive, as used on Dawn and a handful of other craft. It is, in some ways, the opposite of a chemical rocket. It produces small amounts of drive thrust continuously for a very long time. NASA estimates that the thrust of the engines on Dawn is roughly the same as what you feel when you hold a piece of paper on the palm of your hand. It’s quite useless for getting off the Earth’s surface – you really do need something powerful for that – but as a way to get you from Earth to Vesta… or Vesta to Ceres… From a standing start in free space, Dawn would take about four days to go from 0 to 60 mph. But that ion drive just keeps piling on speed. Dawn’s engine ran for a total of about 2000 days during the mission – over 5 years.

Artist's impression, Dawn at Ceres (NASA/JPL)
Artist’s impression, Dawn at Ceres (NASA/JPL)

Now, if you have an engine that is always-on, your whole picture of the solar system changes. Let’s suppose you keep accelerating to the mid point, then flip over and decelerate the rest of the way, so that you get to feel a constant gravity all the way. Then further is more efficient. In twice the time you can go four times the distance. Or, to put the same thing another way, to go twice the distance takes less than one and a half times the time.

Of course, Dawn’s motors were still early versions of the design, with a low thrust output even at maximum. For my stories, I’ve assumed that the design can be enhanced to give an acceleration equivalent to 1/20 of that at Earth’s surface – considerably less than what you get on the moon. It would take some getting used to, but it means that your body and brain have a clear sense of up and down, and all those physiological functions that need gravity have a good chance to keep going! What does this mean for travel time?

  • Earth to Mars takes between ten and twenty days, depending on their relative position at the time of launch
  • Earth to Ceres takes about 3 weeks
  • Earth to Pluto takes about three months
Timing Kindle cover
Timing Kindle cover

That works for storytelling – it’s not very different from journeys that people would take by sail back in the day. For example, an 18th century trip from England to India would take something like four to six months. Once the Suez canal was open, this reduced to about two months. People will put up with a journey like that for all kinds of reasons. So that’s roughly how you can imagine the solar system of my science fiction novels – a bit like our world was in the days of sail and early steam ships.

Here’s a short extract from Timing, in which journey time gets discussed a bit. Meanwhile, RIP Dawn!

Then, quite suddenly, I had been sent all the way to the Jovian system. That would have been fair enough after the local jobs, but it turned out to be a false alarm. One of the analysts thought he had seen a recurrence of an old scam, running out of the Callisto hub. So off we had gone – a long journey for both Slate and I, and when we left Earth orbit the planetary alignment meant there were no friendly stopovers to break the journey.

Once we got there, the two of us had poked around, wormed our way into this module and that, but found nothing. To be sure, we confirmed that the reported irregularities were real. We had easily managed to find the batch runs where the credit had gone missing, by comparing input and output. It happened every time a specific input value was missing or unreadable, and a default value had to be assumed. But the chosen default looked right and we couldn’t find root cause. The code was non-standard, and frustratingly weird, but there was nothing obviously suspicious. The logs were so skimpy as to be almost useless. It did not seem to be the kind of task that needed our skills, nor to be as much of a problem as the analyst had first thought.

When it was over, and having drawn a blank, we sent a summary report down to the Finsbury Circus office, suggesting that perhaps it would be more effective to send an accountant. We had managed to get four weeks out of the work, but it still felt like a long drag for not much return. To be fair, it was unusual for the analysts to make a mistake like that, so I was professionally polite rather than curt. Then it was time to warm up the engines of our sloop, the Harbour Porpoise, and off we set on the homeward leg.

I was all set for a boring journey back down the gravity hill to Earth, but Slate found an orbital option which would take us right past the Scilly Isles. That settled it. We deserved a reward for our fruitless diligence. So we changed the navigation plan, sent some messages ahead, and here we were. Elias, my manager back in London, had made a token protest at the diversion, but I told him that the Harbour Porpoise needed servicing and the delay was unavoidable.

Anyway, a couple of hours signal lag meant that we were already en route by the time his answer came back. We just said that we didn’t have enough reaction mass for such a radical course change. It might even have been true, though I was careful not to ask Slate for a technical analysis, and she was just as careful not to offer one.

Regardless of that, we weren’t minded to listen. Slate and I both reckoned that we deserved the break. Six weeks of voyage out to Callisto, and four weeks of fairly dull work had not made us receptive to a tedious trip straight back home again. It would mean nearly three months’ travel time for just one month of work, and we weren’t about to just put up with that without an argument.

Tesla Starman (SpaceX Twitter feed)
Tesla Starman (SpaceX Twitter feed)

Ultima Thule

Today’s blog is focused on the next target of the New Horizons probe, which back in July 2015 sent back such remarkable pictures of Pluto and Charon. But before that, here’s a quick reminder of this week’s Kindle Countdown deals for Far from the Spaceports and Timing – £0.99 / $0.99 for the next couple of days. Follow these links…

New Horizons route, including Pluto and Ultima Thule (Wiki)
New Horizons route, including Pluto and Ultima Thule (Wiki)

Right. New Horizons. After the Pluto flyby, the natural question was, what next? There was enough fuel and energy reserves to consider a small course change… but to what end? Pluto is at the inside edge of the Kuiper Belt, a tenuous and very sparsely populated volume of space. Over the last few years, we have been steadily gaining information about some of the contents, many of which have hugely elongated orbits. The big prize out there is the possibility of a really sizeable planet, acting as a gravitational shepherd to coax the smaller bodies into resonant patterns.

Planet 9 has not yet been found, but several smaller bodies have. And one of them, catalogue number KBO 2014 MU69 , happened to be well placed for New Horizons. So, an appropriate course change was made as Pluto dwindled into the distance, and KBO 2014 MU69 – now provisionally renamed Ultima Thule – became the next goal.

Current New Horizons view of Ultima Thule (NASA/JHUAPL/SwRI)
Current New Horizons view of Ultima Thule (small dot on right-hand frame) (NASA/JHUAPL/SwRI)

But distances out in the Kuiper Belt are large, so there has been a considerable wait. Ultima Thule is about 12% further away from Earth as Pluto is. The actual flyby will occur on January 1st next year, and at this stage we still don’t really know what to expect. The Hubble telescope orbiting Earth shows Ultima Thule as just a slowly moving point of light. New Horizons is about 33 million miles away from it – about 1/3 the Earth-Sun distance – and still can’t resolve it to more than just a point source. We cannot make out any surface detail. We don’t know if it’s roughly spherical, or irregular, or even a little cluster of fragments all moving together. Just about all we know is that it’s less than 40 km across, and although very dark by the standards we are used to in the inner system, is slightly more reflective than expected.

Artist's impression, New Horizons and Ultima Thule (Steve Gribben/NASA/JHUAPL/SwRI)
Artist’s impression, New Horizons and Ultima Thule (Steve Gribben/NASA/JHUAPL/SwRI)

After sending the Pluto and Charon data home, New Horizons went to sleep for a couple of years, with a wake-up call in June for some of the instruments and a course correction. It is now being prepared as best we can for the encounter. It’s a fascinating problem – light or radio signals take around 6 hours to cross the gulf between us and the probe, so there is no possibility of direct control.  Any reply takes another 6 hours to get back. The systems have to be set up in advance, according to our best guess of what will be there. The final course changes will occur in mid December, when the ground crew wil decide just how close to steer towards Ultima Thule. In one sense, the nearer the better… but the higher the risk that the probe will make brief, catastrophic contact with some fragment of rock and ice. On the day, the probe will whistle by at over 30000 km/h, so there’s no opportunity for second chances. Whatever sequence has been set up in advance, will be played out without modifications. After that, New Horizons will spend the better part of two years streaming the data back to Earth. So although the rendezvous will be a New Year treat, we shall have to wait a long time until we get any high-resolution images or other data.

As yet I haven’t written about what life might be like in a suitably protected environment out in the Kuiper Belt… maybe this encounter will be the seed of another book, in the way that the flyby past Pluto and Charon has contributed to The Liminal Zone. And here, just for a bit of fun, are someone’s first impressions of the settlement on Charon, extracted from the early sections of The Liminal Zone

Nina walked steadily along the winding curves of Lethe towards Asphodel. The house AI had finally told her where Lance’s quarters were situated in Acheron, and had transferred directions onto a hand-held to direct her there. From space, the overall shape of the Charon settlement had been clear – five sinuous linear habitats, following curves in the underlying terrain and joined radially to Asphodel. When you were actually down here, it wasn’t nearly so neatly divided. There were extra little corridors and alcoves which broke up the superficial symmetry, and little tunnels that dived underground and then resurfaced at unexpected places. She was glad that the little hand-held router buzzed faintly at junctions to tell her which way to turn.

Changes… and Kindle Countdown deals

A short post this week, mainly consisting of two extracts, one each from Far from the Spaceports and Timing. These are both on Kindle Countdown deals from this Friday, October 26th, for one week, price set at £0.99 / $0.99 depending which side of the Atlantic you’re on. More of that later… here are the extracts.

The main characters are Mitnash (Mit) and his AI persona partner Slate. in this extract, Mit and Slate are recovering from a difficult episode in which Slate was hacked by a shady individual known as The Wise Man…

Far from the Spaceports (follow this link)


Far from the Spaceports cover
Far from the Spaceports cover

“Slate, how much do I talk to you without knowing it?”
She was amused.
“All the time, Mit. You murmur to yourself while you’re thinking, and you subvocalise throughout the day. There’s very little about your thought life I don’t know. Or your fantasy life. You’re whispering to me almost all the time.”
I sat back, bouncing a little as I forgot to adjust the move for the low gravity.
“Oh.”
“It’s nice. I like it. It makes me feel very intimately connected with you. Why? Does it worry you?”
“Not with you, no. If I can’t trust you, I might as well give up now. But I suppose that means you know all sorts of things that I have never told Shayna.”
I considered that soberly, while she was tactfully not replying. It was definitely something to think through on another occasion.
“But anyway, when the hand-held had been compromised, and that other thing was quizzing me, I started to wonder how much I was giving away. Or how much the Wise Man was learning without me knowing.”
“While you were in his quarters, he would have had a direct link from the hand-held into his main system. It was a very old model Ziggurat, like I said before, not very responsive at all. Male gendered, but only just. Badly set up and very poorly programmed. But he has the name Hunn Gravfelt, which at least shows that one of them has read a few decent books. Very arty. But anyway, once you left there, he had no way of querying the hand-held until you got linked up to a ground system. He’s a shady character, but not a very competent one.”
“I suppose the big question is how much information he now has.”
“Yes. But actually, we don’t know for sure what he was able to derive while you were on Agnes. We deliberately left a lot of material out in the open, so he would find it easily enough. We now have to wait and see where that turns up. Like the breadcrumbs in the old children’s stories.”
“But he doesn’t know anything I said on the way home?”
“No. There was a very large data packet all ready to be sent back, but it was never buffered. Do you want to know what was in it?”
I stayed silent and thought about it for a long time, and Slate stayed silent with me.
“Don’t tell me the details. But do run through it again, and tell me if I was about to give away anything critical to the job. Or that might have put Shayna at risk.”
There was a very short pause.
“Nothing like that. If Yul Yulsson was a voyeur, and if he’d ever received it, he could have had some fun with it, for sure. But he would not have learned anything of real value. There’s actually more about me in the packet than Shayna.”
“Hmm. Best not to tell her that, if you don’t mind.”
“This can be our secret.”
I moved to the cabin, pulled out some of the new pieces of clothing which, so far as I could tell, would help me fit in at the Frag Rockers bar a lot better than the formal garb I had worn to see the Wise Man.
“Slate, who’s leading at Frag Rockers tomorrow?”
“A prog rock fusion band called The Descenters. The keyboard player and drummer are locals, from St Martins and Tresco respectively, and the rest are from Ceres. They have a very big fan book on SystemPlus. They’re best known for extremely long concept gigs. They lost their way a bit with Trails on Topological Notions – the twenty-eight minute triangle solo called Geodesics confused even their best fans. But then the electro-gamba player left, and they built up their reputation again.”
“Will I like them?”


Next up, in another book, Mit is discussing a recent shipwreck with his friend Parvati…

Timing (follow this link)


Timing Kindle cover
Timing Kindle cover

I wanted human company again, so I stretched and went in search of Parvati. She was brewing chai as I wandered in to the kitchen. Seeing me, she doubled up the amounts, found a second mug, and arranged some savoury crackers and a red and yellow striped cake on a tray.
“Did you and Slate get anywhere?”
I shook my head.
“Total blank. The figures don’t tell us any more than the basic alert message we got from Finsbury, and they won’t let us access the code yet. There’s almost nothing we can do until we get there.”
We moved back to the bridge and enjoyed the snack together.
“Chandrika just picked up the latest from the wreck site for Selif’s ship, if you’re interested?”
I very definitely was interested. We finished the crackers, and she sliced two generous portions of the cake.
“They’ve made available the results from the data recorders. There’s nothing at all unusual until about three minutes before the crash. At that point, Selif took the vessel’s riding lights offline and uploaded an amendment to the nav plan.”
“Presumably to avoid being identified by the duty porters?”
“Most likely, yes. You’re not supposed to disengage them, but people do. As you say, he was motivated to slip in without attracting attention. It’s also uncommon to amend the plan at that late stage, but it happens. Anyway, the upload was completed successfully, taking only the expected lag. Except that a couple of seconds later, both recording devices ceased gathering data. At the same instant. That is unheard of.”
I looked at her.
“How did that happen?”
“The maintenance log for the recorders showed that Selif had skipped two routine services. So they highlighted that in the report, and almost immediately the manufacturer put out advisory notices basically denying all responsibility if people ignore the recommended schedule. So the official version simply lists an open verdict.”
“Is there an unofficial version?”
She grinned.
“Of course. Chandrika, why don’t you tell them?”
“To be sure. I heard this from one of the personas on Martin’s. He works part-time with a man who’s an expert on the embedded systems in boat engines.”
I nodded. It was a highly specialised area, and one that I knew next to nothing about. But it made sense that a man with those skills would have an opinion on data recorders.
“Well, he said two things. One is that a full restart cycle for those boxes is about half a second longer than the time from the point of failure up until the impact on Teän. And the second thing is that there are only two known exploits for that model of recorder which could bring down both boxes together. One of them cannot possibly have anything to do with this case: a different ship configuration altogether. The other one happens to rely on a routing plan change.”
I sat there, absorbing the news. It made sense that these units would go into an automatic reboot mode if they went dark for some reason. Normally that would restore them to full operation in plenty of time to carry on doing their job. But in this case, the boat had hit Teän before they had started up again. I stirred in my seat, but Slate beat me to it.
“That’s very precise timing on someone’s part. Does anybody think it is just a coincidence?”
“Oh, Slate, the official verdict is open. Nobody is suggesting anything.”
We all laughed together.
“Either it was phenomenally bad luck on their part, or…”
I paused, and Parvati continued.
“Or else someone wanted rid of them, and found a clever way to do it.”


Why the Countdown deals? Well, the last day of October marks the last day of my current job in London. I shall be opening a new phase of working life up in Cumbria. Expect more posts about life up there.

So it seemed fitting to post some extracts, and to discount on Kindle, my science fiction series where coding, AI, and financial fraud in space are the main themes.

But I’m not saying goodbye to that style of writing! As regular readers will know, The Liminal Zone shares a lot in common with those books, though it has a different focus and is set a couple of decades further in the future. And behind that, the third in the Spaceports series is toddling along, tentatively named The Authentication Key at present.

Next week’s post will still be from London, but the one after that will be from Grasmere. And don’t forget… there’s a week of Countdown deal on each of Far from the Spaceports and Timing!

Invasion, migration and assimilation

Cover - 1066 and All That (Goodreads)
Cover – 1066 and All That (Goodreads)

Last weekend, a whole bunch of people, including a number of my online friends, have been remembering and reenacting the events surrounding the Battle of Hastings – 1066 and All That. It so happens that everyone I know who was at Hastings the other day favoured the Saxon side, from which perspective Harold is a fallen hero, who came so close to repelling the invaders in the south as well as the north. But I suppose that a great many of the participants took the Norman side, and so found themselves once again victorious.

In fact, most people I know prefer the Saxons, and harbour a deep-seated wish that things had gone differently. Perhaps this comes from a desire to cheer on the underdog, or from hearing about how viciously the Normans set about securing the land they had claimed (especially in the north). But I suspect it is also because we were brought up on tales of Robin Hood and his Merrie Men, striving as disenfranchised and downtrodden Saxons against their wicked and uncouth Norman overlords.

Hastings reenactment 2016 (Getty images via BBC)
Hastings reenactment 2016 (Getty images via BBC)

I have to admit that, personally, I struggle to see the Saxons as unequivocally the nice guys in our history. My own historical preference is earlier, often swimming in the uncertainty and veiled mystery of times before the written word gave us its particular perspective. And from my view, the Saxons (and Angles, etc) are new arrivals who themselves had claimed a new land by often violent methods. The tales of Arthur and his Companions, stripped of their courtly Medieval topcoat, tell us of a time when British and Welsh leaders tried to protect their homes from wave after wave of incoming aggressors.

Statue King Arthur at Tintagel (Trip Advisor)
Statue King Arthur at Tintagel (Trip Advisor)

Ultimately their stand was a failure – from south to north the Saxons defeated and occupied British land, and the points of resistance were only sandcastles in a rising tide. Perhaps the last to fall was Dunmail, in what we now call Cumbria. As this last king of the British lost his last battle, his last few loyal men took his crown and cast it into Grizedale Tarn, so the new usurper would not have the satisfaction of claiming it. Like Arthur, the promise is that Dunmail will – one day – arise again to claim his crown and kingdom.

Grizedale Tarn from Dollywaggon
Grizedale Tarn from Dollywaggon

So – making what I suspect are controversial statements – I kind of feel that there was something karmic in the events of 1066. The Saxons had arrived and pushed aside the earlier occupants, and now something very similar was happening to them.

Now, arrivals into a country are a curious thing. It’s worth thinking about how we reconstruct what happened. In the past we have had to rely on written perspectives, often put down on paper, papyrus, or clay many years later by the winners or their ancestors. Or we look at archaeological remains, which by their nature can only say so much about their owners. Did the same culture adopt new artefacts quite suddenly? Or did a new culture simply reuse the same things as their predecessors? Nowadays we can have a bit more insight from DNA testing, and the outcome of this has sometimes supported and sometimes challenged prior expectation. More of that later.

DNA map of Great Britain (University of Oxford via The Independent)
DNA map of Great Britain (University of Oxford via The Independent)

There are basically two ways that new arrivals interact with those people already there. Sometimes there is violent displacement of the old by the new. This seems to have happened in Bronze Age Britain, where there is hardly any genetic continuity between the Beaker People and their Neolithic precursors – the great stone monument builders have left almost nothing of their genetics throughout most of Britain. This DNA result rather overturned the prior thinking that the change represented a peaceful transfer of ideas.

Other times the old and new quietly absorb each other and are enriched by the process, playing out on a national or regional level the process of human reproduction, with all its delights and difficulties. Newcomers might arrive for all kinds of reasons, martial or peaceful, but after a few years one finds a fusion of the two emerging – a child of both originals.

A beaker of the Beaker People (Natural HIstory Museum)
A beaker of the Beaker People (Natural HIstory Museum)

Now, at the time of arrival, nobody knows what will happen, and it’s natural for the current inhabitants to fear and deride the incoming hoard. So the Saxons did to the Normans.. so the Britons did to the Saxons… so the Neoliths did to the Beaker People… and no doubt so the Neanderthals did to the Homo Sapiens clans. We still see this played out today, as nationalist politics finds innovative ways to arouse anxiety about “the other”. They’ll take our jobs… they’ll impose their religion… they’re not like us… slogans about “the other” can be found in pretty much every part of our world, fuelled by migrations and flights from war and famine. Personally I remain optimistic, and look for the creative fusion of cultures rather than the catastrophic collision. But looking back at history, it takes effort to find creativity, and we humans don’t always manage it.

Going back to DNA, there are still limitations. We can now – tentatively, and extrapolating from individual cases – identify where intercourse has combined the heredity of two cultures. So we know that the DNA map of Britain correlates pretty well with some historical events, and not with others. We know that pretty much all humans outside Africa have a significant percentage of Neanderthal DNA. We know that a teenage girl’s finger from Siberia shows her to be the child of one Neanderthal parent and one Denisovan parent, some 90,000 years ago. But what we don’t know is the circumstances of the intercourse. Was it a socially sanctioned event, even a personally consenting one? Or was it something darker, the result of forced prostitution or rape? DNA cannot tell us, but that’s the kind of detail we would like in order to uncover the interactions of peoples. It’s one of the great anxieties of mankind – do the newcomers arrive in peace or war?

Siberian cave where the girl's finger was found (Bence Viola/Max Planck Institute for Evolutionary Anthropology)
Siberian cave where the girl’s finger was found (Bence Viola/Max Planck Institute for Evolutionary Anthropology)

Writing, both historical and speculative