view from a hotel window

I’m in Manchester for a meeting today.  So, another day, another hotel.

sunrise over Manchester: 8:15 GMT

UCNC day 5

The final (half) day of UCNC in Manchester.

The last invited speaker of the conference was Steve Furber, talking about the SpiNNaker project (SpiNNaker stands for  "Spiking Neural Network Architecture").  After some interesting historical context, he told us of the SpiNNaker machine: one million processors in an asynchronous spiking architecture.  The preliminary machine, with 500,000 cores, was launched 30 Mar 2016, and more cores have been added since.  It can be programmed in the Python PyNN language.  For example, 165 lines of Python are needed for a Sudoku solver, where the neuronal groups inhibit other groups with the same integer value in the the same row, column, or 3x3 cell.  Once a solution has been found, the inhibitory links decrease, and the spiking rate goes up, solving a "diabolical" puzzle in about 10 seconds.  This isn't just a toy: it is representative of complex constraint problems.  So far people have only been running small programs, as they think how to scale up their ideas.  Although each core is a standard processor, exploiting the asynchronous spiking communication requires a different way of thinking.

Then on to the final technical session.  First was a talk on "Model-Based Computation"; an attempt to extend the definition of analogue computation (which implements a model analgous to the problem) in a way that can cover more of unconventional computation.  Then a couple of mathematical talks about chemical reaction system formalisms.  The first, "Towards Quantitative Verification of Reaction Systems" encoded the system in a formal solver to prove properties.  The next, "Reachability Problems for Continuous Chemical Reaction Networks" looked at proving safety properties in systems with continuous values of reactant concentrations.  The final talk was on "Global Network Cooperation Catalysed by a Small Prosocial Migrant Clique", looking at evolutionary game theory in networks with no global knowledge, and how a small clique of cooperators migrating into a network of defectors could change it to a network of cooperators.

So, another conference ends.  Next year, in Arkansas.

After two solid weeks of travel and listening, my brain is full of exciting science, and I need a lot of sleep!  I'm looking forward to getting home for a bit of a rest.

UCNC day 4

UCNC day 4, with an embarrassment of riches in the form of invited talks.

We kicked off with an invited talk from Friedrich Simmel on “Chemical Communication Between Cell-Sized Reaction Compartments”. This was a fascinating account about a series of experiments sending signals between cells, droplets, and “genelets” (droplets containing cellular “naked” genetic machinery), based on the ideas of quorum sensing: when a high enough chemical signal concentrations is produced, because there are enough producers around, it invokes a response. We saw droplets signalling the chemicals, inducing bacteria to react, and that signal propagating through multiple droplets. Apparently there is a “bacterial Turing test”: can you make a droplet that a bacterium will interact with (through chemical signals) just as if it were another bacterium? These systems pass it. Through a clever use of microfluidics, we saw videos of sheets of bacteria interacting, via fluorescent protein production. The fluorescence increases both due to the being switched on by the signalling, and due to the bacteria reproducing, two process with similar timescales. The possibilities of this approach include forming spatial and temporal patterns through reaction-diffusion systems of interacting genetically programmed droplets. If all this wasn’t enough, Simmel finished his talk with a description of using electron lithography to etch chips, deposit gene-length strands of DNA in a controlled manner, which could then be manipulated to stick together (condense) into linear bundles. It’s early days yet; next on the agenda is using gene expression to control the condensation. Heady stuff!

Next was the workshop on Physics and Computation. Gilles Dowek started with an invited talk on “Quantitative Informational Aspects in Discrete Physics”. Gandy has shown that if a system (1) is homogeneous in space and time; (2) has a bounded speed of information transport; (3) has a bounded density of information, then it can be simulated by a cellular automaton. Since physics appears to satisfy these properties, it should be so simulable. Then came a short but necessary digression on Planck’s constant. The physical constant c has the dimensions of a speed, and it is the speed of light. Planck’s constant has the dimension of an action; what action is it? After a bit of discussion, it turns out that it is (a small multiple of) the area of a bit of information (in a particular choice of units where everything has a dimension that is some power of length) as given by the Bekenstein bound. Then Dowek went through how to build a CA in Newtonian physics, special relativity, and general relativity, that models free fall (subject to some assumptions). It can’t be done in Newtonian physics, because there is no bound on speed. In SR it can be done, with particles that contain 320 bits of information (using the Planck area); in GR they only need 168 bits. This is an existence proof, but the CAs defined are not very satisfactory, for several reasons. The task is to do better! Listening to this, I recalled Randal Beer’s Game of Life talk from ALife last week: looking at a CA in terms of processes rather than cells gives a much more natural formulation. I wonder if that would work here? 

Then we had a talk about “The Information Content of Systems in General Physics Theories”. The idea here is to look at a broad range of probabilistic theories, of which quantum mechanics is one instance. Investigating their computational complexity of the “advice” given by a physical system can shed light on what makes QM special, different from just a general theory.

After lunch Ana Belén Sainz gave an invited talk on “Postquantum Steering”. This was in the same vein as the previous talk: look at a general theory, then compare with QM. Here the idea was applied to one particular kind of system: how much can Bob “steer” distant Alice’s state, by making measurements on his own state?

Next came some more talks. The first, on “Sequent Calculus Representations for Quantum Circuits”, was an approach to making reasoning about quantum circuits look like proof theoretic reasoning in other branches of computer science, by finding an appropriate set of axioms. Next was a talk on “Physical Computation, P/poly and P/log*”, looking at the computational complexity of physical computing as an unconventional co-processor, in terms of its advice complexity. After coffee we had a talk on “Local Searches Using Quantum Annealers: How to Beat Noise and Take Advantage of the Classical Algorithms we Already Have, or, Modernising Quantum Annealing using Local Search”. This contrasted classical simulated annealing, including its two improvements of parallel tempering and population annealing, with the quantum version: quantum annealing. Each has is strengths and weakeness; here was a suggestion of how to use the quantum annealing as a “subroutine”, getting the best of both approaches. The final workshop talk was on “Quantum Probability as an Application of Data Compression Principles”, a philosophical look at probabilities in general, and branching world probabilities in particular.

The day was then completed with a further invited talk, Bob Coecke talking “In Pictures: From Quantum Foundations to Natural Language Processing”. He zipped through a beautiful, formal, diagrammatic notation for quantum systems, and how the power of this notation makes many complicated quantum puzzles ad proofs essentially vanish. There will be a book, Picturing Quantum Processes, from Cambridge University press covering this published soon.  It's 922pp: pictures take a lot of space!  After all this the quantum mechanics, he went off in an unexpected direction, by showing how the very same notation could be used to calculate the meaning of sentences from their underlying grammar and the meaning of the individual words. Some modern meaning systems use high dimensional vectors to encapsulate word meanings. Adding the grammar via the diagrams improves the calculated meaning enormously. Thinking about the mathematical structures needed leads to the suggestion of using density matrices rather than vectors, to cope with ambiguous meanings. I love this kind of work: a deep piece of work in one domain that is not only applicable in a seemingly unrelated domain, but that suggests advances there, too.

UCNC day 3

UCNC day 3. Well, only half a day, as the afternoon was reserved for exploring Manchester.

We started with a super invited tutorial on “Self-Assembling Adaptive Structures with DNA”, by Rebecca Schulman. Rather than trying to assemble arbitrary structures, let’s just look at what can be done with 1D systems: filaments of DNA nanotubes than can controllably be built into strings, trees, and network structures. She pointed out that it doesn’t make sense to build every structure from weaving pure DNA: a human-size object would need about 3 light years of it. But smaller things can sensibly be built this way. This approach doesn’t include only static structures: movement can be achieved by growing at the front and dissolving at the back. This is the way the cytoskeleton in cells works to move them around. DNA nanotube growth can be controlled by a variety of chemical processes, but it’s hard to design different systems: there’s no good enough model or simulation of how it all works.  Currently things are a mixture of approximate yet expensive simulations, and lab experiments. But this is clearly a very powerful and rich area.

This was followed by the technical session: three talks related to DNA computing. The first was implementing a circuit model in a 2D gellular automaton. Next was another gellular automaton system: a maze solver. We finished the morning with a description of implementing a stack (the push-pop data structure) in DNA: the design is fascinating, and it has been implemented, at least for stack sizes of three. Again, this work is just a hint of things to come.

Then off to explore the wilds of Manchester…

UCNC day 2

UCNC day 2, a full day of talks.

First up was Masami Hagiya with an invited tutorial on “Gellular Automata”. These are a form of cellular automata implemented using gels and chemical reactions. The walls between cells can be “decomposed” or “composed” using chemical reactions – or instead can “swell” or “unswell” forming a valve. This allows chemicals to move between cells. There are theoretical results demonstrating these systems can in principle implement certain kinds of CAs. The tutorial moved on to talking about implementations. Most of the manipulations involve a form of DNA chemical computing: using complementary strands to form networks of polymers, or to control diffusion by attaching anchors. These processes can be controlled by the DNA technique of “strand displacement” that breaks the bonds between the complementary strands. There are some initial prototype implementations. These are still rather complicated, needing multiple chemical species to implement relatively simple state transitions. However, it is early days yet, and more efficient approaches may well be discovered.

Next was the workshop on Membrane systems (mostly P-Systems). Rudolf Freund started off with a tutorial, helping to introduce the concepts to people not that familiar with the area. Then on to the technical talks, covering a wide set of membrane computing topics.

Finally was the afternoon technical session. We started with a talk on Affine Automata: these use an underlying logic that is partway between classical probabilistic automata and quantum automata. Next was a talk about languages (sets of strings) arising from finite walks on Sierpinsky gaskets. And finally we had a talk on Matrix Ins-del (insertion deletion) systems (although I think a better name would be List Ins-del systems). These three combined nicely as a range of different ways of looking at language (in the CS sense) recognisers.

Then off to The Great Wall Chinese restaurant, for a very nice duck in ginger.

UCNC day 1

Another week, another conference.

I have moved from Cancun, Mexico, at the ALife conference, to Manchester, UK, for the conference on Unconventional Computation and Natural Computation (UCNC). It is very weird for me to be at a conference in the UK with “wrong way” jet lag!

The first day was a half day, starting with lunch – very civilised. The first talk was a tutorial from Jon Timmis on Swarm Robotics. This subject has multiple simple automomous robots working together with no global control, to produce an emergent behaviour and capability that none has individually. The tutorial covered the history of the subject, showing how some of the original constraints have become irrelevant: today’s “simple” robots are actually quite sophisticated compared to those at the discipline’s inception; and the original “nature inspiration” is no longer so prominent: use it if it helps, ignore it if it doesn’t. There are a couple of issues that make the subject difficult. The first is, how to design the local, individual robot rules that produce the desired emergent behaviour (and doesn’t produce undesired behaviours also)? This often reduces to an iterative design: suggest, test, refine, which can be automated in a search algorithm, such as an evolutionary search. This leads to the second issue: this search is most efficiently done in simulation, but there is a “reality gap” in simulation: the simulated physics is often too simplistic, leading to “overfitting” to the simulation and the solution then not working on the embodied physical robots. There are lots of fascinating results addressing these issues: the next challenge is moving this research out of the lab into the real world.

Then on to the technical session, with four talks. First up was my student, talking about using reservoir computing as an unconventional virtual machine for computing with carbon nanotubes: evolving the carbon nanotube system into a “good” reservoir, then training that reservoir to perform various tasks, rather than evolving the tasks directly. Next was another carbon nanotube talk, here having them in liquid crystal rather than frozen in polymer, allowing them to move to form clusters, to help their computational performance. The third talk changed tack, on to memristor logic. It appears that memristors natural support a ternary logic rather than the classical binary logic, and naturally implement different kinds of gates.  Finally, we had a talk that started with Zuse’s mechanical computer, and ended up with a “three cog, one gate” universal computer.

A great start to the conference.

Mancunicon Eastercon - Monday

The last day of the Mancunicon Eastercon started (after the traditional mushroom-rich breakfast) with a panel on The Deeper the Grief, the Closer to Life?, or “the cheerful panel”, about grief, death, and other forms of loss.  Grief is due to loss; death is the most common loss, but you can be grief-stricken over the loss of a pet, some much loved artefact, or separation from a person or place, or even in anticipation of loss, especially due to slow dying and dementia.  The loss is a loss of a part of yourself, and you have to restructure yourself. Hence rituals for death: funerals, wakes, provide community support.  Revenge is a plot device to avoid dealing with grief.  The classic five stages of grief are: denial, anger, bargaining, depression, acceptance.  SF tries to deny death with immortality or time travel, but this can lead to grief due to the inability to die.  Death is a subtext of all the new Doctor Who.  Much of Tolkien is the world grieving for a lost way of life. Authors can feel loss on finishing writing a book: leaving all those characters behind.

Then our final item was Farah Mendlesohn in conversation with Guest of Honour Dave Clements.  This covered his professional life in astronomy, and his fannish life in conrunning.

We debated whether to stay for a final item, but decided instead to hit the road and drive home.

So, another Easter, another con.  As ever, this one was full of fun, interest, cleverness, and unexpected information.  Next year, in Birmingham!

Mancunicon Eastercon - Sunday

The first item for Sunday at the Mancunicon Eastercon was a panel on Terraforming Planets and Living in Space in SF, excellently chaired by Helen Pennington, who used a sequence of well-designed questions to move her panelists through an interesting discussion.  The scope gradually increased, from bases in orbit, to the moon, solar system planet, and beyond.  Ian McDonald is taken with the idea of moon bases, because people on earth would be able to look up and see the lights on the moon.  We could try terraforming Venus with earth extremophiles: take a few litres of silt from the deep sea tranches, and see what happens; it could destroy any Venusian life, thereby following a long earth tradition.  The discussion moved on the economics of generation ships, travel between colonies, and how to contain diseases (you can’t).

The panel If You Don’t Scream You’ll Laugh discussed how to blend horror and comedy. There were varied attempts to define both horror and comedy, which led on to a definition of cognitive dissonance.  Both horror and comedy are a tone that can be used in any genre.  By adding a layer of comedy, it is possible to go deeper into the dark, and laughter can be a reaction to unease: black humour is daring the audience to laugh.  Horror can sometime be unintentionally funny when it just gets ridiculous.  Humour is cultural: Americans laugh at Hamlet.

Next came a panel on Book Reviews in the Age of Amazon.  Since I’ve been reviewing (nearly) all the book I read for (nearly) 20 years, I was interested to see what people thought of reviews. One of the panelists writes his reviews for exactly the same reason I write mine: to help us remember what we have read.  The panel drew a distinction between an opinion, a review (a supported opinion), and a critique (a more objective, analytical review).  You don’t have to enjoy, or even read, a book to enjoy a good critique of it.  (So my own pieces range from opinions to reviews, and are definitely not critiques.)  Blog reviews aren’t important for sales: a terrible review in the New York Times will sell more books than a great review on a blog.  But some Amazon reviews are in fact critiques: seek these out; the 1 star and 5 star reviews are telling you what the reviewer thinks; critiques will tell you whether you will like it.

Next was Kari Sperring in conversation with Guest of Honour Aliette de Bodard.  This covered a range of topics from demons in her fictional Paris, to Vietnamese language and cooking.

This segued nicely into a panel on Food, Glorious Food – Cooking in SF&F.  One panelist, describing moving house: I had 120 boxes, 115 were books, half of which were cookbooks; the other 5 boxes were kitchen equipment.  Aliette de Bodard noted that the recipes on her website get as much traffic as her books.  Even when fiction includes food, which it doesn’t often (books can include not a single meal), it rarely talks about cooking it.  There are some earth species that eat infrequently: maybe some aliens eat only once a week?  What about cooking in zero g?  Most cooking techniques rely on gravity.  And, of course: To Serve Man.

After this, it seemed appropriate to round off the day with a nice meal with friends.

Mancunicon Eastercon - Saturday

Saturday at the Manchester Mancunicon Easter science fiction convention started in the traditional way, with a cooked breakfast including a generous serving of mushrooms.  We then made the mistake of returning to our 4th floor room, to pick up our stuff for the day.  It was a mistake, because the 23-floor hotel has a paltry three lifts and no (usable) stairs.  After a 20 minute wait, seeing lifts fly by, or full lifts stopping, we finally managed to squeeze in one.  But because of this we arrived late for the 10am session (Dave Clements’ talk on How Space Science Happens), to find the room packed to overflowing.  So we went to the Art Show instead.  And didn’t make the mistake again of trying to use the lifts during the day.

So the first talk of the day for us was Rachel Dickinson’s BSFA lecture on Crafting the Future: Ruskin, Textiles and Visions of Futures Past.  As usual at EasterCons, the annual BSFA lecture was excellent.  Ruskin was all about individual making aesthetically good and beautiful choices, particularly through choice of textiles and clothing: a universal interest, for everyone wears clothes, which should be comfortable, functional and attractive.  He contrasted individual-based craft work with the mass produced products of the grim, dark textile mills blighting the landscape around Manchester.  What was fascinating was the reaction of the mill owners: some wrote to Ruskin explaining that they would go out of business, with accompanying loss of employment for their workers, if they followed his approach.  He was aware of the issues, and wanted people to follow the overall picture, if not all the details.  Is this a more realistic vision today?

After the BSFA lecture was the annual George Hay memorial lecture, sponsored by the Science Fiction Foundation.  This year Colin Wright spoke on The Mathematics of Juggling.  Hilarious, brilliant, a technical tour de force (complex juggling while talking!), and with some deep maths to explain the patterns, leading to the deduced need for a time-travelling ball.  He’s going to be a hard act to follow.  The admiration was a two way street: he complimented the audience for getting all his technical and SF jokes.

Next came a talk by Verity Allen, on Designing the Supercomputer for the World’s Largest Radio Telescope.  The radio telescope is the proposed Square Kilometre Array, and it will produce a truly prodigious amount of data: 5 thousand Petabytes/day (1 PB = 1000 TB) initially, then up to 100 thousand PB/day if phase 2 gets built.  This amount of data offers interesting engineering issues, covering input, storage, buffering, memory bandwidth, and processing.  And they need to architect the system for hardware that hasn’t been invented yet.

Then off to hear Ian Whates in conversation with Guest of Honour Sarah Pinborough.  This included discussion of why she went into teaching (the grant was better than the alternative wage) and her pupils’ reaction to being shown The Texas Chainsaw Massacre, her ex-father-in-law coming to live with her while he was dying, and, sometime, her books.  Hilarious and eye-opening.

The Ecology of Doctor Who had Smuzz talking through how stories in Dr Who were alternately mirroring, or pointedly ignoring, a variety of ecological issues happening in mundania, backed by relevant clips (once the technology started working).

And continuing the Dr Who theme, we wrapped up the Saturday with  An Adventure in Time and Space: 53 Years in 53 Rels: the entire Dr Who canon performed by five people in 53(ish) of your earth minutes.  Rib-achingly funny, and clever.  The Reduced Shakespeare Company has a lot to answer for!

Mancunicon Eastercon - Friday

We left our friends to drive into the centre of Manchester to the Easter science fiction convention.  The con is in the Deansgate hotel, which recommended the snappily-named adjacent NCP Manchester Great Northern Warehouse car park for parking, at the special con rate of only(!) £12/day, reduced from the standard £20.50/day.  This car park is accessed from Watson Street.  We discovered there is another Watson Street, in the suburbs, thanks to the sat nav.  So we arrived a little later than planned, but still in good time.

The first session I attended was a panel I was on: the Comma Press sponsored (Don’t) Ask the Scientist.  This revolved around bad science in SF, and whether the author has a responsibility to get the science right.  I caused a minuscule amount of controversy by saying they didn’t – but I did add that they do have a responsibility to be honest.

Next was a panel on Twisting the Story: about the different kinds of plots twists, and how to do them well.  One writer revealed their secret: “I once discovered I needed a twist.  So I went and read the book as it was so far, reading as if I knew author had set up a brilliant twist. And I found one!”

Ian McDonald at Mancunicon

Guest of Honour Ian McDonald was interviewed by Peadar Ó Guilín.  He spoke about how he sets his novels in places where he can go and do tax-deductible research: Brazil, India, and the like. His latest novel is set on the moon…

The panel Revealing History, Revealing Now examined whether the history in historical fantasy or alternate history fiction needs to be right.  (Clearly “being right” is a perennial theme in the SFnal community.)  And if you make a change, particularly to introduce a fantastical element, you need to think through the consequences of that change: it will affect the rest of the world, too.  The important point is that the real history is usually much richer and more diverse and stranger than the history we are taught, and that is enough to make readers think the author has it wrong.  Beware governments who try to control the history curriculum: look carefully at what they want the children to believe about where they and others have come from.

In the evening we had the panel What’s the Worst That Could Happen?, or, good ways to kill a lot of people.  After the panel introduced themselves, they realised a problem: none of the panellists is really an expert in mega-death.  Or maybe that’s not a problem…  The discussion riffed off solar flares, disease, revolutions causing famines, resource exhaustion, asteroids, nuclear war, bioweapons, climate change, ice ages, super-volcanoes, rogue black holes, gamma ray bursts, and Vogons.  We don’t have the ability to reboot civilisation after a global catastrophe, and so we need to colonise space to avoid most of the problems.  Just your standard apocalyptic scenarios, then.

We rounded off the evening watching a session of Whose Line is it Anyway?, with various improvised scenarios.

it's dead, Jim

I arrived home on Friday evening, after a four hour train journey back from a meeting in Manchester. [Small rant: as we were coming into Nottingham, there was an announcement: "for those of you travelling beyond Nottingham, this train splits here.  Please make sure you are in the rear mumble coaches if you want to travel beyond Nottingham." It wouldn't have helped me even if I could have made out the mumble.  I had no idea which coach I was in (a very long train arrived at Manchester; I got on it somewhere; the train changed direction at Sheffield, confusing my already weak grasp on reality.)  I have a suggestion for these sorts of trains: make the announcement only in the "wrong" coaches, and tell people there that they have to move.]

Anyhow, I got home. I had tea.  I went to my study to switch on my computer.  Nothing.  Did all the obvious things.  Still nothing.  Dead as a nit.

Well, it is nearly 8 years old, so I'm probably due an upgrade.  So I spent a pleasant time speccing up a dream replacement, then down-speccing it to a more reasonable price.

But ... I'd arrived home (near Cambridge) by train.  The car is in still at work, in York.  I can't get to the computer shop until next weekend.  I'm having to making do with this little laptop that has none of my standard software on it.  Grump.

Oh, what first world problems we suffer!

Still, being without a computer this weekend isn't the disaster it might have been.  I have a pile of exam scripts to mark, and no time to surf do important computery stuff, anyway.