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Science news: a “new,” safe, clean nuclear tech that’s actually decades old!

February 27, 2019 1 comment

It’s been a while since I did a science-themed post around here, partly because of generally neglecting my blog but partly because I’ve fallen out of the habit of reading science magazines online — something that I fear has been affecting my professional writing as well, since I’ve been having trouble thinking up new story ideas in recent years, and maybe the lack of inspiration from science articles is part of the problem. But recently, when the Firefox browser discontinued its inbuilt support for RSS feeds, I found a separate add-on that worked even better, in that it notified me of new posts and made it easier to keep current. So I decided to take advantage of that to subscribe to some science sites’ feeds so I could stay more current with the news.

Anyway, Discover Magazine just posted the following article, which is quite interesting:

Nuclear Technology Abandoned Decades Ago Might Give Us Safer, Smaller Reactors

It’s a long article rather than the short colums the feed usually gives me, so I’m not sure if it’ll stay permanently available or go behind a paywall at some point. So I’ll summarize here.

It turns out that, in the early days of nuclear research, scientists had examined various options for generating power from atomic fission, including a system called a molten salt reactor. Per the article:

Every other reactor design in history had used fuel that’s solid, not liquid. This thing was basically a pot of hot nuclear soup. The recipe called for taking a mix of salts — compounds whose molecules are held together electrostatically, the way sodium and chloride ions are in table salt — and heating them up until they melted. This gave you a clear, hot liquid that was about the consistency of water. Then you stirred in a salt such as uranium tetrafluoride, which produced a lovely green tint, and let the uranium undergo nuclear fission right there in the melt — a reaction that would not only keep the salts nice and hot, but could power a city or two besides.

Weird or not, molten salt technology was viable; the Oak Ridge National Laboratory in Tennessee had successfully operated a demonstration reactor back in the 1960s. And more to the point…, the liquid nature of the fuel meant that they could potentially build molten salt reactors that were cheap enough for poor countries to buy; compact enough to deliver on a flatbed truck; green enough to burn our existing stockpiles of nuclear waste instead of generating more — and safe enough to put in cities and factories. That’s because Fukushima-style meltdowns would be physically impossible in a mix that’s molten already. Better still, these reactors would be proliferation resistant, because their hot, liquid contents would be very hard for rogue states or terrorists to hijack for making nuclear weapons.

Molten salt reactors might just turn nuclear power into the greenest energy source on the planet.

It sounds paradoxical — they’re safe from meltdowns because they’re already molten? But the thing is, they’re designed to contain material at that temperature to begin with, and since it’s already liquid, any temperature runaway would just make it expand until the reaction shut down. Plus the coolant wouldn’t need to be under pressure so there’d be no risk of a steam explosion, and there’s a failsafe built in that would drain the molten salts into an underground tank so they wouldn’t be released into the environment. The one real problem, it seems, was finding a sufficiently corrosion-resistant material to make the tanks and pipes from.

Better yet, the liquid nature of the nuclear fuel means that it could be continuously filtered, purified, and cycled back into use like the liver cleansing the bloodstream, so eventually all the nuclear material would be used up and there’d be no nuclear waste — or rather, what little waste there was would have a short enough half-life to be safe after about 300 years rather than a quarter of a million. What’s more, it could use some of our existing nuclear waste as fuel and help reduce that problem too.

So why was this superior technology abandoned decades ago in favor of the riskier water-cooled, solid-fuel nuclear plants? Largely just industrial and political inertia, it seems. The solid-fuel design was already in use on nuclear subs when the effort to build civilian nuclear power plants got underway, and the molten salt design was still experimental. So by the time molten salt technology was experimentally proven viable, the industry was already fully committed to solid-fuel reactors, with a big infrastructure built up to support them and deal with their fuel. And there were big plans to recycle their fuel in breeder reactors and create more and more plutonium to power future reactors, which seemed like a great idea until it turned out you could build bombs from the spent fuel, which meant the recycling plan was shut down and we were stuck with a bunch of nuclear waste we didn’t know what to do with, and that problem plus Three Mile Island and Chernobyl soured people on any nuclear-fission research, even something like molten salt reactors that would be far safer and cleaner and have none of the drawbacks that made people so afraid of fission power. But now, people (at least those who aren’t in denial) are more afraid of climate change and are looking for green energy sources, and this might be one of the best.

Then again, MSRs are not a perfect technology. I looked around and found another site talking about the tech:

Molten Salt Reactors

This article is more cynical about the downsides of the tech than the Discover article, asserting that it could be used to create weapons after all, and that there are a number of unknowns yet to be addressed.

And here’s the World Nuclear Association’s assessment, which mentions that MSR research is already pretty big in China, something the Discover article doesn’t mention:

Molten Salt Reactors – World Nuclear Association

Although it doesn’t seem to agree with the previous article about the weapons risk, barely mentioning the issue in its discussion, and suggesting that the early research into the technology was specifically focused on finding a form of nuclear power that would minimize the proliferation risk. So evidently there are differing points of view on this, which is why it’s always a good idea to look beyond a single source.

This is informative stuff for a science fiction writer like me. For decades, SF writers have assumed that the future of clean nuclear power would be fusion rather than fission. I’ve long been a believer in the aneutronic form of fusion that would react deuterium with helium-3 (which is abundant on the Moon due to being deposited by the solar wind) and react without neutron radiation. But it turns out there’s been a viable, safe, fairly compact fission technology that’s been known about this whole time and largely ignored — already pretty much proven viable, while fusion has remained just out of reach (they’ve been predicting it was 30-40 years away for the past 50-60 years now). I mean, sure, a reactor based on what’s essentially a pit of radioactive lava sounds scary, but no more so than a starship engine based on constantly annihilating matter and antimatter.

It’s also a good reminder that technology doesn’t always develop in a straight line — that viable advances can be sidelined for a generation or more because industries choose to concentrate all their attention elsewhere, or because the political will to explore them is lacking. Of course, there’s no shortage of SF stories about scientists (often of the mad persuasion) trying to prove to Those Fools at the Institute that a discredited fringe idea is viable after all, but it might also be worth exploring what comes after that, when the fringe idea finally starts to get acceptance — or when it was never really discredited to begin with, just overshadowed and forgotten until the hero of the story tried digging into old research and turned up an overlooked gem.

By the way, it’s amusing to read that the molten uranium-salt mixture has “a lovely green tint,” given that the public has long associated radioactivity with a green glow. That myth arose as a result of the glow-in-the-dark radium clock and watch faces that were common back in the days before it was understood how dangerous radioactivity was. The green glow wasn’t from the radium itself, whose emissions (like those of all radioactive isotopes) are invisible; rather, the radioactivity excited luminescence in the phosphor dyes the radium was mixed with. But since such items were common in the early 20th century, people assumed that anything radioactive would glow green, which is part of why the Incredible Hulk is that color (although it’s largely because his original gray hue was hard to reproduce consistently with cheap 1960s printing methods), along with various vintage monsters like those in The Green Slime and Doctor Who‘s “The Green Death,” and why the nuclear rod prominently featured in the titles of The Simpsons glows green. It’s also probably why kryptonite is green. So anyway, given that I’ve grown used to thinking of “green radiation” as a total myth, it’s ironic that the molten salt fuel in this case actually is green in color (though presumably not glowing except thermally) — not to mention that it’s a “green” power source in the environmental sense!

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“Crooked Hub” discussion and annotations are up!

You know the drill — the new Analog is on sale now, so I’ve updated my Hub Series page with non-spoiler discussion of “…And He Built a Crooked Hub,” plus a link to the spoiler annotations page, which I trust folks will save until after they’ve read the story. You’ll need to scroll down a bit, since I decided to put it below the “Hubpoint of No Return” discussion, which just seemed logical.

I tried looking for online reviews to quote, but apparently it’s a bit early for those.

For some reason, while it took me ages to get around to finishing the previous issue I was in, I’m already nearly finished with the current issue; I’ve read everything but the novella. Some interesting stuff in this one, including a sci-fi twist on the French Revolution called “The Pendant Lens” by Sean McMullen, a story of AI activism called “Optimizing the Verified Good” by Effie Seiberg, a twisty monster-movie deconstruction called “The Unnecessary Parts of the Story” by Adam-Troy Castro, and a handy science-fact overview of “Alien Biochemistry” and its possible forms by Jay Werkheiser, useful for the SF worldbuilder.

Memory RNA after all?

Today I’m experiencing that common occupational hazard for the science fiction writer: Learning that a new scientific discovery has rendered something I wrote obsolete.

I’ll let Tamara Craig, the narrator of my 2010 story “No Dominion” from DayBreak Magazine, explain:

Nearly a century ago, an experiment with flatworms seemed to show that memory was stored in RNA and could be transferred from one organism to another. But the experiment had been an unrepeatable fluke — pardon the pun — and later research showed that memory worked in a completely different way, unfortunately for the science fiction writers who’d embraced memory RNA as a plot device.

(This passage is trimmed down a bit in the version soon to be reprinted in Among the Wild Cybers: Tales Beyond the Superhuman, since that collection’s editor thought the references to SF writers were a bit too meta and distracting.)

What I wrote there was based on memory and was roughly correct. In the late 1950s and early ’60s (“No Dominion” is set in 2059), a researcher named James V. McConnell spent years experimenting with memory in planaria (flatworms), doing things like cutting them up and testing if their regenerated tails retained the memories of their original heads, and — most famously — grinding them up and feeding them to other flatworms. McConnell’s research did seem to show that some learned behavior was passed on by what he proposed to be a form of RNA storing memories created in the flatworm’s brain. It’s true that there was never enough reliable confirmation of his result to establish it as true, and the scientific establishment dismissed McConnell’s findings, although they did inspire a lot of science fiction about RNA memory drips or memory pills as a technique for quick-learning overnight what would normally take months or years. However, it seems that there were some experiments that did appear to replicate the results. There just wasn’t enough consistency to make it definitive.

Apparently, there’s been some renewed experimentation with McConnell’s theory in the past few years, showing promising but uncertain results. What I read about today was a new result, involving snails rather than flatworms:

http://www.sfn.org/Press-Room/News-Release-Archives/2018/Memory-Transferred-Between-Snails

Memories can be transferred between organisms by extracting ribonucleic acid (RNA) from a trained animal and injecting it into an untrained animal, as demonstrated in a study of sea snails published in eNeuro. The research provides new clues in the search for the physical basis of memory.

Long-term memory is thought to be housed within modified connections between brain cells. Recent evidence, however, suggests an alternative explanation: Memory storage may involve changes in gene expression induced by non-coding RNAs.

A more thorough article about the result can be found at the BBC:

‘Memory transplant’ achieved in snails

Now, this doesn’t mean the original memory RNA idea was altogether right. This experiment involved injecting the RNA into the blood of the snails rather than feeding them ground-up snails. And the result probably needs to be repeated more times and studied more fully before it can be definitive. But it does suggest that I was wrong to insist that memory “worked in a completely different way.” It’s possible that memories are stored, not in patterns in the synapses of nerve cells, but in RNA in their nuclei, which has an epigenetic effect on the neurons’ gene expression and therefore their behavior and structure.

Of course, all these results show is that very simple reactions to stimuli can be transferred. There’s no evidence that it would work for something as elaborate as the kind of declarative memory and knowledge that the passage in the story was discussing, or the kind of procedural memory and skills often transferred by memory RNA in fiction (e.g. foreign languages or fighting techniques). Perhaps those kinds of memory are partly synaptic, partly epigenetic. Maybe there’s something else involved. So Tamara’s lines in the story may not be entirely obsolete, just a little inaccurate (forgivable, since she’s a cop, not a scientist).

So I guess it could be worse. It was a minor part of the story anyway. And the actual research itself suggests some interesting possibilities. The articles say that learning more about memory creation and storage — and perhaps memory modification and transfer — could help treat conditions like Alzheimer’s and PTSD. If so, then it’s unfortunate that McConnell’s results weren’t taken more seriously half a century ago.

Quantum teleportation revisit: Now with wormholes!

December 12, 2017 1 comment

Six years ago, I wrote a couple of posts on this blog musing about the physics behind quantum teleportation — first proposing a model in which quantum entanglement could resolve the philosophical condundrum of whether continuity of self could be maintained, then getting into some of the practical limitations that made quantum teleportation of macroscopic objects or people unlikely to be feasible. I recently came upon an article that offers a potential new angle, basically combining the idea of quantum teleportation with the idea of a wormhole.

The article, “Newfound Wormhole Allows Information to Escape Black Holes” by Natalie Wolchover, was published in Quanta Magazine on October 23, 2017. It’s talking about a theoretical model devised by Ping Gao, Daniel Jafferis, and Aron C. Wall, a way that a stable wormhole could exist without needing some kind of exotic matter with arbitrary and probably physically unattainable properties in order to keep it open. Normally, a wormhole’s interior “walls” would attract each other gravitationally, causing it to instantly pinch off into two black holes, unless you could line them with some kind of magic substance that generated negative energy or antigravity, like shoring up a tunnel in the dirt. That’s fine for theory and science fiction, but in practical terms it’s probably impossible.

The new model is based on a theory that’s been around in physics for a few years now, known in short as “ER = EPR” — namely, that wormholes, aka Einstein-Rosen bridges, are effectively equivalent to quantum entanglement between widely separated particles, or Einstein-Podolsky-Rosen pairs. (Podolsky, by the way, is Boris Podolsky, who lived and taught here in Cincinnati from 1935 until his death, and was the graduate advisor to my Uncle Harry. I was really impressed when I learned my uncle was only two degrees of separation from Einstein.) The EPR paradox, which Einstein nicknamed “spooky action at a distance,” is the way that two entangled particles can affect each other’s states instantaneously over any distance — although in a way that can’t be measured until a light signal is exchanged between them, so it can’t be used to send information faster than light. Anyway, it’s been theorized that there might be some sort of microscopic wormhole or the equivalent between the entangled particles, explaining their connection. Conversely, the two mouths of a wormhole of any size could be treated as entangled particles in a sense. What the authors of this new paper found was that if the mouths of a wormhole were created in a way that caused them to be quantum-entangled — for instance, if one of them were a black hole that was created out of Hawking radiation emitted from another black hole (it’s complicated), so that one was a direct outgrowth of the other on a quantum level — then the entanglement of the two black holes/mouths would create, in the words of the paper’s abstract, “a quantum matter stress tensor with negative average null energy, whose gravitational backreaction renders the Einstein-Rosen bridge traversable.” In other words, you don’t need exotic matter to shore up the wormhole interior, you just need a quantum feedback loop between the two ends.

Now, the reason for all this theoretical work isn’t actually about inventing teleportation or interstellar travel. It’s more driven by a strictly theoretical concern, the effort to explain the black hole information paradox. Conservation of energy says that the total amount of energy in a closed system can’t be increased or decreased. Information is energy, and the universe is a closed system, so the total amount of information in the universe should be constant. But if information that falls into a black hole is lost forever, then conservation is violated. So for decades, physicists (notably Stephen Hawking) have been exploring the question of whether it’s possible to get information back out of a black hole, and if so, how. This paper was an attempt to resolve that question. A traversable wormhole spinning off from a black hole provides a way for information to leave the interior of the black hole, resolving the paradox.

I only skimmed the actual paper, whose physics and math are way beyond me, but it says that this kind of entangled wormhole would only be open for a very brief time before collapsing. Still, in theory, it could be traversable at least once, which is better than previous models where the collapse was instantaneous. And if that much progress has been made, maybe there’s a way to refine the theory to keep the wormhole open longer.

There’s a catch, though. Physical law still precludes information from traveling faster than light. As with quantum teleportation, there is an instantaneous exchange of information between the two ends, but that information remains in a latent, unmeasurable state until a lightspeed signal can travel from the transmitting end to the receiving end. So a wormhole like this, if one could be created and extended over interstellar distances, would not allow instantaneous travel. A ship flying into one end of the wormhole would essentially cease to exist until the lightspeed signal could reach the other end, whereupon it would emerge at long last.

However — and this is the part that I thought of myself as an interesting possibility for fiction — this does mean that the ship would be effectively traveling at the speed of light. That in itself is a really big deal. In a physically realistic SF universe, it would take an infinite amount of energy and time to accelerate to the speed of light, and once you got fairly close to the speed of light, the hazards from oncoming space dust and blueshifted radiation would get more and more deadly. So as a rule, starships would have to stay at sublight speeds. In my original fiction I’ve posited starships hitting 80 or 90 percent of c, but even that is overly optimistic. So in a universe where starships would otherwise be limited to, say, 30 to 50 percent of lightspeed, imagine how remarkable it would be to have a wormhole transit system that would let a starship travel at exactly the speed of light. Moreover, the trip would be instantaneous from the traveler’s perspective, since they’d basically be suspended in nonexistence until the lightspeed signal arrived to “unlock” the wormhole exit. It’s not FTL, but it’s L, and that alone would be a damned useful stardrive. You could get from Earth to Alpha Centauri in just 4.3 years, and the trip would take no time at all from your perspective, except for travel time between planet and wormhole mouth. You’d be nearly 9 years younger than your peers when you got home — assuming the wormhole could be kept open or a second temporary wormhole could be generated the other way — but that’s better than being 2 or 3 decades younger. Short of FTL, it’s the most convenient, no-fuss means of interstellar travel I can think of.

Or, looked at another way, it’s a method for interstellar quantum teleportation that avoids all the scanning/transmission obstacles and impracticalities I talked about in my second 2011 post on the subject. No need to use a technological device to scan a body with a level of detail that would destroy it, then transmit a prohibitively huge amount of data that might take millennia to send in full. You just pop someone into one end of a wormhole and make sure the handshake signal is transmitted strongly enough to reach the other end. I’ve long felt that wormhole-based teleportation would be a more sensible approach than the disintegration-based kind anyway. Although we’re technically talking about black holes, so it wouldn’t be the sort of thing where you could just stand on a platform in your shirtsleeves and end up somewhere else. Also, there might be a little problem with getting torn apart by tidal stresses at either end. I’m not sure the paper addresses that.

This idea could be very useful for a hard-SF universe. My problem is that the universes I have established are a little less hard than that, though, since I tend to like working in universes with FTL travel of one sort or another. But maybe some idea will come to me for a future story. And maybe some other writer will read this and get an idea. We’re all in this together, and any worthwhile SF concept can inspire multiple very different stories.

Michigan trip followup

November 5, 2017 3 comments

Well, I’ve been back from my visit to the Detroit area for a couple of days. I had a pretty uneventful drive both ways, taking about 6 hours each way, what with stops for rest breaks, lunch, and fuel. (I had half a tank when I started, and I realize in retrospect that if I’d waited to fill up until it was low, I could probably have made the round trip with just one refill. But I didn’t.) The only problem is that my GPS shut down on me a couple of times, including while I was in the middle of Detroit rush hour traffic. That’s the second trip I’ve had where that happened — I wonder what the problem is. My smartphone is a few years old now, so maybe planned obsolescence is starting to kick in. Anyway, I don’t really need GPS for most of the trip, since it’s just straight up and down I-75. It was just the last leg getting to Huntington Woods, and getting from there back to 75 South, that I still need a reminder for.

So I had a nice little visit with family, and the book signing at the Huntington Woods Public Library was on Wednesday evening. It was a much smaller group than I’d hoped for. Apparently the World Series was in its seventh game that night or something, although I wouldn’t think there’d be that much overlap between my audience and sports fans. But whatever the reason, there were only about a half-dozen or so people there. So we all sat around one round table and had a nice little chat about writing and Star Trek and stuff for 90 minutes. I gave away most of my giveaway copies of Patterns of Interference, but I only sold one book. I was hoping for more financially, but otherwise I can’t complain. I guess I shouldn’t have expected a huge group (although the library reserved a really big meeting hall for me).

The one other thing of note I did on my trip was to visit the Cranbrook Institute of Science, a natural history museum that’s part of the larger Cranbrook Educational Complex, itself a historic landmark. Alas, I couldn’t afford the extra fee for the chocolate exhibit they’re currently showing, but the rest of the museum was interesting, particularly the geological specimens. I quite liked this iridescent fossil shell in the lobby, which came out really nicely in my photo, with a fiery glow seemingly from within:

Cranbrook fossil shell

And here’s an item from the geology exhibit that’s close to my heart:

Beryl, var. Emerald(I think I once briefly considered using Beryl as Emerald Blair’s middle name. I figured it was too on the nose.)

They had a section on meteorites too, including a really nice Don Davis painting of the Tunguska event, which can also be seen here. There was also a replica T. rex skeleton that you can get really close to — I’m not sure I’ve ever really gotten a sense of just how big they were. That would’ve been scary. There was also a Michigan-centric section about Ice Ages and glaciers carving the landscape, and an anthropology section with items from various world cultures all displayed together. That section had a video presentation using that so-called “hologram” technology that projects what looks like a freestanding, translucent flat image in open space. I ducked down to the side to take a closer look at how it works, and it’s quite simple — there’s a horizontal video screen in the ceiling and a glass plate at a 45-degree angle reflecting it (basically a beam splitter), so that the reflection looks like it’s floating upright in the air behind the glass. They set it up so that the “holographic” characters (of course this has nothing to do with actual holography) appeared to be occupying the 3D physical display behind the glass, with the hostess standing on the carpet and a little towheaded kid right out of ’60s sitcom central casting sitting on a chest and listening to her lecture about human diversity. Since they were both in the same plane, the perspective of the illusion held up well as I moved from side to side, as long as I didn’t move far enough to see how flat their images really were. The bench in front of the display was not so wide as to spoil the illusion for kids sitting on the ends. But this is me we’re talking about — when I see an illusion, I want to see how it’s made. I was always more interested in knowing the magician’s point of view than the spectator’s.

As I mentioned, the drive home on Friday was pretty uneventful, but one weird thing happened: I got 4-5 spam calls on my smartphone within just a few hours, an astonishing number. Most of them I just rejected because I was driving at the time, but there was one that went to voicemail that was an incredibly inept scam, an obviously synthesized voice speaking in hilariously ungrammatical English about how I had to pay my overdue IRS bill or something or I would get arrested “by the cops.” I wonder why there were so many calls on that day alone.

So now I’m back home, caught up on my missed TV shows, and trying to get back to work. I’m doing copyedits for a project I should be able to announce soon, and expecting copyedits for another project I hope I can announce before much longer. Plus I just got a phone call reminding me that Election Day is on Tuesday, so I should remember to research the candidates and issues before then. (I’ve been getting a ton of election fliers in the mail, but I prefer to get my info from independent sources.)

And of course, I’ll be at Erlanger’s LibraryCon this Saturday, November 11, from 11-4. This should be a bigger event, so hopefully there will be more folks around to buy my books.

Ars Technica interviewed me on STAR TREK transporters

September 23, 2017 5 comments

You may recall that last year, Xaq Rzetelny of the science site Ars Technica interviewed me about Star Trek temporal physics. Well, Xaq recently came across my 2011 post “On quantum teleportation and continuity of self,” and sought my input for an article tackling the same basic question for Star Trek transporters — whether or not the person who comes out of the transporter is the same one who went in. It’s a detailed and well-researched piece that also contains comments from folks like Michael Okuda and Lawrence Krauss, and you can read it here:

Is beaming down in Star Trek a death sentence?

Musings on “Abductive Reasoning” and universes (mild spoilers)

I had an interesting thought last night about my newly published story in Analog, “Abductive Reasoning.” I’ve been assuming all along that AR was in its own self-contained universe, unconnected to any of my other “written worlds.” As I mentioned once before, there’s no specific reason it couldn’t theoretically share a universe with my other standalone story, “No Dominion,” but there’s no reason they should be connected either, since they’re rather different in tone and focus. It can’t be set in the Only Superhuman universe (as ISFDb calls my default continuity), since that universe includes a faster-than-light drive technology, the warp cage, while the protagonist of AR travels with her consciousness encoded on a biochip in a palm-sized “wafer ship” that travels at high sublight speed using vacuum-energy sails and takes millennia to cross significant galactic distances. If the technology for warp propulsion were possible in AR’s universe, surely its Galactic Coalition would’ve discovered it long ago. Plus, the existence of that Coalition is incompatible with the galactic history and politics I’ve developed in my main universe.

I assumed the same arguments would apply to the universe of my Hub stories, the other comedy tales I’ve done for Analog. As works of science fiction humor, they could potentially go together, but the Hub universe also includes a form of faster-than-light travel, the Hub itself, plus the Hub Network that’s grown up around it and encompasses nine different galaxies, including much of the Milky Way. It seemed obvious that the Hub Network and the Galactic Coalition couldn’t exist in the same reality without being aware of each other, and if the GC knew about the Hub, then surely they’d use it instead of taking centuries to traverse the stars in wafer ships, right?

But last night I started to wonder if that was really the case. The GC’s citizens, or at least those like “Abductive Reasoning”‘s protagonist Cjek’darrit, are effectively immortal in biochip form, and presumably can place their minds in a dormant state for most of a lengthy interstellar journey. Culturally, they might be satisfied with the slowness of sublight travel despite being aware of an instantaneous alternative. Maybe they don’t even get along with the Hub Network; maybe there’s some political, ideological, or economic reason that they refuse to associate with the Network or vice-versa. Still, those seem like feeble justifications.

Then it occurred to me that the key to viable two-way Hub travel is the use of quantelopes — the bioengineered animals that communicate through quantum entanglement, the only way a ship can send a signal to the Hub to call for the opening of the nearest known Hubpoint. So ships using the Hub Network need to be large enough to carry at least one or two rabbit-sized animals and their cryogenic life-support tank. A wafer ship therefore couldn’t use the Hub! Except, hang on, the Coalition’s member species are (at least in Cjek’s case) born as organic beings and live that way in nanofabricated bodies when they’re on planets. So they don’t need to use wafer ships exclusively. They could use regular spaceships and Hub travel if they were aware of the Hub’s existence. So that doesn’t explain it.

But that leads to the next possibility: What if the Galactic Coalition and the Hub Network simply aren’t aware of each other yet? The Hub isn’t like warp cages. It isn’t a technology that could be theorized and invented; it’s unique, a physical property of the galaxy’s center of mass. If you hadn’t had the good fortune of some Network scout discovering a Hubpoint near your star system, you’d have no way of knowing it existed. So in theory, a large interstellar civilization adapted to use slower-than-light travel could share the galaxy with the Hub Network without the two having encountered each other yet. It’s a big galaxy with hundreds of billions of star systems, after all. Statistically, it’s at least possible. Although AR implies that the Coalition is extremely ancient and pervasive, so it might be hard for them to miss each other.

Then it struck me — the Hub Network is not ancient, certainly not on the same scale. “Home is Where the Hub Is” establishes that the Hub was discovered by the Dosperhag only 16,000 years ago, making the Network at least several centuries younger than that. But AR says that Cjek’s “creche-mates only reconverged at the home star once every few hundred galactic microrotations.” A galactic rotation, at least at Earth’s distance from the center, takes about 250 million years, so a hundred microrotations is 25,000 years. So journeys through the Coalition take tens of millennia at high sublight speeds, meaning that new information transmitted at the speed of light would take a similar amount of time to propagate. If the Hub Network is about 16,000 years old, then the odds are that contact with the GC would’ve most likely happened somewhere near the middle of that span, say around 8 millennia ago give or take — except the Hub has grown in size and activity over time, which would make contact statistically more likely to have occurred in the latter half of that span. So it’s reasonably likely that if the two civilizations have made contact, it was only within the past few millennia. And since it takes tens of millennia for new information to cross the entire Coalition, that news might not yet have spread far enough to reach any world Cjek’darrit has visited lately. So it could work.

Although… wait, hold the phone. There’s the other side of the question to consider. The Network may only be 15-16,000 years old, but the Hub, as I said, is an intrinsic property of the galaxy, so it’s been there for 13-odd billion years. If the Coalition existed in the Hub universe, and has been traveling the galaxy for hundreds of thousands of years at least, then it’s quite possible they — or one of the multiple starfaring civilizations that came together to form them — would’ve discovered the Hub long before the Dosperhag did. I’ve established that the Hub is a radiation source, constantly emitting EM radiation and signals that leak through from every point in the greater galaxy. It’s not an especially intense emitter, since ships can safely pass through it on a routine basis, but it would emit a rather unique radiation signature that could be detected from a distance if it weren’t yet encased in the Shell that the Dosperhag had built around it. So Coalition wafer ships or microsail probes passing near that region of space could well have discovered it on their own long ago.

So… okay. It’s theoretically possible that “Abductive Reasoning” takes place in the Hub universe. It isn’t conclusively ruled out by the stories to date. And there’s certainly some appeal to the idea of putting all my SF comedy stories in a shared reality. So last night, I thought it was a reasonable idea, but after sleeping on it, I have to say it seems unlikely — and probably undesirable. Having the Galactic Coalition unaware of the Hub Network would not be out of the question, but it would require imposing significant constraints on the GC’s age, spread, and knowledge of the galaxy, constraints that don’t quite fit with what I implied in the story and that would limit my options if I wanted to write more stories in that setting. Having the GC know about the Hub, either through contact with the Network or through prior discovery, and nonetheless choose not to take advantage of its convenience would require making some rather arbitrary and limiting assumptions about their culture or politics. It could potentially happen; for all I know, I could come up with a story idea about the two civilizations interacting, and then I’d have reason to tweak things to fit. It’s nice to know I at least have that option. But it doesn’t really feel right to treat them as the same universe without good reason. I didn’t conceive them that way, so they don’t naturally mesh without a fair amount of contrivance. I could change my mind in the future, but for now, better to let them stand as their own entities. (This is why I prefer to develop unified continuities from the start, rather than grafting separate stories together after the fact.)

And that’s fine. It would’ve been fun to discover an unexpected opportunity to merge the universes, but on the other hand, I liked writing a story set in a universe without FTL, without the usual kind of spaceship. I like it that this little comedy story is perhaps my most scientifically plausible, cutting-edge depiction of interstellar travel yet. And if I do more with the setting, I’d probably prefer to embrace the things that make it different from my other universes.

Still, it would be perfectly fine with me if everyone reading this post went out and bought copies of the Sep/Oct 2017 Analog and the eBook collection Hub Space: Tales from the Greater Galaxy (just follow the above links, then follow the ordering links of your choice therein), if you don’t have them already, so you can compare the universes and decide for yourselves. Because people buying my stuff is good.